2nd Period Review Projects
2015
LO 3.13: The student is able to pose questions about ethical, social, or medical issues surrounding
human genetic disorders.
SP 3.1: The student can pose scientific questions.
Explanation: A human genetic disorder is when there is a mutation occurs, normally due to either a nondisjunction or specific
chromosomal changes. Human genetic disorders can be seen as dominant or recessive. The disorders are passed on from
parent to offspring. One mode of transmission would be a sex-linked disease, like X-linked colorblindness. Due to the fact that
the disease is sex-linked, it is more common in males, since they only have one X chromosome. An example of a disease
resulting from a nondisjunction is down syndrome. It is commonly referred to as trisomy 21 because there are three number
21 chromosomes instead of two. A ethical issue associated with down syndrome is when an expectant mother finds out her
child has down syndrome and she must decide whether to have the baby or abort it. In making this decision the mother
probably considers the life her child would have and see the negative social affects it presents. Questions like “Will my child
have friends?” and “Will he or she lead a normal life?” would pop into the mothers head. Huntington’s disease is passed on
through the acquiring of a dominant allele. Huntington’s disease is a degenerative disease of the nervous system. It is lethal
dominant, which means if a person does in fact acquire one dominant allele they will die from the disease. It is hard to
diagnose because the phenotype does not show up until ages 35-45, so it is very difficult to combat. An ethical issue
associated with it is couples who have Huntington’s disease in their family must decide whether or not to have children. The
parents would be concerned that their child might end up with the disease and then the weight of that bad news would weigh
on their shoulders because they decided to have the child.
M.C. Question: Which of the following is the most relevant to a person with down syndrome when deciding if they should
have children?
Meiosis I
A. Will my disorder be passed onto my children?
B. Is it possible for me to have children?
Nondisjunction
C. Will my child resent me?
Meiosis II
D. Can I provide a good life with my child?
Nondisjunction
E. Will my child develop properly in the womb?
Gametes
Learning Log/FRQ-style Question: When a couple is preparing to
have children, they realize one of them is at risk for Huntington’s
disease, as it runs in their family. What steps should they take in
order to make sure that the disease will not be passed on?
n –1
n+1
n
n
n1
Number of chromosomes
(a) Nondisjunction of homologous
(b) Nondisjunction of sister
n+1
n+1
n–1
chromosomes in meiosis I
chromatids in meiosis II
ANSWER KEY- LO 3.13
M.C. Question: Which of the following is the most relevant to a person with down syndrome
when deciding if they should have children?
A. Will my disorder be passed onto my children?
B. Is it possible for me to have children?
C. Will my child resent me?
D. Can I provide a good life with my child?
E. Will my child develop properly in the womb?
When a couple is preparing to have children, they realize one of them is at risk for
Huntington’s disease, as it runs in their family. What steps should they take in order to
make sure that the disease will not be passed on?
The couple should begin to ask difficult questions, like the social and ethical issues
surrounding their decision. The couple should consider genetic counseling where a trained
individual can analyze the risk they posses of having a child who will acquire Huntington’s
disease. The genetic counselor will be able to advise the couple on what will be best in
regards to the future children. The genetic counselor can advise them on the issues of
whether or not having a child presents any medical, social, or ethical issues. Also, whoever
in the couple is at risk of Huntington’s disease can have genetic tests done in order to see
whether or not they indeed have the disease. Taking preventative measures will ensure
that the couple can best prepare to make the right decisions in regards to starting a family.
LO 2.2 The student is able to justify a scientific claim that free energy is required for living systems to maintain organization, to grow
or to reproduce, but that multiple strategies exist in different living systems. [See SP 6.1]
6.1 The student can justify claims with evidence
Explanation: Free energy is the byproduct of living things’ ability to extract energy produced by
exergonic reactions of other organisms and use that energy to fuel its own endergonic reactions to
maintain their own cellular organization. Amino acids, for example, are a great representation of the
usage of free energy; in each endergonic reaction amino acids are added one at a time to create a
growing chain. These amino acids, which could not be linked together without the usage of free
energy, form together to create proteins, thus helping in the organization of the organism into
different products or working cell parts; this energy similarly, can also be captured in plants through
photosynthesis. These then perform actions individually and cooperatively relating to reproduction
and growth.
