1st/2nd/4th Review Project Collection #2
Learning Objective 1.32: The student is able to justify the selection of geological, physical, and chemical data that
reveals early Earth conditions.
Science Practice 4.1: The student can justify the selection of the kind of data needed to answer a particular scientific
question.
Explanation:
At Earth’s beginning, there was very little oxygen, and a lot of
water, methane, carbon monoxide, and carbon dioxide. There was no ozone
layer which led to high levels of UV radiation, and lots of meteorite
bombardment. There was a lot of lightening and volcanic activity. Through
absolute and relative dating of fossils and rocks, and the knowledge that the
environment was too hostile for life until 3.9 byo, we can conclude that the
origin of life occurred between 3.5 and 3.8 billion years ago. The oldest rocks
were found in Greenland 3.8 billion years ago, and the oldest fossils were
dated to 3.5 byo. In 1953, the Miller-Urvey experiment was conducted to see
if Earth favored reactions that formed organic compounds from inorganic
compounds, which was a hypothesis made in 1920 by Oparin and Haldane.
Through repeated experiments, they concluded that all monomers necessary
for life (amino acids, all the components of nucleotides, sugars, lipids, etc.)
could be formed from inorganic compounds. This gave evidence that living
matter can come from lifeless matter, and that this is how the earth was
formed since it started out with no living matter but had an abundance of
free energy and barely any oxygen. These monomers connected to make
polymers as Syndey Fox proved by dripping monomers onto hot sand, clay, or
rocks to see if they would connect. These connected monomers created
protienoids which are poly peptides created by abiotic means. These
protienoids gave way to protobionts which are abiotically produced molecules
surounded by a membrane. We believe that eukaryotes originated through
endosymbiosis which is when molecules absorb one another and live inside of
each other. This is proven by the similarities between bacteria and
mitochondria & chloroplasts. They both reproduce by binary fission, have
small, circular genomes, and very similar DNA sequences , along with many
others. Current endosymbiotic relatationships also provide evidence… it had
to start sometimes, so it could have been then. How similar all organisms DNA
sequences/amino acid composure is a sign that we all are evolved from one
organism and so we conclude that there is a common genetic code. There is
some evidence that RNA was the first genetic material because through
ribozymes, RNA can self replicate and the RNA molecules best suited for their
environment replicate their DNA and reproduce so natural selection has an
impact. The origin of photosynthesis tells us what the atmosphere was like
during early times because the cyanobacteria used to have a bacteria that
metabolized dihydrogen sulfide, and that bacteria mutated to use water.
Water was abundant in the atmosphere at that time so the cyanobacteria
used it in photosynthesis. The oxygen that was released from the
photosynthesis reacted with dissolved iron and formed oxide precipitate and
the saturated water was released into the atmosphere.
Multiple Choice:
Which of the following statements about the
conditions of Earth’s beginning and the scientific evidence that
proves that condition is TRUE?
(a) The cyanobacteria’s bacteria that metabolized dihyrogen
sulfide mutated to use water rather than dihydrogen sulfide,
which proves that the Earth’s atmosphere in early times had an
abundance of dihydrogen sulfide.
(b) The cyanobacteria’s bacteria that metabolized dihyrogen
sulfide mutated to use water rather than dihydrogen sulfide,
which proves that the Earth’s atmosphere in early times had an
abundance of water.
(c) The percent of common amino acids in all organisms proves
that the theory of evolution is invalid.
(d) Monomers combined to make polymers which indicates that
there were great amounts of volcanic activity in Earth’s early
years.
FRQ: Explain the process of the origin of life on Earth and the
scientific evidence that supports these theories. Begin with no
life, and end with the formation of eukaryotes. Make sure that
you include information about how natural selection contributed
and cite the names of any scientists who contributed
experimental data to help solidify this theory.
FRQ Answer: The Miller-Urvey experiment was conducted to see if Earth
Answer Key
•
Multiple Choice Question and Answer:
Which of the following statements about the
conditions of Earth’s beginning and the scientific
evidence that proves that condition is TRUE?
(a) The cyanobacteria’s bacteria that metabolized
dihyrogen sulfide mutated to use water rather than
dihydrogen sulfide, which proves that the Earth’s
atmosphere in early times had an abundance of
dihydrogen sulfide.
(b) The cyanobacteria’s bacteria that metabolized
dihyrogen sulfide mutated to use water rather
than dihydrogen sulfide, which proves that the
Earth’s atmosphere in early times had an
abundance of water.
(c) The percent of common amino acids in all
organisms proves that the theory of evolution is
invalid.
(d) Monomers combined to make polymers which
indicates that there were great amounts of volcanic
activity in Earth’s early years.
B is the correct answer. The other options are all wrong.
favored reactions that formed organic compounds from inorganic
compounds, which was a hypothesis made earlier by Oparin and Haldane.
Through repeated experiments, they concluded that all monomers necessary
for life (amino acids, all the components of nucleotides, sugars, lipids, etc.)
could be formed from inorganic compounds. This gave evidence that living
matter can come from lifeless matter, and that this is how the earth was
formed since it started out with no living matter but had an abundance of
free energy and barely any oxygen. These monomers connected to make
polymers as Syndey Fox proved by dripping monomers onto hot sand, clay,
or rocks to see if they would connect. These connected monomers created
protienoids which are poly peptides created by abiotic means. These
protienoids gave way to protobionts which are abiotically produced
molecules surounded by a membrane. Natural selection then comes in to
play because protobionts best suited for their enviroment could reproduce
and create others who were best suited for their enviroment. Coacervate is
a stable protobiont droplet that self assembles when a suspension of
macromolecules are shaken. Since we know that macromolecules can be
created in earth’s hostile enviroment due to the findings of Miller and Urvey,
we know that protobionts can also be formed. We believe that eukaryotes
originated through endosymbiosis which is when molecules absorb one
another and live inside of each other. This is proven by the similarities
between bacteria and mitochondria & chloroplasts. They both reproduce by
binary fission, have small, circular genomes, and very similar DNA sequences
, along with many others. Current endosymbiotic relatationships also proof
that it could have been responsible for forming eukaryotes so early because
it had to have started at some point in the history of the Earth, so why not in
the very beginning?
(LO 4.4) The student is able to make a prediction about the interactions of subcellular organelles.
(SP 1.5) The student can make claims and predictions about natural phenomena based on scientific theories
and models.
A eukaryotic cell has membrane-enclosed organelles, the largest of which is
usually the nucleus. A prokaryotic cell is usually smaller and does not
contain a nucleus or other membrane-enclosed organelles. Some
organelles are animal or plant specific, but these SEVEN organelles
are found in both types of cell: the nucleus, vacuole, mitochondria,
the Golgi apparatus, cytoskeleton, peroxisomes, and the
Endoplasmic reticulum (ER). The nucleus includes the nuclear
envelope, the nucleolus, and chromatin, and is the information center
of the cell. A vacuole is a membrane-bound sac that contains
hydrolytic enzymes that aid in intracellular digestion and the release
of cellular waste products. There is a central vacuole in plant cells.
Mitochondria aid in energy capture and transformation. The Golgi
apparatus, consisting of a series of flattened membrane sacs (called
cisternae), synthesizes and packages small molecules for transport in
vesicles, and produces lysosomes (described later). The cytoskeleton
reinforces the cell’s shape. The ER consists of a smooth and a rough
ER. The rough ER gets its name from its surface containing ribosomes
(small structures containing rRNA and protein) and is where protein
synthesis occurs and contributes to intracellular transport. Ribosomes
can be free ribosomes (suspended in the cytosol) or bound ribosomes
(attached to the outside of the ER or nuclear envelope). The smooth
ER synthesizes lipids. Peroxisomes are organelles that aid in
metabolism and produce hydrogen peroxide.
MC Question:
The endomembrane system is a complicated system involving
multiple organelles. Which of the following correctly describes the
movement through this system of a protein that functions best in
the ER?
A. The mRNA is synthesized in the ER, translated on a free ribosome
to the Golgi, and then a transport vesicle carries the mRNA back to
the ER for modification. The mRNA is then sent to the nucleus.
B. The mRNA is synthesized in the Golgi, is translated on a free
ribosome to the ER for modification, and then a transport vesicle
carries the mRNA back to the Golgi.
C. The mRNA is synthesized in the nucleus, is translated on a free
ribosome, then is sent to the Golgi and modified. A transport
vesicle carries the protein to the ER for further modification.
D. The mRNA is synthesized in the nucleus, is translated on a bound
ribosome, then is sent to the ER and modified. A transport vesicle
carries the protein to the Golgi apparatus. After modification in the
Golgi, another transport vesicle carries the protein back to the ER.
FRQ Question:
Organelles are found in both prokaryotic and eukaryotic cells.
Plant cells include chloroplasts, organelles that contribute to energy
a. Compare and contrast prokaryotic and eukaryotic cells.
capture and conversion for photosynthesis. Animal cells contain
b. List and describe the basic function of three organelles.
lysosomes, which aid in intracellular digestion, apoptosis, and
c. Describe how these organelles work together to allow the animal
recycling cell material. Centrosomes are organelles where the cell’s
microtubules are initiated, but in animal cells these organelles contain cell to function.
centrioles (function unknown). Plant cells also contain a cell wall, with
plasmodesmata (channels) throughout, that help keep the cell’s
shape and protect the cell from mechanical damage. (next slide has
visuals)
Organelle Interactions
Now that we know the functions of the organelles,
let’s look at how they interact…
The nucleus houses the most of the cell’s
DNA and the ribosomes use
information from the DNA to make
proteins. Vesicles move from the ER
to the Golgi. Vesicles form and leave
Golgi, carrying specific proteins to
other locations or to the plasma
membrane for secretion. Vesicles
also transport certain proteins back
to the ER. These vesicles give rise to
lysosomes and vacuoles. Lysosomes
are then available for fusion with
another vesicle for digestion.
Transport vesicles carry proteins to
the plasma membrane for secretion.
The Plasma membrane expands by
fusion of the vesicles and the
proteins are secreted from the cell.
This makes up the endomembrane
system. In addition to this system,
mitochondria (animal cells) and
chloroplasts (plant cells) contain DNA
and change energy from one form to
another.
Answer Key- LO 4.4
FRQ:
Organelles are found in both prokaryotic and eukaryotic cells.
a. Compare and contrast prokaryotic and eukaryotic cells.
b. List and describe the basic function of three organelles.
c. Describe how these organelles work together to allow the
animal cell to function.
MC Question:
The endomembrane system is a complicated system involving
multiple organelles. Which of the following correctly describes a
the movement through this system of a protein that functions
best in the ER?
A. The mRNA is synthesized in the ER, translated on a free
ribosome to the Golgi, and then a transport vesicle carries the
mRNA back to the ER for modification. The mRNA is then sent
to the nucleus.
B. The mRNA is synthesized in the Golgi, is translated on a free
ribosome to the ER for modification, and then a transport
vesicle carries the mRNA back to the Golgi.
C. The mRNA is synthesized in the nucleus, is translated on a
free ribosome, then is sent to the ER and modified. A
transport vesicle carries the protein to the Golgi apparatus.
After modification, another transport vesicle carries the
protein back to the ER.
D. The mRNA is synthesized in the nucleus, is translated on a
bound ribosome, then is sent to the ER and modified. A
transport vesicle carries the protein to the Golgi apparatus.
After modification in the Golgi, another transport vesicle
carries the protein back to the ER.
The question requires background about the difference
between bound and free ribosomes, the functions of each
organelle in the endomembrane system, and the relationship
between the different organelles in the system. First, the
student must understand that the order of the
endomembrane system, with the specified protein from the
question, is: nucleus, ER, Golgi, back to the ER (since the
protein functions best in the ER). This eliminates A and B.
Between C and D, D is the only answer choice that has the
correct order and mentions a bound ribosome. Understanding
that this protein requires a bound ribosome is important
because bound ribosomes are attached to the rough ER.
a. A eukaryotic cell has membrane-enclosed organelles, the
largest of which is usually the nucleus. A prokaryotic cell
is usually smaller and does not contain a nucleus or
other membrane-enclosed organelles. Prokaryotes
contain a single circular chromosome, while eukaryotes
contain multiple linear chromosomes.
b. Three animal cell organelles are the Golgi apparatus, the
nucleus, and the ER. The Golgi apparatus, consisting of a
series of flattened membrane sacs (called cisternae),
synthesizes and packages small molecules for transport
in vesicles, and produces lysosomes. The nucleus
includes the nuclear envelope, the nucleolus, and
chromatin, and is the information center of the cell. The
ER consists of a smooth and a rough ER. The rough ER
gets its name from its surface containing ribosomes
(small structures containing rRNA and protein) and is
where protein synthesis occurs and contributes to
intracellular transport. Ribosomes can be free ribosomes
(suspended in the cytosol) or bound ribosomes
(attached to the outside of the ER or nuclear envelope).
The smooth ER synthesizes lipids.
c. The nucleus houses the most of the cell’s DNA and the
ribosomes use information from the DNA to make
proteins. Vesicles move from the ER to the Golgi.
Vesicles form and leave Golgi, carrying specific proteins
to other locations or to the plasma membrane for
secretion. Vesicles also transport certain proteins back
to the ER. These vesicles give rise to lysosomes and
vacuoles. Lysosomes are then available for fusion with
another vesicle for digestion. Transport vesicles carry
proteins to the plasma membrane for secretion.
•
•
•
LO 1.19: The student is able to create a phylogenetic tree of simple cladogram
that correctly represents evolutionary history and speciation from a provided
chart.
SP 1.1: The student can use representations and models to communicate
scientific problems.
Explanation: Phylogenetic trees serve to represent speciation that occurs deriving or losing
traits through evolution. Relatedness of organisms is shown by how recently the two
diverged into different branches, which also shows common ancestors of the two. They are
constructed by comparing the similarities of fossils and DNA of species. The more two
different species have in common, the more recently they diverged. Since evolution is a
continuous process, phylogenetic trees and cladograms are constantly being revised in
accordance to newly emerged knowledge.
•M.C. Question: The chart below shows differences in amino acids between four
insects and a wolf spider. Using the chart, determine which two organisms most
likely diverged most recently.
A. beetle and wolf spider
B. cricket and grasshopper
C. lady bug and beetle
D. Wolf Spider and the lady bug
FRQ: Using the information in the chart below, create a cladogram of the
evolutionary patterns of the given organisms. Explain why the cricket and grass
hopper should go on the same branch.
Expain two patterns of evolution and how speciation occurs as a result.
ladybug
beetle
Cricket
Grass
hopper
Wolf
spider
Ladybug
beetle
cricket
Grass
Hopper
Wolf
Spider
0
2
10
15
25
0
5
7
26
0
1
22
0
16
0
Multiple Choice answer
•
M.C. Question: The chart below (slide two) shows differences in amino acids between four
insects and a wolf spider. Using the chart, determine which two organisms most likely
diverged most recently.
– A. beetle and wolf spider
– B. cricket and grasshopper
– C. lady bug and beetle
– D. Wolf Spider and the lady bug
–
C is the correct answer because the lady bug and the beetle have only one difference in amino
acids. All the other choices have more differences, so the lady bug and beetle are most similar.
•
FRQ: Using the information in the chart below, create a cladogram of the
evolutionary patterns of the given organisms. Explain why the cricket and grass
hopper should go on the same branch.
–
–
–
–
Explain the difference between allopatric and sympatric speciation.
Below is an example of an appropriate cladogram answer. The cricket and grass hopper belong on
the same branch because they differ by only one amino acid, so it can be assumed that their
speciation occurred recently in evolutionary time.
Allopatric: An extrinsic factor prevents two or more groups of a species from mating regularly,
which will eventually cause a difference in the gene pool and then speciation.
Sympatric: A change in the gene pool with no geographic change or barrier in the environment. So
even though the population still occupies the same area together, they will not mate and will
eventually diverge because of changes in the gene pool.
cricket
Wolf spider
Grass
hopper
beetle
Lady bug
LO 2.26: The student is able to analyze data to identify phylogenetic patterns or relationships, showing that homeostatic
mechanisms reflect both continuity due to common ancestry and change due to evolution in different environments.
Science Practice 5.1: The student can analyze data to identify patterns or relationships.
Explanation: Phylogeny is the development or evolution of a particular group of organisms. Examining fossils is a common
method of seeing when groups of organisms diverged. Structures of organisms are also observed, which are divided into
analogous structures and homologous structures. Analogous structures are those that have similar functions but which
evolved separately within different groups of organisms and come from convergent evolution. Homologous structures have
similar organs but different functions, and come from a common ancestor, or from divergent evolution. There are graphs
and charts, such as phylogenetic trees and cladograms, that display evolutionary relationships.
MC Question: Suppose you have encountered a dead house finch and conclude that the structure of the bird’s wing is like
that of a wasp. Which of the following best describes the relationship between the structures of the organisms’ wings?
A) Homologous structures because the finch and wasp derived from a shared common ancestor.
B) Analogous structures because the finch and wasp derived from a shared common ancestor.
C) Vestigial structures because the finch and wasp have converged over time to show a similar structure of wings, yet they
did not come from a common ancestor.
D) Analogous structures because the finch and wasp have converged over time to show a similar structure of wings, yet they
did not come from a common ancestor.
Learning Log Question: In order to discover common ancestry, what might people use to study if organisms derived from a
common ancestor? (Cues: phylogenetic tree, cladogram, DNA, traits)
MC Question: Suppose you have encountered a dead house
finch and conclude that the structure of the bird’s wing is like
that of a wasp. Which of the following best describes the
relationship between the structures of the organisms’ wings?
A) Homologous structures because the finch and wasp
derived from a shared common ancestor.
B) Analogous structures because the finch and wasp derived
from a shared common ancestor.
C) Vestigial structures because the finch and wasp have
converged over time to show a similar structure of wings, yet
they did not come from a common ancestor.
D) Analogous structures because the finch and wasp have
converged over time to show a similar structure of wings,
yet they did not come from a common ancestor.
D is the correct answer because the bird’s wing may be
similar in appearance to the wasp’s but obviously did not
come from a common ancestor, considering that one is a
mammal and the other is an insect. This is known as
convergent evolution. This makes the structures analogous
structures. A is incorrect because the two organisms do not
come from a common ancestor. B is incorrect because the
definition given is for homologous structures, not analogous.
C is incorrect because vestigial structures are structures that
are no longer in use.
Learning Log Question: In order to discover common
ancestry, what might people use to study if organisms
derived from a common ancestor? (Cues: phylogenetic
tree, cladogram, DNA, traits)
Cladograms are very helpful in showing
common ancestry. Cladograms
demonstrate ancestral relations
between organisms by showing which
traits organisms share and do not share.
They can be used to show where an
organism may have branched from one
another, taking a different path. This
makes cladograms very effective in
finding phylogenetic relationships.
Another useful method is constructing
phylogenetic trees. Constructing these
trees help to compare similarities of
characteristics or DNA sequences of
organisms. If there is common descent,
phylogenetic trees should project neat
lines of inheritance and ancestry.
LO 2.9: The student is able to represent graphically or model quantitatively the exchange of molecules between an organism and its
environment, and the subsequent use of these molecules to build new molecules that facilitate dynamic homeostasis, growth, and
reproduction.
SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain.
SP 1.4: The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively.
Explanation: Many organisms intake molecules from the environment for respiratory purposes, to generate energy for
cellular work, such as synthesis and arrangement of molecules, or otherwise for doing work. For example, the Euglena
protist, an organism with a chloroplast, is capable of photosynthesic light reactions where light is converted into NADPH
and ATP, compounds which are then synthesized with CO2 into sugars in the dark reactions, and the sugars will be stored
into cell chemical bonds as a energy supply to be oxidized in cell respiration during the nighttime.
Knowing this, the exchange of molecules (light, oxygen, carbon dioxide, etc.) can be represented by respiration, a process by
which thermodynamic homeostasis (regulation) may be maintained in a body, while also supplying the organism with ATP
molecules that will provide energy for metabolic and reproductive processes, among other cellular processes.
The graph shows an experiment in which germinating pea seeds represent organisms
that respire, replacing oxygen with carbon dioxide at a 1:1 molecule exchange ratio.
The oxygen thus is measured by the volume of solid potassium carbonate that is
formed when cotton treated with potassium hydroxide (KOH) reacts with CO2.
Diagram:
Multiple Choice:
Which of the following cellular respiration pathways represented by a diagram
will produce the most energy for cellular processes?
a.
b.
c.
d.
Free Response:
For each of the cases, describe how ATP and/or metabolism is used to facilitate the organism’s
ability to survive.
a) A salmon exhibits osmoregulation of NaCl.
b) Certain mammals are capable of thermoregulation.
c) Plants construct carbohydrates out of the products of photosynthesis.
Multiple Choice:
The correct answer is C, as it represents the Electron Transport Chain, which encompasses the two processes of
chemiosmosis and oxidative phosphorylation. Using the carriers of FADH2 and the NAD+, H+ is transported across a
gradient to support the ATP synthase which will phosphorylate ADP to form ATP. This metabolic pathway provides the
most ATP with about 26-28 ATP molecules.
a. and b. are represented by glycolysis and the Krebs cycle, which sets up and pyruvates and then uses it to form acetyl
coenzyme-A and electron carriers, respectively. As such, they only generate about 2 molecules of ATP. D. represents
fermentation, which is anaerobic respiration and thus won’t generate sustainable amounts of ATP.