Free response question:
Multiple choice question:
In plants, exergonic energy is
harvested from protons
Molecular free energy is energy
obtained through
that originates from protons
photosynthesis , the process
relayed or passed on from the
of absorbing energy by using
sun. Which of these cycles proves
certain types of chlorophyll
this by directly converting
and pigments. Animal cells
exergonic proton energy into Free
must then intake this energy
energy for living organisms?
using their own unique
systems. List two different
A. Glycolysis
B. The Krebs cycle
techniques in which energy
C. DNA replication
is harvested in animals and
D. Photosynthesis
describe the pivotal
processes of one technique.
Multiple choice question response: The correct answer to this multiple choice question is D, photosynthesis. The answer is
D due to the fact that all of the other listed options have to get their energy from other organisms which have already converted
the energy. Since the 1st law of thermodynamics states that energy can never be created or destroyed, it becomes evident that
energy can only be passed on through the food chains of living organisms, excluding of course the autotrophes who can harvest
their own energy through photosynthesis. All energy in an ecosystem can be traced back to the bottom of the pyrimid, or the
autotrophes who’s energy can be traced back to the sun, thus justifying the claim that all free energy is relayed by the sun.
Free response question response: Free energy in animal cells are acquired by utilizing cellular respriation which harvests
energy by breaking down carbohydrates. Two cycles that utilize this system would be glycolosis and the Krebs cycle in living
animals. The Krebs Cycle also known as the Citric Acid Cycle, generates energy through the oxidation of acetate which is produced
from the broken down carbohydrates. The consumption of the acetate and water by the cycle reduces NAD+ to NADH and
produces carbon dioxide as a byproduct. The NADH produced is then eventually fed into the electron transport chain finally leading
to the development of usable chemical energy, also known as ATP. In simpler terms, both the Krebs Cycle and glycolosis produce
ATP through the conversion of sugar molecules.
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: Any change in the environment can have effects on the genotypic expression of the phenotype. These environmental factors
have the ability to influence many traits both directly and indirectly. Examples of environmental factors are heat, cold, sun, pollution,
global warming, location of land, natural disasters and many others. Ultimately, when an environmental factor strikes, those who have the
genotypes that best fit with the environmental change are the ones who survive and reproduce. This is known as natural selection, the
survival of the fittest who are able to successfully reproduce. An example of an environmental factor is sex determination in reptiles. Such
as when the temperature is very warm turtles will produce mainly females and when the temperature is cooler they will produce primarily
males. This is demonstrated in the figure at the bottom of the page between different populations and there proportion of males during
different temperatures. Graph A represents a species when more males are born in higher temperatures. Graph B represents a species
where more males are born in lower temperatures and graph C when more males are born in very low or very high.
M.C. Questions: Suppose you have a population of black and white butterflies on a tropical island. Right now there are many more white
butterflies than there are black butterflies. A major business decides to build a factory right by the coast of this Island and near the major
population of butterflies. What would suppose would happen in the future?
A) The population of butterflies will stay the same
B) The population of butterflies will have the same amount of black as white
C) The population of black butterflies will increase and white will decrease
D) The butterflies will become extinct
Learning Log/FRQ-style Question: The artic fox thrives in its artic environment. Right now it is the month of the January and the fox is a
light white color.
A)What are some possible adaptations and characteristics of the fox that help it thrive?
B) What is the main factor that explains the phenomena illustrated in part A?
C) What factors would natural selection favor about the summer?
Suppose you have a population of black and white butterflies on a tropical island. Right now there are many more white butterflies
than there are black butterflies. A major business decides to build a factory right by the coast of this Island and near the major
population of butterflies. What would suppose would happen in the future?
A) The population of butterflies will stay the same
B) The population of butterflies will have the same amount of black as white
C) The population of black butterflies will increase and white will decrease
D) The butterflies will become extinct
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The artic fox thrives in its artic environment. Right now it is the month of the January and the fox is a light white color.
A)What are some possible adaptations and characteristics of the fox that help it thrive?
B) What is the main factor that explains the phenomena illustrated in part A?
C) What factors would natural selection favor about the summer?
A) Characteristics of the fox that allow it to thrive are its ability to change colors according to the current season. In the
summer this fox will turn a light brown color. This light brow fur color allows the fox to stay camouflaged in the summer
and hide from predators. The white fur color in the winter allows the fox to stay camouflaged in the winter and also hide
from potential predators. These adaptations allow this certain population of fox’s to thrive in their community. Natural
selection has allowed to fox’s that are best able to adapt to their surroundings thrive and therefore reproduce creating a
large population of this certain fox.