Free Response:
a)
b)
c)
salmon have a special enzyme that hydrolyzes ATP and uses the released energy to actively transport
Na+ and Cl- ions against their concentration gradients. These Na+-Cl- ATPase molecules 'pump' Na+and Clout of the salmon's blood into water, thus being resistant to NaCl overload.
In marine mammals, they can increase ATP production (increasing metabolism), and ATP can be used as
heat (generation of energy). As the ATP production increases, the oxygen consumption, and circulation
also increase.
In the Calvin cycle, plants use ATP as the primary energy source and reduces NADPH through three phases:
Carbon fixation, Reduction of ATP and NADPH into G3P (glyceraldehyde 3-phosphate) 3-carbon
carbohydrate, and Regeneration, using ATP to reform RuBP observed in carbon fixation (ribulose
biphosphate) to make a round trip and continue the cycle of making sugars.
LO 3.18: The student is able to describe the connection between the regulation of gene
expression and observed differences between different kinds of organisms.
SP 7.1: The student can connect phenomena and models across spatial and temporal scales.
Explanation: DNA regulatory sequences, regulatory genes, and small regulatory RNAs are involved in gene expression. Regulatory sequences are stretches
of DNA that interact with regulatory proteins to control transcription, (examples are promoters, terminators, or enhancers). A regulatory gene is a
sequence of DNA that codes for RNA. In bacteria and viruses control mechanisms are used to regulate gene expression. These control mechanisms can
either be positive or negative. Inducers have the power to turn on the expression of a gene, while repressors can inhibit it. Both inducers and repressors
interact with regulatory sequences or regulatory proteins. These regulatory proteins can be a positive control and stimulate gene expression by binding to
DNA and stimulating transcription, or they can be negative controls by blocking transcription and inhibiting gene expression. Genes such as the ribosomal
genes are always turned on because they are continuously expressed. Gene expression is a complicated process and involves regulatory genes/elements,
and transcription factors in eukaryotes. These transcription factors bind to specific DNA sequences and some of them are activators while others are
inhibitors. A combination of the transcription factors is ultimately what controls how much gene product will be produced at any given time. This Gene
regulation accounts for phenotypic differences in a population. Phenotypic differences are also known as observed differences.
Multiple Choice Question: The Arctic Hare undergoes a complete transformation when the seasons change. In the
summer, the Hare is a brown color, but when winter arrives, his fur color changes to a pure white. How does the climate
of polar regions influence this change in gene expression?
a) Over heating causes the fur to loose its color.
b) Colder conditions cause gene regulation shifts to help the hare
camouflage and preserve body heat.
c) The hare doesn’t have enough pigment molecules to last all year so
they are saved up during the winter
d) Colder conditions cause the mitochondria to work faster and less efficiently,
draining the hare of color.
e) Climate has no effect on the hare’s color change
Learning Log/FRQ-style Question:
a. Using the model for the action of enhancers and transcription activators,
label RNA Polymerase II, the DNA bending protein, activators, enhancers,
promoters, and TATA box. Next, describe the role each of these parts plays in
the process of the transcription initiation complex.
b. Explain how a mistake in the transcription process may cause physical
changes to an organism, and possibly the organisms entire species over time.
Multiple Choice Answer: The Arctic Hare undergoes a complete transformation when the seasons change. In the summer,
the Hare is a brown color, but when winter arrives, his fur color changes to a pure white. How does the climate of polar
regions influence this change in gene expression?
a) Over heating causes the fur to loose its color.
b) Colder conditions cause gene regulation shifts to help the hare
camouflage and preserve body heat.
c) The hare doesn’t have enough pigment molecules to last all year so
they are saved up during the winter
d) Colder conditions cause the mitochondria to work faster and less efficiently,
draining the hare of color.
e) Climate has no effect on the hare’s color change
Over heating is not an issue in this cold environment, pigment molecules cannot be “saved up”, and fur color has nothing to
do with the effectiveness of the mitochondria. The hare does, however, need to conserve body heat in the winter and with
snow on the ground white camouflage keeps it hidden from predators.
Learning Log/FRQ-style Answer:
Activators
a.
Promoter
Enhancer
TATA Box
DNA Bending Protein
RNA Polymerase II
Activators – Bind to distal
control elements
Enhancer – Has three binding
sites, accepts the activators
Promoter – Sequence that tell
other molecules where
transcription begins
TATA Box – Defines the
direction of transcription and
also indicates the DNA strand
to be read.
DNA Bending Protein – Brings
the bound activators closer to
the promoter
RNA Polymerase II – Catalyzes
the transcription of RNA
b. Mistakes in the transcription process
lead to incorrect amino acid
sequences. These incorrect amino
acids lead to mutations in an organism.
Although sometimes these mutations
aren’t visible, often they are. When
the mutation offers an advantage to an
organism, they become best fit for
survival and the trait is passed to
younger generations and the
generations that follow.
Learning Objective: 4.23 The student is able to construct explanations of the influence of
environmental factors on the phenotype of an organism.
Science Practice: 6.2 The student can construct explanations of phenomena based on
evidence produced through scientific practices.
Explanation: The phenotype of many organisms is dependent upon the environment. Environmental changes, both
abiotic and biotic, occur every so often and they can force the organisms to either change phenotypes to adapt to the
environment or die out. The changes in phenotypes of organisms is caused by changes in allelic frequencies
throughout the population. Even though genotype is a critical part of development, it is the environmental factors
such as temperature, diet, and availability of food that influence the phenotypes throughout an organism’s life.
M.C. Question: All of the following would be an example of a phenotypic change in an
organism due to environmental factors EXCEPT:
A. A polar bear population in Antarctica’s fur coat becomes increasingly thinner as time
goes by and the climate gradually becomes warmer.
B. Two lion cubs are wrestling and one cub pulls a chunk of fur out of the other cub. This
causes the second lion cub to have a permanent bald spot on the back of it’s head.
C. A certain species of moth changes from lightly colored to black colored following the
Industrial Revolution in order to be camouflage to the trees that have turned darker
because of the new pollution that killed the lichens that were previously on the trees.
D. A pair of twins are raised together until the age of 18. When they are 18 years old one
twin goes to work in an office and the other twin works as a construction worker. The
twin that works as a construction worker develops much larger muscles than the twin
working in an office.
E. Finches in the Galapagos are exposed to different types of seeds and nuts to eat. The
finches that eat the nuts and seeds with harder shells to crack open develop thicker
and more durable beaks that the finches eating nuts and seeds in soft shells.
Learning Log/Free Response Question: Soon after the industrial revolution, the
phenotype of many peppered moths changed from very light to almost black coloring.
Peppered moths typically rest on trees. Choose an environmental factor that might have
impacted this change in phenotype and explain how this phenotypic change could have
been beneficial for the peppered moth species.
ANSWER KEY – LO 4.23
All of the following would be an example of a phenotypic change in an organism due to environmental factors
EXCEPT:
A. A polar bear population in Antarctica’s fur coat becomes increasingly thinner as time goes by and the climate
gradually becomes warmer.
B. Two lion cubs are wrestling and one cub pulls a chunk of fur out of the other cub. This causes the second lion
cub to have a permanent bald spot on the back of it’s head.
C. A certain species of moth changes from lightly colored to black colored following the Industrial Revolution in
order to be camouflage to the trees that turned darker because of the new pollution that killed the lichens
that were previously on the trees.
D. A pair of twins are raised together until the age of 18. When they are 18 years old one twin goes to work in an
office and the other twin works as a construction worker. The twin that works as a construction worker
develops much larger muscles than the twin working in an office.
E. Finches in the Galapagos are exposed to different types of seeds and nuts to eat. The finches that eat the nuts
and seeds with harder shells to crack open develop thicker and more durable beaks that the finches eating
nuts and seeds in soft shells.
Learning Log/FRQ: Soon after the industrial revolution, the phenotype
of many peppered moths changed from very light to almost black
coloring. Peppered moths typically rest on trees. Choose an
environmental factor that might have impacted this change in
phenotype and explain how this phenotypic change could have been
beneficial for the peppered moth species.
One environmental factor that could have caused this phenotypic change in the peppered moths could be the color of
the trees due to pollution from the industrial revolution. Pollution could kill the lichens that grow on trees and keep
them at a lighter color. This change in phenotype to a darker coloration would benefit the moths because they would
not stand out against the darker trees. Predators would not be able to spot the moths on trees as easily as they would
if the moth was lightly colored and the trees was dark and vice versa. The moths that were likely colored would be the
first to be eaten by predators and would not be able to reproduce moths with the same light coloring. Instead, those
moths with the dark coloration would survive and be able to reproduce offspring with the same genetic coding for dark
coloring.
LO 1.25: The student is able to describe a model that represents evolution
within a population.
SP 1.2: The student can describe representations and models of natural or
man-made phenomena and systems in the domain.
Explanation: For quite some time, there were many views on how evolution
occurred within populations of organisms. Lamarck had the model of use and
disuse, where parts of the body become larger and more helpful, and the
ones that are not used eventually disappear. This model, however, is
incorrect. Using Darwin’s correct theory, we now know more about the many
factors that cause evolution within populations, including environment,
predation, or other factors. Changes in allele frequencies and mutations
within a population can cause evolutionary changes in the organisms within a
population over a long period of time. Emergent diseases within a population
can also decrease the size of that population, making it lose important alleles
that can help it evolve when the environmental conditions change. The
Hardy-Weinberg theorem gives a basis of comparison for determining
evolutionary change within a population. It gives unrealistic, ideal situations
for a population, thus serving as a basis for comparison with any real
population that actually does undergo some sort of evolutionary change.
M.C. Question: In a population of mongooses, with genetic variation present
within this particular population, environmental pressures cause one of the
extreme colors of the mongooses to be favored out of all others within the
population. In other circumstance, with the same population, environmental
changes cause the extremes of both kinds in the mongoose population to be
favored. In a third circumstance, the changes in environmental pressures cause
only the mongooses with intermediate fur coat color to be favored out of the
population.
Which of the following statements accurately describes the phenomenon of
stabilizing selection?
a)
b)
c)
d)
Evolution favors only the extremely light colored rabbits out of the populaton.
Evolution favors only the intermediate colored rabbits out of the population.
Evolution favors only the extremely dark colored rabbits out of the population.
Evolution favors both the extremely light and dark rabbits out of the population.
Learning Log/FRQ-style Question: There are many types of unforeseen factors
that can alter the genetic composition of a population. Describe the phenomenon
of the bottleneck effect and give an example. Why is it very important that
humans have a knowledge of the bottleneck effect in terms of conservation?