B) The main factor that explains this phenomena is the environment. The environment impacts the genotypic expression of
the phenotype by having those best suited to the environment thrive and then reproduce.
C) Natural selection would favor a light brown hair color to camouflage along with a lighter amount of fur to keep cool on hot
summer days. Being able to blend in and keeping a favorable body temperature are key to survival for this fox.
LO 4.2: The student is able to refine representations and models to explain how the subcomponents of a
biological polymer and their sequence determine the properties of that polymer.
SP 1.3: The student can refine representations and models of natural or man-made phenomena and
systems in the domain.
Explanation: Proteins, for example, are a chain of amino acids. They have primary, secondary, tertiary,
and sometimes quaternary structure. Starting with the secondary structure, the R groups of the amino
acids interact with one another, which gives the protein its tertiary structure. The properties of the R
groups drive the folding of the protein. Because proteins are found in an aqueous environment, the
amino acids with hydrophobic R regions will get folded in the interior of the protein and those with
hydrophilic R regions will be found on the exterior of the protein, where they can come into direct
contact with the aqueous environment. This folding determines the protein’s shape and therefore its
function as well. The active sites of proteins contain certain amino acids, and the R groups of these
amino acids determine which substrates are able to bind. The subcomponents of lipids, carbohydrates,
and DNA similarly affect the properties of these polymers.
MC Question: A protein has primary, secondary, and tertiary.
Suppose the hydrogen bonds within the protein are disrupted.
Using the figure to the right and your knowledge of proteins,
which level of structure will remain unchanged?
A) Primary
B) Secondary
C) Tertiary
D) All levels will be disrupted
FRQ Question: Suppose there is a point genetic mutation (no frameshift) in the gene coding for a
particular protein. How will this affect the function of the protein? Will the function always be
compromised? In your response, demonstrate the properties of each level of protein structure.
Answer Key- LO 4.2
A protein has primary, secondary, and tertiary. Suppose the hydrogen bonds within the protein are
disrupted. Which level of structure will remain unchanged?
A) Primary
B) Secondary
C) Tertiary
D) All levels will be disrupted
Suppose there is a genetic mutation that results in one amino acid being different from normal. How will
this affect the function of the protein? In your response, explain the properties of each level of protein
structure.
Primary structure is the sequence of amino acids. If one amino acid is
different, the primary structure of the protein changes. Secondary structure
involves hydrogen bonds between the amino acids, but with the primary
structure being different, the hydrogen bonds will form differently as well.
Lastly, the globular structure is formed by interaction between the beta and
alpha pleated sheets (secondary structure.) With the differences in the
secondary structure, the tertiary level of protein structure will also be
impacted. Protein function depends on structure, so because the protein
has a completely different globular shape due to the genetic mutation, it
will be unable to perform its function.
However, it is plausible that there is no change in protein function. This can
occur if there is a silent mutation, when the change in the nucleotide
sequence does not result in a different amino acid. Therefore, the primary,
secondary, and tertiary levels of structure will remain the same, and the
protein will not change.
LO 4.4: student is able to make a prediction about interaction of subceleular organelles.
SP 6.4: student can make claims and predictions about natural phenomena based on scientific
theories and models.
Connection: the endomembrane system is what regulates protein production in the cell, as well
as keeping what goes in and out of the cell in check. The endomembrane system includes the
nuclear envelope, the endoplasmic reticulum, lysosmes, golgi aparatus, and vacule which is only
found in plant cells. The main function of the endomembrane is protein synthesis, and well as
cell digestion. It is also responsible for moving proteins to other parts of the cell, or even outside
the cell.
MC: this organelle is a part of the endomembrane that is responsible for intracellular digestion
using hydrolytic enzymes?
A- endoplasmic reticulum
B- ribosome
C- lysosomes
D- mitochondria
E- C and D are both correct
FRQ: in detail describe the distinct function of
the following: nuclear envelope, endoplasmic
reticulum,Golgi aparatus,and lysosomes.
Answer key
MC: this organelle is a part of the endomembrane that is responsible for intracellular
digestion using hydrolytic enzymes?