M.C. Question and Answer: Which of the following statements accurately describes the phenomenon of
stabilizing selection?
a)
Evolution favors only the extremely light colored rabbits out of the populaton.
b)
Evolution favors only the intermediate colored rabbits out of the population.
c)
Evolution favors only the extremely dark colored rabbits out of the population.
d)
Evolution favors both the extremely light and dark rabbits out of the population.
It stabilizes the population, removing the extremes of the organism on both sides of the population over time.
Learning Log/FRQ-style Question and Answer: There are many types of unforeseen factors that can alter the
genetic composition of a population. Describe the phenomenon of the bottleneck effect and give an example.
Why is it very important that humans have a knowledge of the bottleneck effect in terms of conservation?
The bottleneck effect is caused by some sort of sudden change in the environment, usually by a
disaster. This could greatly reduce the size of the population. With only a small number of
survivors from the population, the new population may not have many of the qualities the larger
original population once had. This would mean that certain, important alleles from the
population may be lost forever. If a population of frogs was greatly reduced due to a massive
hurricane, it would lose valuable genetic qualities that may be gone for good. This may cause
them to eventually go extinct, mostly because there is very little room for evolutionary
improvement since they have so few alleles left. From a perspective of conservation, humans
need to be informed of the dangers of the bottleneck effect. Many of the activities humans do
are very harmful to wildlife populations, which can cause disasters for them, making the
bottleneck effect very common in these populations.
LO 1.18 The student is able to evaluate evidence provided by a data set in conjunction with a phylogenetic tree or a
simple cladogram to determine evolutionary history and speciation.
SP 5.3 The student can evaluate the evidence provided by data sets in relation to a particular scientific
question.
Explanation: Cladograms and phylogenetic trees serve to illustrate evolutionary relationships between various organisms throughout
time. They can be derived from traits including amino acid similarities/differences, similarities/differences in fossils, or relationships
among protein sequences. Often times, advanced computer programs are used to analyze these patterns and determine any type of
relationship. Constructing a handmade cladogram or phylogenetic tree is possible through the use of a table that may outline amino
acid differences, structural characteristics, etc. These diagrams may also reflect traits that have been lost throughout evolution, and
they may be used to determine if particular organisms share a common ancestor. Phylogenetic trees and cladograms are very
susceptible to frequent change due to constant updates of biological information and fossil records. When updated, however, they
provide extremely
accurate information regarding an organism’s ancestors,
evolutionary patterns and relationships with other organisms.
M.C Question: Consider the cladogram presented. Which organisms most
likely share the greatest number of derived characteristics?
A. Shark and turtle
B. Tuna and frog
C. Turtle and kangaroo
D. Human and kangaroo
E. Salamander and kangaroo
FRQ-style Question: The table below expresses differences in amino acids
among multiple animals. Using the data provided, draw a cladogram that
accurately represents the relationships between these organisms. Explain
your reasoning behind your drawing. Also, identify which organism is least
related to the turtle and explain your answer.
|Dog |Cow |Lemur |Ostrich |Turtle
Dog
0
2
13
15
19
Cow
0
12
14
18
Lemur
0
5
16
Ostrich
0
15
Turtle
0
Answer Key- LO 1.18
Consider the cladogram presented. Which organisms most likely share the greatest number of derived characteristics?
A. Shark and turtle
B. Tuna and frog
C. Turtle and kangaroo
D. Human and kangaroo
E. Salamander and kangaroo
D is the correct answer because they are located on the same branch of the cladogram, and they are
also both classified as amniotes and mammalia, implying a very close ancestral bond as well as
similarities in characteristics. The answer cannot be A because the two are not in the same
classification, and they share no branches on the cladogram. B is incorrect because the tuna is
classified as an osteichthyes, while the frog does not have a similar classification. C is not correct
because while they both belong to the amniote category, kangaroos are listed as mammals, while
turtles are not. Finally, E is incorrect because salamanders are shown as amphibians, while kangaroos
are mammals. Therefore, D must be the correct answer.
Using the data provided, draw a cladogram that accurately
represents the relationships between these organisms. Explain your
reasoning behind your drawing. Also, identify which organism is
least related to the ostrich and explain your answer.
- The relationships among the organisms were determined by the
amount of differences in amino acids- the more differences, the
less closely related, and the less differences, the closer the
relationship. For example, the dog and the cow are very closely
related due to only having two differences in amino acids. The dog
and the turtle, however, have 19 differences, reflecting very little
similarities between the two. The ostrich is least related to the dog,
according to the table. There are 15 amino acid differences
between the two organisms, which are more than the ostrich and
any other animal presented.
Cow
Ostrich
Turtle
Dog
Lemur
(sample cladogram)
LO 3.37 The student is able to justify claims based on scientific evidence that changes in signal transduction pathways
can alter cellular response.
SP 6.1 The student can justify claims with evidence.
Explanation: A signal transduction pathway takes place during cell communication. Cells communicate by using neurotransmitters for short distances and
hormones for long distances. The three stages of cell signaling include reception, transduction, and response. Reception is when a signal molecule
(ligand) binds to the receptor protein on the outside of a target cell. Next, transduction (a series of events involving secondary messengers) occurs as the
binding of the ligand causes a change in the receptor protein, which then brings about a specific cellular response. If there is a change in the signal
transduction pathway, this can ultimately alter the cellular response, as the pathway in which the message is being carried along and amplified, controls
whether or not the response occurs. Transduction occurs as a series of events, but it can also occur as a series of unfortunate events. Examples based on
scientific evidence where pathways may be interrupted or altered include drugs, poisons, or diseases in the body. Poisons, such as those found in anthrax
can cause a disruption in signal transduction pathways. Normally, a ligand would bind to a G-protein which then releases an alpha subunit that creates
cAMP, which is a secondary messenger that amplifies the message and targets different parts within the cell. But when the poison that is found in
anthrax is present, it targets the enzyme adenylate cyclase thus changing it’s shape, making it not able to convert ATP to cAMP. As a result, the signal
transduction pathway is disrupted and the cellular response is altered. Another example is diabetes. Diabetes is a disease in which the body has shortage
of insulin, a decreased ability to use insulin, or both. Insulin is a hormone that allows glucose to enter cells and be converted to energy. In each of our
bodies there is an insulin receptor that sits on the surface of specific target cells. Once insulin binds to that receptor, a series of events occurs within the
cell including an effect on the glucose transporter (GLUT) which allows the cell to take in glucose to make use of it by storing it as glycogen. With Type 1
Diabetes, a person is not producing insulin, therefore it doesn’t have the capabilities of binding with the receptor. With Type 2 Diabetes, the insulin
receptor is ignoring the message that is trying to come through ultimately disrupting the signal transduction pathway by inactivating GLUT and as a result
the person doesn’t take in glucose.
MC Question:
If the insulin receptor located on a target
cell was to become inhibited, what would
most likely be the result of this disruption?
(Look at diagram to the right)
a) Insulin would still bind to the receptor
protein but no message would be
relayed.
b) Insulin would diffuse through the cell
membrane and target an intracellular
receptor that was active.
c) The amount of glucose would increase.
d) The cells would eventually die due to the
fact that there was no cellular activity
(cell communication) taking place
because the receptors were inhibited.
Free response: A group of scientists are designing an experiment in which they are trying to
figure out how to inhibit a disruption in the signal transduction pathway via cell
communication.
a) Describe the process that occurs during normal cell communication
b) Discuss one thing that could help the inhibition of these pathways
c) Provide evidence of a real life disease that results in a disruption to these pathways
MC Question:
If the insulin receptor located on a target cell was to become inhibited, what would most likely be
the result of this disruption?
a) Insulin would still bind to the receptor protein and a message would be relayed.
b) Insulin would diffuse through the cell membrane and target an intracellular receptor that was
active.
c) The amount of glucose would increase.
d) The cells would eventually die due to the fact that there was no cellular activity (cell
communication) taking place because the receptors were inhibited.
A is not correct because if insulin were to bind to a receptor that is inhibited then the message would not be
relayed. B is not correct because insulin can’t diffuse through a cell because it is a protein (hormone) and it
would be too big to pass through. D is not correct because cells don’t die because there isn’t any cellular
activity, they die from programmed cell death or exposure to harmful environments. C is the answer because
since the receptors are inhibited, insulin can’t bind which then can’t open the glucose transporter (GLUT) so
the amount of glucose levels would increase since glucose can’t be taken into the cell for storage as glycogen.
Free response: A group of scientists are designing an experiment in which they are trying to figure
out how to inhibit a disruption in the signal transduction pathway via cell communication.
a) Describe the process that occurs during normal cell communication
b) Discuss one thing that could help the inhibition of these pathways
c) Provide evidence of a real life disease that results in disruption to these pathways
Cell communication can occur through short or long distances. Cell communication starts out with reception when a ligand
binds to a receptor, then transduction when the message is being amplified through a series of steps with the use of
secondary messengers, and it finally results in a cellular response. One way that the scientists could inhibit this disruption is
to inhibit the receptor in which the ligand binds to. If that is inhibited then no message can be relayed causing no disruption
in the signal transduction pathway, also creating no cellular response. A real life disease in which this occurs is diabetes.
With Type 1 Diabetes, a person is not producing insulin, therefore it doesn’t have the capabilities of binding with the
receptor. With Type 2 Diabetes, the insulin receptor is ignoring the message that is trying to come through ultimately
disrupting the signal transduction pathway by inactivating GLUT and as a result the person doesn’t take in glucose.
LO 4.24: The student is able to predict the effects of a change in an environmental factor on the
genotypic expression of the phenotype
SP 6.4: The student can make claims and predictions about natural phenomena based on scientific
theories and models
Explanation: Different environmental stimuli will turn genes on or off in the processes of gene
regulation and expression. These stimuli include changes in temperature, light (UV radiation),
drugs, chemicals and pH. A gene for increased growth in animals could be turned on because of
one of these stimuli. A specific example could be presence of the opposite mating type on
pheromones production in yeast and other fungi or an environmental factor determining the sex
of a reptile.
M.C. Question: Hydrangeas were planted in the spring and bloomed pink, however the flowers later
turned blue in the late summer/early fall. Which of the following best accounts for this change in
color?
A) The higher UV index denatures the color pigments in the petals and changes them from pink to
blue.
B) A change to the color blue serves as a defense mechanism from harmful parasites that come out
during warmer seasons.
C)The pH of the soil fluctuated, causing a gene in the plant that makes it blue to be turned on and
expressed
D)The roots of the plant become more selective during different seasons and the nutrients that are
selected for during the summer change the blossom color to blue.
Learning log/FRQ style Question:
i. Briefly define the process of gene regulation and gene
expression AND
ii. Relate how a change in season could impact
gene expression and the phenotype of an arctic fox.
iii.Relate how removing lactose from a bacterial culture
of E. coli affect the genome and phenotypic expression?
Answer Key-LO 4.24
Hydrangeas were planted in the spring and bloomed pink, however the flowers later turned blue in the late
summer/early fall. Which of the following best accounts for this change in color?
A) The higher UV index denatures the color pigments in the petals and changes them from pink to blue.
B) A change to the color blue serves as a defense mechanism from harmful parasites that come out during warmer
seasons.
C)The pH of the soil fluctuated, causing a gene in the plant that makes it blue to be turned on and expressed
D)The roots of the plant become more selective during different seasons and the nutrients that are selected for
during the summer change the blossom color to blue.
Answer C is the only choice that makes sense because a color change in a flower is from a gene being activated or
deactivated and this affects the phenotype of the flower. The rest of the answer choices do not involve an
environmental factor changes gene expression and regulation.
i. Define the process of gene regulation and gene expression AND
ii. relate how a change in season could impact gene expression and the phenotype of an arctic fox.
iii. Relate how removing lactose from a bacterial culture of E. coli affect the genome and phenotypic expression.
i. Gene regulation is the process of turning genes on and off to ensure they are expressed at the proper time. Also
gene regulation can help an organism respond to its environment. Gene expression refers to whether a gene is
activated and being used or not and if it is, the genotype and phenotype reflects it. In order to do this in
eukaryotes, a gene must undergo transcription into RNA, which is then processed into mRNA and transported
to the cytoplasm. Here, some mRNA is degraded but some is translated to a polypeptide. The polypeptide
then may be cleaved or chemically modified to form an active protein which might denature and transform
into a degraded protein.
ii. During the winter, the fur coat of the arctic fox usually lightens due to a decrease in the amount of daylight.
This lack of daylight causes a genetic change in the animal and the fur to lighten.
iii. When genes in the lac operon are transcribed, a single mRNA is produced. In the absence of lactose, the
operon is turned off. The regulatory gene lacI produces an mRNA that produces a lac repressor protein, which
can bind to the operator of the lac operon. The lac regulatory protein is called a repressor because it keeps
RNA polymerase from transcribing the structural genes. It would be inefficient for e. coli to express lac genes
with no lactose present which is why the lac repressor prevents transcription of the gene.
How genes can be turned on (above)
Various levels of
gene expression
and regulation
(left)
LO 2.30 The student can create representations or models to describe nonspecific immune defenses in plants and animals.[See SP 1.1, 1.2]
SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain.
SP 1.2 The student can describe representations and models of natural or man-made phenomena and systems in the domain.
Explanation: A nonspecific immune responses can be defined as the generalized line of defense which an organism innately has.
These nonspecific responses attempt to fend off all prospective threats to the organism, hence the “nonspecific.” Invertebrates are limited to these
nonspecific mechanisms, lacking the secondary line of defense which are pathogen specific in vertebrates. Nonspecific defenses include but are not
limited to: barriers (skin), phagocytosis, elimination, unfavorable pH/environments, systematic cell destruction, lysozyme action, the inflammatory
response and traps (mucus membranes). Plant defenses are also limited to nonspecific responses which overlap with animals. Plant defenses
against pathogens include molecular recognition systems with systemic responses; infection triggers chemical responses that destroy infected and
adjacent cells, thus localizing the effects and removing anything that could be afflicted. Students should fully grasp these concepts, and in turn, be
able to produce visual representations or models of the nonspecific immune processes.
M.C Question:
Which of the following isn’t an innate immunity that protects an individual as they are riding the subway from contracting a bacterial infection?
a.) Natural killer cells b.) skin c.) memory B cells d.) mucous membranes
Learning Log Question: Plants and animals have myriad nonspecific immune responses that are the first line of defense for organisms.
a.) Discuss three nonspecific immune system responses that hinder the establishment of a pathogen within the body. Provide a diagram to support
your response with at least one of the nonspecific responses you explain.
b.) Plants only have a nonspecific immune responses. Discuss an immune defense mechanisms of a plant and provide a diagram to illustrate this
process.
Skin: our body’s barrier and primary defense mechanism
Answer Key
M.C Question:
•
Which of the following isn’t an innate immunity that protects an individual as they are riding the subway from contracting a bacterial
infection?
a.) Natural killer cells b.) skin c.) memory B cells d.) mucous membranes
•
All of the choices above are nonspecific immune defensives , with the exception of C. Memory B cells are specific to antigens that infect
our bodies; they “remember” how to fend off the infection so that our bodies won’t have to fight the same infection twice. (The reason
we only get the chicken poxs once)
Learning log Question: Plants and animals have myriad nonspecific immune responses that are the first line of defense for organisms.
a.) Discuss three nonspecific immune system responses that hinder the establishment of a pathogen within the body. Provide a diagram to
support your response with at least one of the nonspecific responses you explain.
Sample response A: Our skin acts as a defensive barrier to bacteria and viruses in the environment; it prevents bacteria from reaching inner
cells that which would suffer if otherwise breeched. The opening of our bodies are protected by traps such as ear wax, hair or mucus
membranes which essentially “catch” pathogens as they attempt to enter the body. Mucus membranes contain pathogen destroying enzymes
which kill pathogens, further shielding the body from infection. The inflammatory response is induced in situations when the body becomes
vulnerable- for instance, paper cuts. Cells of the afflicted area send out histamines, attracting macrophages. Vasodilation occurs, increasing
blood flow to the area in order for more macrophages to inhibit and engulf pathogens.
•
Other responses could reference: Phagocytosis (white blood cells), Elimination (coughing, sneezing, urination) Unfavorable pH
/environment (stomach acid, sweat, saliva, urine), Cellular destruction (i.e natural killer cells, complement), Interference with viral
replication (interferon), Lysozyme action (excretion of sweat/ tears)
Diagram of Inflammatory Response
Answer Key Continued
LL Question Part B:
b.) Plants only have a nonspecific immune responses. Discuss an immune defense mechanism of
a plant .
Sample Response B: Plants nonspecific response to pathogens include the Hypersensitive
Response (HR). Essentially, HR is a form of apoptosis or programmed cell death. If the plant cells
are presented with some sort of foreign cell, then the afflicted cells breakdown along with those
adjacent to them to minimize the prospective diseased area and preventing the spread of
microbial pathogens.
LO 1.17: The student is able to pose scientific questions about a group of organisms whose relatedness is
described by a phylogenetic tree or cladogram in order to (1) identify shared characteristics, (2) make inferences
about the evolutionary history of the group, and (3) identify character data that could extend or improve the
phylogenetic tree.
SP 3.1: The student can pose scientific questions.
Explanation: Due to evolution, organisms share many common biological processes that are necessary for
survival. The presence of these common processes serves as evidence that all organisms are linked to some kind
of common ancestry. Phylogenetic trees show evolutionary history, representing both acquired traits and traits
lost during evolution by means of natural selection. Phylogenetic trees and cladograms model speciation that has
ANSWER KEY– LO 1.17
M.C.
The following cladogram shows the distribution of five different derived characteristics in six different species.
The cladogram can provide insight into vertebrate phylogeny for all of the posed questions EXCEPT:
A. Why do all the vertebrates in the ingroup have backbones?
Incorrect– The cladogram shows that all of the vertebrates in the ingroup have backbones. This is because it is
a shared primitive character that was present in the ancestral vertebrate, though not in the outgroup.
B. Why are hinged jaws a character absent in lampreys but present in other members of the ingroup?
Incorrect– The cladogram shows that lampreys do not have this character; this character is the early branch point in the vertebrate clade.
C. What is the evolutionary history of each of the species?
Correct– A cladogram is not a phylogenetic tree and cannot show this information. Phylogenetic trees depict hypotheses about evolutionary
relation while cladograms only show patterns of shared characteristics. To covert this cladogram into a phylogenetic tree would require more
information from fossils, for example.
D. Why is lancelet considered as part of the outgroup?
Incorrect– The cladogram shows that the lancelet less closely related than any of the ingroup members are to each otherirtually no shared
characteristics.
FRQ: You are attempting to convert this cladogram into a phylogenetic tree. Answer the following questions to serve as the premise for your
research: (a) How do you identify organisms with shared characteristics on a cladogram? (b) What inference can be drawn about the evolutionary
history of the group? (c) What character data could be used to help convert the cladogram into phylogenetic tree? Identify at least two
mechanisms.
(a) A cladogram will begin by grouping organisms based on a characteristics displayed by ALL the members of the group. Subsequently, the
larger group will contain increasingly smaller groups that share the traits of the groups before them.
(b) The hinged jaw character absent in lampreys is present in other members of the ingroup; this character helps us identify an early branch
point in the vertebrate clade. This provides evidence of the possible evolution of a new species.
(c) To convert this cladogram into a phylogenetic tree we would need more information-for example, from fossils, which can indicate when,
and in which groups, the characters first appeared. Identifying more branching points by extending the pool of organisms would broaden the
scope of the phylogenetic tree and allow for more accurate history of the evolution of the species.
A. LO 3.16: The student is able to explain how the inheritance patterns of
many traits cannot be accounted for by Mendelian genetics.
B. SP 6.3: The student can articulate the reasons that scientific explanations
and theories are refined or replaced.
C. Mendelian genetics occur when the offspring follows the predictable
pattern of a 3:1 phenotypic ratio and 1:2:1 genotypic ratio. But,
epigenetic inheritance, polygenetic inheritance, and many other variables
can interrupt the Mendelian inheritance patterns.
D. Which is an example of non-Mendelian inheritance?
a. hitchhiker’s thumb
c. widow’s peak
b. skin color
d. earlobe detachment
E. Mendelian inheritance with non-Mendelian inheritance have several
differences.
a) List and explain three facets of Mendelian genetics.
b) List and explain three facets of non-Mendelian genetics.
D. The answer is “B” because skin color is an example of polygenetic
inheritance, but the other traits are distributed through Mendelian genetics.
E. a) Mendel has three laws, which involve segregation, dominance, and
independent assortment. Segregation is when chromosome pairs are
separated into individual gametes to carry genetic information to their
offspring. Dominant and recessive alleles are also important parts of Mendel
genetics because dominant alleles cancel out the affect of recessive alleles.
Independent assortment is when alleles on different chromosomes are
distributed randomly to individual gametes.
b) Polygenetic traits are determined by the combined effect of more than one
pairs of genes. Co-dominance is when the two alleles are both expressed in a
heterozygote, instead of a recessive allele’s expression being blocked.
Pleiotropy occurs when a single gene is responsible for more than one trait,
like in sickle cell anemia and albinism.