• A- endoplasmic reticulum
• B- ribosome
• C- lysosomes
• D- mitochondria
• E- C and D are both correct
• FRQ: in detail describe the distinct function of
the following: nuclear envelope, endoplasmic reticulum,Golgi aparatus, and lysosomes.
The nuclear envelope which surrounds the cells nucleus is made to be selectively
permeable which means it only allows certain things in, and for others that are too
large the nuclear envelope contains pores that allows RNA in because it’s simply too
big to diffuse through the envelope. The endoplasmic reticulum, best known as ER
exist in two different forms, rough and smooth. The rough ER contains ribosomes in
order to produce proteins, while the smooth ER synthesizes different hormones such
as steroids and stores ca+. The golgi aparatus acts as a factory receiving substances
from the rough ER and sends them out to different parts of the cell. Lysosomes
contain enzymes that help break down old cell parts and digest it using a process
called autophagy. The destruction of the cell by its own is known as apoptosis.
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LO 1.29 The student is able to describe the reasons for revisions of scientific
hypotheses of the origin of life on Earth.
SP 6.3 The student can articulate the reasons that scientific explanations and theories
are refined or replaced.
Theories on the origin of life on Earth have been rewritten and revised numerous times
since scientists began speculating and researching. Experiments and technological
advancements have proven, disproven or modified theories on how life began on Earth
multiple times over the years. For example, scientists Miller and Urey conducted
controlled experiments using technologically advanced materials in order to prove the
Oparin-Haldane hypothesis on the synthesis of organic compounds. Innovative
techniques have been used to prove hypotheses on the exact time period when life on
Earth originated. An example of this is radiometric dating, where the half-life of
radioactive isotopes is measured in order to determine age. Fossil records of
prokaryotes determine age of earliest life and can change theories on the origin of life
on Earth. The oldest known fossils are stromatolites (rocklike structures composed of
bacteria and sediment) that can help scientists estimate the time period for the origin
of life on earth, thus proving and possibly revising various scientific hypotheses.
Multiple Choice Question- Anna claims that life on Earth originated in conditions very
similar to the conditions of the atmosphere of Earth today. She uses the Miller-Urey
experiment to support her theory because of the use of methane, ammonia and water
vapor, which are all gases found in the atmosphere today. Is her hypothesis correct?
A) Yes because the Miller Urey experiment was successful in determining that
organic compounds were formed from simple molecules.
B) No because conditions on Earth were different since the atmosphere was a
reducing environment in order to create organic compounds from simple
molecules.
C) Yes because in order for life on Earth to still exist, conditions have to be the same.
D) No because conditions on Earth were different due to the warming of the Earth,
causing water vapor to condense into oceans.
FRQ- Maria believes origin of life on Earth occurred approximately 3.8 billion years ago
and her colleague Andrew believes life on Earth began 2 billion years ago. Briefly
explain three ways the scientists could prove their theory and cause their colleague to
revise.
Answer Key- L.O. 1.29
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Anna claims that life on Earth originated in conditions very similar to the conditions of the atmosphere of
Earth today. She uses the Miller-Urey experiment to support her theory because of the use of methane,
ammonia and water vapor, which are all gases found in the atmosphere today. Is her hypothesis correct?
– A) Yes because the Miller Urey experiment was successful in determining that organic compounds
were formed from simple molecules.
– B) No because conditions on Earth were different since the atmosphere was a reducing
environment in order to create organic compounds from simple molecules.
– C) Yes because in order for life on Earth to still exist, conditions have to be the same.
– D) No because conditions on Earth were different due to the warming of the Earth, causing water
vapor to condense into oceans.
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Maria believes origin of life on Earth occurred approximately 3.8 billion years ago and her colleague
Andrew believes life on Earth began 2 billion years ago. Briefly explain three ways the scientists could
prove their theory and cause their colleague to revise.
– The scientists could use radiometric dating with fossils to prove their theories. Radiometric dating
utilizes the half-life of radioactive isotopes, which is the number of years it takes for half of the
isotope to decay in the fossil. Calculating the approximate age of the origin of life through
radiometric dating is a valid method because half-life is unaffected by pressure, temperature, etc.
Scientists could also utilize the geologic record, which divides the earth into eons, eras, periods and
epochs in order to classify the time periods in which certain forms of life emerged. This could be
used to prove or disprove a theory on the date of origin of life on Earth. A third way to support
their individual theories is through the study of stromatolites to approximate the date of the
emergence of the first prokaryotes. Stromatolites are rocklike structures composed of layers of
bacteria and sediment that can be found in bays. They can be used to determine time periods of
the first bacterial communities, where it can be concluded that the origin of life on Earth occurred
previous to those dates.