LO 1.4 The student is able to evaluate data-based evidence that describes evolutionary changes in the genetic makeup of a population over time.
SP 5.3 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively .
Explanation: According to Darwin’s theory of natural selection, competition for limited resources results in differential
survival. Individuals with more favorable phenotypes are more likely to survive and produce more offspring, thus passing
traits to subsequent generations. Although natural selection is usually the major mechanism for evolution, genetic
variation in populations can occur through other processes, including mutation, genetic drift, sexual selection and
artificial selection. Inbreeding, small population size, nonrandom mating, the absence of migration and a net lack of
mutation can lead to a loss of genetic diversity. Using evidence given from a diagram or chart, students should be able
to describe what changes caused the differences in the genetic make up of a population.
Cross 2
Learning Log/FRQ-style Question: A new species of fly
was discovered in the South Pacific. Several different
crosses were performed, each using 100 females and
100 males. The phenotypes of the parents and the
resulting offspring were recorded.
Cross I. All F1 offspring had bronze eyes. F1 flies were
crossed, and the data for F2 flies are given below.
Cross II: All F1 offspring had stunted wings. F1 flies were
crossed, and the data for F2 flies are shown to the right.
Cross III: All F1 offspring had bronze eyes and stunted
wings. F1 flies were crossed with true-breeding red-eyed,
normal-winged flies, and results are shown to the right.
Based on the information given in the charts above, what
conclusions can be draw from cross I and II? What data
can then be drawn from Cross III? Explain how the data
supports your conclusion
Cross 1
F2
Phenotype
Male
Female
Bronze
eyes
4,720
4,800
Red eyes
2,260
2,320
F2
Phenotype
Male
Female
Normal
wings
2,160
2,320
Stunted
wings
4,600
4,820
Cross 3
Phenotype
Male
Female
Bronze eyes,
stunted wings
3,360
3,220
Bronze eyes, normal
wings
320
400
Red eyes, stunted
eyes
360
320
Red eyes, normal
wings
3,240
3,180
M.C. Question: Using the charts above and to the left, which of the
following factors would affect whether the island’s fly population is in
Hardy-Weinberg equilibrium for the gene above?
A) There is a large population size so it maximizes genetic drift
B) Random mating causes gene pool changes due to mate preferences.
C) There are no mutations meaning that there are no new alleles in the
population.
D) There is no immigration but there are gene pool changes caused by
the addition and subtraction of alleles.
E) There is no natural selection even though there are alleles favored
or disfavored by the environment.
Answer Key – LO 1.4
M.C. Question: Using the charts above and to the left, which of the following factors would
affect whether the island’s fly population is in Hardy-Weinberg equilibrium for the gene
above?
A) There is a large population size so it maximizes genetic drift
B) Random mating causes gene pool changes due to mate preferences.
C) There are no mutations meaning that there are no new alleles in the population.
D) There is no immigration but there are gene pool changes caused by the addition and
subtraction of alleles.
E) There is no natural selection even though there are alleles favored or disfavored by the
environment.
FRQ Answer: For cross I, bronze is dominant and red is recessive, and non-sexlinked are also autosomal. All F1 or heterozygotes express dominant traits such
as the bronze flies. The F2 generation shows a 3 to 1 ratio. There is an equal
distribution of F2 phenotypes for both genders. For cross 2, the stunted is
dominant and the normal is recessive, and the non-sex-linked are also
autosomal. All F1 heterozygotes express dominant traits because they are
stunted, and F2 shows a 3 to 1 ratio. There is also an equal distribution of F2
phenotypes for both genders. For cross 3, the genes are linked, there is crossing
over, and genes are 10 map units apart. That is due to how there is not a 1:1:1:1
ratio as predicted by independent assortment. There is also not a 1:1 ratio or two
recombinant phenotypes that are unexpected. The frequency of recombinant
phenotypes was also 10%.
LO 2.25 The student can construct explanations based on scientific evidence that homeostatic mechanisms reflect continuity due to common ancestry and/or
divergence due to adaptation in different environments
SP 6.2 The student can construct explanations of phenomena based on evidence produced through scientific practices.
Explanation: A Homeostatic mechanism is the property of a system in which variables are regulated so that internal conditions remain
stable and relatively constant. In other words homeostasis is an internal stable environment. Many organisms have similar mechanisms
to restore homeostasis against certain factors such as dehydration. A disrupted environment due to natural disasters such as a drought or
water limitation, can cause the organism to be faced with a lack of water resources in the environment. The excretory system tries
conserve the water already retained by minimizing the water loss through urine and sweat glands and releasing anti-diuretic hormones.
Also most animals respond in a similar way towards fighting infection through the action of the immune system such as signaling the
white blood cells (B and T cells) to fight pathogens and kill infected cells. When we look at a variety of organisms and how they maintain
homeostasis we discover a continuity or a simple strategy once developed, which run through an entire lineage or ancestry. Change can
result from different environmental factors being pressured onto the organism living in the new environment. In 2004 the Tiktaalik
experiment conducted by Neil Shubin proved that the Tiktaalik (an extinct four legged organism that had gills to swim in water, lungs to
breathe on land, 4 fins/leg to live on land and swim in the water) stood as a representative of the evolutionary transition from fish to
amphibians. This was due to a change to adapt to different environments. Tiktaalik was an important transitional fossil that enabled us to
understand how different environmental pressures result in certain characteristics to become favored over time. Although certain
systems, such as the excretory system (used for getting rid of waste and blood filtration) in earthworms, vertebrates, and flatworms
serve the same purpose and remain unchanged over the last millions of years resulting in continuity.
M.C. Question: Which of the following statements below is FALSE concerning the scientific evidence of homeostatic mechanisms
with regards to EVOLUTION in the excretory system?
A) Invertebrates and vertebrates both evolved to having an excretory system extremely similar to each other in the function of
getting rid of excess solutes or water due to sharing a common ancestor
B) Excretion can vary greatly between invertebrates and vertebrates, depending on the complexity of the organism.
C) An organisms morphology is developed through specialized structures that makeup the excretory system
D) Osmoregulation (control of levels of water and mineral salts in blood) in the excretory system required no evolution
Amphibian
Learning Log/FRQ-style Question:
Consider the situation of a marine
organism obtaining oxygen from the
water and into animal cells, to
transitioning to a terrestrial organism
obtaining oxygen through the air and
into animal cells. Through this
evolutionary process, what adaptations
would be favored by natural selection?
Tiktaalik
Fish
Answer Key- LO 2.25
M.C. Question: Which of the following statements below is FALSE concerning the scientific evidence of homeostatic mechanisms with
regards to EVOLUTION in the excretory system?
A) Invertebrates and vertebrates both evolved to having an excretory system extremely similar to each other in the function of getting
rid of excess solutes or water due to sharing a common ancestor
B) Excretion can vary greatly between invertebrates and vertebrates, depending on the complexity of the organism.
C) An organisms morphology is developed through specialized structures that makeup the excretory system
D) Osmoregulation (control of levels of water and mineral salts in blood) in the excretory system required no
evolution
M.C. Question Answer: The correct answer for this question was D due to the
fact that osmoregulation did require evolution. There is scientific evidence that
Cetaceans had to adapt to new environmental changes by maintaining their salt
and water balance to survive. This also suggests that cetaceans may have
evolved an effective and complex mechanism for osmoregulation used today in
organisms.
Learning Log/FRQ-style Question: Consider the situation of a marine organism obtaining oxygen from the water
and into animal cells, to transitioning to a terrestrial organism obtaining oxygen through the air and into animal
cells. Through this evolutionary process, what adaptations would be favored by natural selection?
Learning Log/FRQ-style Answer: (Each explanation for a favored adaptation
is a point, 3 points max.) Adaptations favored would include tissues of the
respiration system to adapt from a wet/moist environment to a dry
environment. Also tissues must be adapted to going from an environment of
low oxygen levels in the water to an environment of high oxygen levels on
land. Another adaptation would include a change in homeostatic
mechanisms going from gills in species such as fish processing oxygen
through counter current exchange to developing lungs in species such as
mice to maintain water levels.
LO 2.23: The student is able to design a plan for collecting data to show that all biological systems (cells, organism, populations, communities and ecosystems) are affected by complex biotic
and abiotic interactions.
SP 4.2: The student can design a plan for collecting data to answer a particular scientific question.
SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring understandings and/or big ideas.
Explanation: All biological systems, from cells to ecosystems, are influenced by complex biotic and abiotic interactions. The availability of resources
influences activities in cells and organisms; examples include responses to cell density, biofilm(s) formation, temperature responses, and responses
to nutrient and water availability. Cell activities are affected by interactions with biotic and abiotic factors; high temperatures denature important
proteins in cells disrupting its activity. The activity of organisms can also be influenced by biotic and abiotic factors, these influences can be observed
with symbiosis, predator-prey relationships and how these organisms react to environmental changes such as temperature, water and nutrient
availability and pH. Water and nutrient availability affect the primary producers and this in turn disrupts food chains and food webs that affect the
stability of populations, communities and ecosystems. To collect data to show how biological systems are affected by complex biotic and abiotic
interactions one could design an experiment or conduct an observational study. The scientific method should be used for an effective experiment,
the steps of the scientific method are: the formulation of a question, make a hypothesis, experiment, and analyse the data. The information is
collected in the experiment (testing) part of the scientific method. After the collected data is analyzed, the problem in question is answered.
M.C. Question:
Which of the following is NOT a cell's response to high
temperatures?
A. Proteins denature.
B. Kinetic energy of the cell decreases.
C. The phospholipid bilayer behaves like a liquid.
D. Respiration rates increase.
Learning Log/ FRQ-style Question:
Figure 1 illustrates the symbiotic mutualistic relationship between the
clownfish and sea anemone. The clownfish’s fecal matter provides
nutrients to the sea anemone while the clownfish feeds on small
invertebrates that could harm the sea anemone it also protects it from
predators with its stinging cells to which the clownfish is immune to.
a. Design an experiment whose outcome would support
the idea that the mutualistic relationship is beneficial for
both animals.
Figure 1 source: http://en.wikipedia.org/wiki/File:Common_clownfish_curves_dnsmpl.jpg
Figure 1
Answer Key- LO 2.23
M.C. Answer:
Which of the following is NOT a cell's response to high
temperatures?
A. Proteins denature.
B. Kinetic energy of the cell decreases.
C. The phospholipid bilayer behaves like a liquid.
D. Respiration rates increase.
Learning Log/ FRQ-style Question:
Figure 1 illustrates the symbiotic mutualistic relationship between the
clownfish and sea anemone. The clownfish’s fecal matter provides
nutrients to the sea anemone while the clownfish feeds on small
invertebrates that could harm the sea anemone it also protects it from
predators with its stinging cells to which the clownfish is immune to.
Design an experiment whose outcome would support the idea that the
mutualistic relationship is beneficial for both animals.
Learning Log/ FRQ-style Answer:
a. Experiment;
-Question: Is symbiotic mutualistic relationships actually beneficial for both
organisms?
-Hypothesis: If symbiotic mutualistic relationships benefit both organisms,
then when separated, the organisms would have lower survival rates.
-Test: Have three separate tanks modeling coral reefs where clownfish and
sea anemones usually live. One (the control group) would have a normal coral
reef model with the clownfish and the sea anemone living together. The
second model would have a regular coral reef with clownfish but no sea
anemone and the third model will be a regular coral reef with sea anemones
but not clownfish. Leave the three models alone, untouched for a month so
they model a real coral reef and after the month has passed calculate the
survival rate of each organism.
*Independent variable: Whether or not the two organisms are together
*Dependent variable: Survival rate
-Collect and record data
-Reach a conclusion
LO 3.30 - The student is able to use representations and appropriate models to describe how viral replication
introduces genetic variation in the viral population.
SP 1.4 – The student can use representations and models to analyze situations or to solve problems
quantitatively and qualitatively.
Explanation – Viruses have great genetic variation when a single species of virus is compared with the rest of its
population. First off viruses can replicate efficiently and at an incredibly high rate which makes the RNA coding
errors that already have a high rate of occurrence because of a lack of replication error-checking mechanisms
happen more frequently. Viruses also increase their replication rate by simply replication using a component
assembly model (lytic cycle) which allows for one virus to make plenty of offspring with just itself and a host
organism.
M.C. Question
Which stage is the selection point for the
virus to choose between the lytic cycle or the
lysogenic cycle?
A: E
B: B
C: C
D: D
Free Response Question
The graph to the right is the population of a
bacteria in a given area and time. In section
C a virus is introduced into the bacteria’s
environment. Predict what will happen to
the population of the bacteria after the virus
is introduced.
Answers to LO 3.30
M.C. Question
Which stage is the selection point for the virus to choose between the lytic cycle or
the lysogenic cycle?
A: E
B: B
C: C
D: D
Free Response Question
The graph to the right is the population of a bacteria
in a given area and time. In section C a virus is
introduced into the bacteria’s environment. Predict
what will happen to the population of the bacteria
after the virus is introduced.
Answer
The Bacteria will likely follow suit with the new
graph to the right. This is because the rapid amount
of reproduction of the virus causes the bacteria
population to plummet. The reproductive method
kills the host bacteria so the large amount of viruses
made after the plummet will not be able to find
bacteria to infect. After a certain amount of time
both the viruses and the bacteria hit their carrying
capacity.
Learning Concept 3.27 : The student is able to compare and contrast processes by which genetic variation is produced and maintained in
organisms from multiple domains
Science Practice 7.2 : The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or
across enduring understandings and/or big idea.
Explanation: One reason that genetic variation is produced and maintained in organisms from multiple domains is because of the
imperfect nature of DNA in the process of replicating and repairing. Usually an error in DNA occurs in one base pair for every one
billion base pairs per replication cycle but the numbers add up quickly. What stops DNA polymerase, which reads from the 3’ -> 5’ end
of the DNA strand, from creating more mutations in the DNA replication process is its ability to proofread information. There can also
be a repair mishap where the Base-pair or Short-patch excision repair don’t occur correctly.
Another reason that organisms from multiple domains have genetic variation is because of horizontal acquisitions of genetic
information, usually in prokaryotes, through transformation, transduction, conjugation and transposition. Transformation is when a
prokaryote uptakes naked DNA and incorporates it into its own DNA, transduction is when a virus injects genetic information from its
previous host and transfers it to a new cell to which it injects its viral and previous host cell information into the new cell, conjugation
is when two cells create a mating bridge and the replication of a plasmid occurs and is delivered to the recipient cell from the donor
cell, and transposition is the movement of DNA around the chromosomes from one gene to another part of the genome through the
function of transposable elements.
Eukaryotes maintain their genetic variation through gamete formation. This includes crossing over which occurs in Prophase 1 where
homologous chromosomes line up, cross a section of their chromatid and exchange portions of DNA, Independent assortment results
from Anaphase 1 when the homologous chromosomes separate due to the contraction of spindles, and fertilization serves to increase
variation because the mothers egg is a haploid, has half of the genetic information, and the sperm has the other half of the genetic
variation.
Multiple Choice: Which of the following is the least likely to
contribute to genetic diversity in Eukaryotic cells.
A. Crossing Over in Prophase 1 of meiosis
B. The fertilization of the ovum by a gamete creating a zygote.
C. Conjugation caused by a mating bridge forming and the
donor cell transferring plasmid information to the recipient cell
D.DNA polymerase adding the wrong base pairs to DNA during
replication or repair of a DNA strand
FRQ: Genetic variation is maintained by prokaryotic cells
even though they do not undergo basic gamete formation
like their Eukaryotic counterparts. Describe how
conjugation in prokaryotic cells can increase their genetic
variation. Draw a diagram and label the steps that you
described in your description.
Multiple Choice: Which of the following is the least likely to
contribute to genetic diversity in Eukaryotic cells.
A. Crossing Over in Prophase 1 of meiosis
B. The fertilization of the ovum by a gamete creating a zygote.
C. Conjugation caused by a mating bridge forming and the
donor cell transferring plasmid information to the recipient
cell
D.DNA polymerase adding the wrong base pairs to DNA during
replication or repair of a DNA strand
FRQ: Genetic variation is maintained by prokaryotic cells even
though they do not undergo basic gamete formation like their
Eukaryotic counterparts. Describe how conjugation in
prokaryotic cells can increase their genetic variation. Draw a
diagram and label the steps that you described in your
description. Also add an example of how conjugation could be
used in scientific research.
FRQ Answer: In the first part of conjugation there is an F+
plasmid cell, which will be the donor cell, and the F- cell, which
is the recipient cell. The F+ cell has a pilus and it attaches it to
the F- cell to create a mating bridge. Then the plasmid from the
F+ cell is replicated and sent across the mating bridge. After the
replication is complete, although the mating bridge usually
breaks before the full replication of the plasmid, the donor
plasmid will then be in the recipient cell and the connection
between the cells is broken. This will then create to two F+ cells
because both will have a plasmid. Now the previous recipient
cell is now capable of transferring the plasmid DNA to other
recipient cells. Conjugation can be used in research by having
cells with plasmids donate their antibody resistant genes to
other cells so that only the cells with the antibody resistant gene
will survive in a petri dish with a petri dish with the antibody.
Picture Source:
http://academic.pgcc.edu/~kroberts/Lecture/Chapter%207/horizontal.html
Multiple Choice Explanation:
A. Crossing over increases genetic diversity in Eukaryotic cells by having Nonsister chromatids from homologous chromosomes exchange genetic information.
This allows the combination of alleles form all the genes on the chromosome
changes every generation.
B. Fertilization occurs after meiosis where genetically varied gametes have half the
chromosomes as the parent organism. When fertilization occurs, a random
sperm and egg will fuse and create a zygote with the same number of
chromosomes as the parent organisms. The resulting organism is a variation of
the parental egg and sperm combination.
C. Conjugation is most common in prokaryotic cells. This happens when a mating
bridge is created between to cells and then the donor cells replicates its plasmid
DNA and transfers it toe the recipient cell where crossing over can take place
with the recipient cells DNA and the donor’s plasmid.
D. Usually an error in DNA occurs in one base pair for every one billion base pairs
per replication cycle but the numbers add up quickly. Although this number
does not seem like a lot, there are 1 base pair mutation in one billion base pairs
per replication cycle. Although this doesn’t sound like many mistakes, the
numbers do accumulate at a very high rate.
Sample Drawing
LO 1.5: The student is able to connect evolutionary changes in a population over time to a change in the
environment.
SP 7.1: The student can connect phenomena and models across spatial and temporal scales.
Explanation: Evolution, the heritable change in organisms over time, can be altered by factors in its environment. Such
factors include human impact, change in food source, change in climate, increase/decrease of competition,
immigration/emigration of species in the organisms community, habitat loss, and the availability of resources. These
increase the inherent variation in a species by reproduction among the best suited organisms for its environment. For
example, when the pollution from the industrial revolution in England caused a change in environment (which acts as a
selective mechanism on the moths) of the bark on many trees to turn black, many of the light colored peppered moths
began to die from predation. A random change in DNA, called a mutation, caused one of these moths to turn black,
camouflaging it with the trees. The phenotypic variation was a benefit, so the moth lived to reproduce, creating more of
these black moths. The black moths were favored in their environment, evolution occurred, and the black peppered moths
became the most abundant. Humans impacted variation in the moths because they created the pollution.
M.C. Question: A community of giraffes living in Africa were dying off because the trees in their environment were
growing taller. The giraffes could not reach the leaves, which were their only source of food. Then a giraffe was born
with a change in DNA that caused the giraffe to have a longer neck that could reach the higher trees. What would
most likely occur due to this mutation?
a.
b.
c.
d.
e.
The normal neck length giraffes would kill the long neck one, due to the increased competition
The giraffe would be more likely to live to reproduce, and over time the beneficial “long neck trait” would evolve into the population
The trait is not beneficial, therefore future possible offspring would not inherit the trait
All the giraffes would acquire this trait without inheritance
The long neck giraffe would be more likely to reproduce, but
mutations are not able to be inherited by offspring
Learning Log/FRQ-style Question: Use Figure 1.
a. Describe an environment that pointed beak finches would
be favored and an environment blunt beak finches would be
favored.
b. Describe how the finches evolved.
c. Explain a reason the favored trait could change in a
population of finches from blunt to pointed and back to blunt.
Figure 1
ANSWER KEY– LO 1.5
MC Answer: A community of giraffes living in Africa were dying off because the trees in their
environment were growing taller. The giraffes could not reach the leaves, which were their only
source of food. Then a giraffe was born with a change in DNA that caused the giraffe to have a
longer neck that could reach the higher trees. What would most likely occur due to this
mutation?
a.
b.
c.
d.
e.
The normal neck length giraffes would kill the long neck one, due to the increased competition
The giraffe would be more likely to live to reproduce, and over time the beneficial “long neck trait” would
evolve into the population
The trait is not beneficial, therefore future possible offspring would not inherit the trait
All the giraffes would acquire this trait without inheritance
The long neck giraffe would be more likely to reproduce, but mutations are not able to be inherited by offspring
FRQ Response:
a. Pointed beaks would be favored in an environment of finches that eat insects. The pointed beak would
give them the ability to “spear” the insect. Blunt beaks would be favored in an environment of finches that
eat seeds from the ground. The stronger blunt beak would give them the ability to peck seeds open.
b. The finches evolved due to a mutation in its DNA . This mutation made the finch more likely to survive,
giving it a greater chance to be able to reproduce. This phenomena is known as reproduction of the fittest.
Once the mutated finch reproduced, more finches would have the favored trait, and they would also have a
greater chance of reproducing. Over time, the favored trait will be present in most of the species through
evolution.
c. If most of the finches on one of the Galapagos Islands had blunt beaks and a drought occurred, the seeds
they eat would be less available. The finches would start eating insects and a long beak would be favored.
Then if a new predator of the insects was introduced into the environment and the drought had ended, the
finches would switch back to eating seeds because there would be less competition. The blunt beak would
then be favored again.
LO 2.29: The student can create representations and models to describe immune responses
SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain
SP 1.2: The student can describe representations and models of natural or man-mad phenomena and systems in the domain.
Explanation: There are several nonspecific immune responses in plants, invertebrates and vertebrates. When pathogens attack plant cells, a
chemical response is triggered that destroys the infected and adjacent cells. Invertebrates do not have a pathogen-specific defense response,
while vertebrates have non-heritable defense mechanisms against pathogens. Mammals respond to homeostasis disruptions with a specific
immune response. This can either be a cell mediated or humoral immune response. In a cell-mediated response, cytotoxic T cells target
pathogens after the antigen binds to the pathogen. In the humoral response, B cells secrete antibodies to target specific antigens. Memory cells
are a product of the humoral response, therefore making the immune response respond more quickly and rapidly at the second detection of the
same antigen. Mammalians also have nonspecific defense mechanisms. The first line of defense are barriers such as skin and the mucous
membranes to keep pathogens from entering the body. When microbes enter the body, then the second line of defense helps limit the spread
of pathogens. This includes an inflammatory response, phagocytes that ingest microbes, and natural killer cells that causes target cells to lyse.
Multiple choice question: Which of the following shows the correct humoral immune response after the body is exposed to an antigen?
I. Plasma and memory B cells are cloned
II. The helper T cells are activated by the presence of a macrophage
III. A macrophage deteriorates the specific antigen by engulfing it
IV. Antibodies are secreted
V. A production of cytokines
A.) I, II, III, IV, V
B.) III, II, V, I, IV
C.) IV, V, I, III, II
D.) V, II, III, I, IV
Learning Log/FRQ: A macrophage is a type of phagocyte and it
plays a role in both non-specific and specific defense mechanisms.
Phagocytosis is a mechanism that occurs to remove pathogens.
Draw and label a macrophage using the following terms:
bacterium, lysosome, vacuole, pseudopodia, debris, exocytosis,
and receptors.
Answer Key LO 2.29
Multiple choice question: Which of the following shows the correct humoral immune response after the body is exposed to antigen?
I. Plasma and memory B cells are cloned
II. The helper T cells are activated by the presence of a macrophage
III. A macrophage deteriorates the specific antigen by engulfing it
IV. Antibodies are secreted
V. A production of cytokines
A.) I, II, III, IV, V
B.) III, II, V, I, IV
C.) IV, V, I, III, II
D.) V, II, III, I, IV
The answer is B because when an antigen such as a bacterium is detected by the immune system, a macrophage will engulf the bacteria to
prevent it from attacking the body. Since the macrophage is present and it is trying to destroy the bacterium, the helper T cells are
activated. Activation of the helper T cells results in a production of cytokines that help the clonal of memory B cells and plasma cells. These
two cells secrete antibodies to help fight against bacterium.
Bacterium

Learning Log/FRQ: A macrophage is a type of phagocyte and it plays a
role in both non-specific and specific defense mechanisms.
Phagocytosis is a mechanism that occurs to remove pathogens. Draw
and label a macrophage using the following terms: bacterium,
lysosome, vacuole, pseudopodia, debris, exocytosis, and receptors.

receptors
lysosom
e

Debris

 exocytosis
 vacuole

pseudopodia
AP BIOLOGY EXAM REVIEW
Learning Objective:
(LO 3.39) The student is able to construct an explanation of how certain drugs affect signal
reception and consequently signal transduction pathways.
(SP 6.2) The student is able to build upon their understanding how certain drugs affect signal
reception and signal transduction pathways by measuring a response of the drug caffeine on
heart rate.
Explanation: By measuring a physiologic response to the drug caffeine ; the student will observe
the response of neurons to signal and transduction path ways of a drug. The drug caffeine in
coffee interacts with neuronal cell membranes in the brain. The adenosine 2A receptor on the
cell membrane prevents arousal when coupled with adenosine. Caffeine has a structure similar to
adenosine and binds to the receptor site and acts as an antagonist that binds with the receptor
and prevents normal functioning. The result is increased heart rate and alertness. Eventually,
after caffeine levels decrease, adenosine again binds with the receptors and the neurons return
to a more rested state.
Questions
What are the three steps in signaling
transduction?
A. Reception, Transduction, Electrophoresis
B. Transduction, Phosphorylation, Response
C. Reception, Transduction, Response
D. Synthesis, Transcription, Response
Briefly describe the cellular response to the
drug, caffeine’s, effect on cells
Answers
•
•
C. Reception, Transduction, Response
Free response: The caffeine molecule attaches to adenosine receptors on neurons.
Its molecular structure is similar to adenosine. Adenosine has the effect of causing
drowsiness. Caffeine’s molecular structure is similar to adenosine and attaches to
the adenosine receptor causing an antagonistic response. The response causes a
heightened state of alertness and will cause the heart rate to increase. This can be
measured by monitoring pulse rate. As a cup of coffee is consumed, adenosine
receptors receive the caffeine molecule and neurons transduce the signals to to
heart muscle cells and the circulatory system to increase heart rate and blood flow.
The levels of caffeine rise as coffee is ingested. Eventually, after all the coffee is
consumed, cellular response will peak and gradually return to normal levels as
caffeine levels fall and adenosine again attaches to receptors creating a state of
drowsiness. A plot of heart rate (pulse rate) should show an increasing heart rate
that reaches a plateau and then falls to a normal baseline rate.
LO 1.23: The student is able to justify the selection of data that address questions
related to reproductive isolation and speciation. [See SP 4.1]
SP 4.1: The student can justify the selection of the kind of data needed to answer a particular scientific question.
Explanation: Speciation may occur when two populations become reproductively isolated from each other. Reproductive isolation can
occur when species become physically separated by a geographic barrier such as an ocean or a mountain range. When species are
geographically isolated the species evolve in their own individual environments and genetic drift, or changes in the frequency of genes
present in a species population, will occur. Various pre-and
post-zygotic mechanisms also contribute to speciation in that the mechanisms maintain reproductive isolation and prevent gene flow.
Pre-zygotic mechanisms that would maintain reproductive isolation include habitat isolation: where the species would not come in contact
with one another; temporal isolation: where the species mate during different times of day or season; behavioral isolation: where mating
behaviors do not correspond between species; and mechanical isolation: where the reproductive parts “don’t fit.” Post-zygotic mechanisms
that would maintain reproductive isolation include gamete isolation, reduced hybrid viability, reduced hybrid fertility and hybrid
breakdown. Speciation results in diversity of life forms; new species arise from reproductive isolation over time, which can involve scales of
hundreds of thousands or even millions of years, or speciation can occur rapidly through mechanisms such as polyploidy in plants.
M.C. Question:
For the following question refer to this hypothetical
situation:
A female bird, full of fertilized eggs, flies to a new island
uninhabited by any other birds of her species. Thousand of
years later, her numerous offspring occupy the island;
however none of them resemble her. There are, instead,
several species each of which eat a certain type of food.
Which of the following would not aid in determining what
caused the speciation among the birds?
a) Information that reveals the differing climates on the
island cause some species to mate at different times
than others
b) Information that reveals some birds eat fish from the
ocean while others eat seeds and berries
c) Information that reveals over time some bird species
have grown larger than other and the two species are
unable to reproduce due to mechanical isolation
d) Information that reveals each food source the
different species eat are located on segregated parts
of the island
Learing Log/ FRQ Question:
a) Suppose you are studying 2 species of monkeys that live in the rainforest and are
not known to interbreed. One species feeds & mates in the treetops and the
other on the ground. But in captivity, the monkeys can interbreed and produce
viable, fertile offspring. Explain what type of reproductive barrier most likely
keeps these species from interbreeding in nature?
b) Suppose the monkeys were not able to produce viable, fertile offspring in
captivity; then what other reproductive barriers could have been discouraging
the monkeys to interbreed in their natural setting?
LO 1.23: The student is able to justify the selection of data that address questions
related to reproductive isolation and speciation. [See SP 4.1]
SP 4.1: The student can justify the selection of the kind of data needed to answer a particular scientific question.
M.C. Question Answer Explanation:
For the following question refer to this hypothetical situation:
A female bird, full of fertilized eggs, flies to a new island uninhabited by any other birds of her species. Thousand of years later, her
numerous offspring occupy the island; however none of them resemble her. There are, instead, several species each of which eat a
certain type of food.
Which of the following would not aid in determining what caused the speciation among the birds?
a) Information that reveals the differing climates on the island cause some species to mate at different times than others – incorrect
because mating at different times would cause temporal isolation among the species
b) Information that reveals some birds eat fish from the ocean while others eat seeds and berries –correct because the type of food
the birds eat does not indicate any reproductive isolation
c) Information that reveals over time some bird species have grown larger than other and the two species are unable to reproduce due
to mechanical isolation – incorrect because if the “parts don’t fit” then mechanical isolation would lead to reproductive isolation
d) Information that reveals each food source the different species eat are located on segregated parts of the island – incorrect because if
the food sources are located in segregated areas then the birds habitats would be segregated, creating habitat isolation
Learning Log/ FRQ Style Question Rubric:
Part a)
-student should express that habitat isolation is the cause of the reproductive isolation
-student should explain that the monkeys in the tree tops and the monkeys on the ground floor do not interact because
their habitats do not overlap, thus they do not come into contact to mate
- when in captivity the monkeys will be in the same habitat therefore they can reproduce
Part b)
- student should express that because the monkeys were not able to produce viable, fertile offspring, there would be
reproductive barriers at play between the two monkeys.
-student should expand upon both pre and post-zygotic mechanisms that would maintain reproductive isolation besides
habitat isolation; including temporal isolation: where the species mate during different times of day or season;
behavioral isolation: where mating behaviors do not correspond between species; and mechanical isolation: where the
reproductive parts “don’t fit.” Post-zygotic mechanisms that would maintain reproductive isolation include gamete
isolation, reduced hybrid viability, reduced hybrid fertility and hybrid breakdown.
-extra point awarded if students connect the reproductive isolation to speciation between the two monkeys