LO 2.40: The student is able to connect concepts in and across domain(s) to predict how environmental factors
affect responses to information and change behavior.
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: In photoperiodism in plants, for example, a critical
dark period controls whether or not the plant flowers. The
environment ultimately determines whether a plant will flower. If
the plant receives enough of its critical dark period and is
uninterrupted by red light (not followed by far red light), then the
plant will flower. This later affects whether or not the plant will be
pollinated and what hormones are present in the plant. Many
animals and plants are greatly affected by environmental changes
such as this.
M.C. Question: Which of the following is not true about
hibernation?
A) It is specific to endotherms
B) The animal’s metabolic rate is decreased
C) Less energy is used in order to maintain homeostasis
D) It is a learned behavior
Learning Log/FRQ-style Question: The peppered moth, found in
Great Britain, used to be white, however due to an increase in
pollution, the peppered moth is now brown and black. There has
recently been an increase in the number of white peppered
moths. What caused the physical changes within the peppered
moth population? What does the number of increased white
peppered moth suggest?
ANSWER KEY-LO 2.40
M.C. Question: Which of the following is not true
about hibernation?
A) It is specific to endotherms
B) The animal’s metabolic rate is decreased
C) Less energy is used in order to maintain
homeostasis
D) It is a learned behavior
The peppered moth, found in Great Britain, used to be
white, however due to an increase in pollution, the
peppered moth is now brown and black. There has
recently been an increase in the number of white
peppered moths. What caused the physical changes
within the peppered moth population? What does the
number of increased white peppered moth suggest?
In a heavily polluted area, a white moth would be obvious whereas a dark moth could rely
on camouflage. A genetic mutation occurred which caused a peppered moth to be darker
in color. Natural selection favored this and so that moth had a higher chance of passing
the dark coloration on to his/her offspring. As the dark colored moths continued to
reproduce and increased in number, the white moths began to decrease in number. The
increasing numbers of white moths suggests that the pollution in Britain is decreasing.
LO 3.4 The student is able to describe representations and models illustrating how genetic information is translated into
polypeptides.
SP 1.2 The student can describe representations and models of natural man-made phenomena and systems in the
domain.
Explanation: Genetic information is translated into polypeptides through the process of DNA translation. During said
process, messenger RNA (mRNA) yielded through transcription, is read by a ribosome complex to produce specific
polypeptide chains made of amino acids. One biological model demonstrating this process is the formation of the insulin
protein. In this naturally occurring phenomena, following the activation of the INS gene and production of mRNA, the
messenger RNA is transported to the ribosome and translated into Insulin polypeptides.
M.C. Question: Which type of RNA is responsible for
attaching amino acids to a polypeptide chain during
translation?
A) mRNA
B) snRNA
C) t RNA
D) aRNA
Learning Log/ FRQ Question: A designated protein is
artificially synthesized under the same conditions in
both a eukaryotic and a prokaryotic cell. If no genetic
differences affect production of the protein, explain
why protein synthesis might occur at an accelerated
rate in the prokaryotic cell.
ANSWER KEY- LO 3.4
Which type of RNA is responsible for attaching amino acids to a polypeptide chain during translation?
A)
B)
C)
D)
mRNA
snRNA
tRNA*
aRNA
A designated protein is artificially synthesized under the same conditions in both a eukaryotic and a prokaryotic cell. If no
genetic differences affect production of the protein, explain why protein synthesis might occur at an accelerated rate in the
prokaryotic cell.
Unlike the highly compartmentalized eukaryotic cell, the prokaryotic cell is mainly made up of a cytoplasm containing
free ribosomes and genetic material, surrounded by a plasma membrane. The absence of a nucleus allows the
prokaryotic cell to simultaneously transcribe and translate the same gene, while transcription and translation are
segregated by the nuclear envelope in the eukaryotic cell. Therefore, the protein is synthesized quicker in the prokaryote,
because it can undergo both transcription and translation at the same time, accelerating the process.
LO 3.28 The student is able to construct an explanation of the multiple processes that increase variation
within a population.
SP 6.2 The student can construct explanations of phenomena based on evidence produced through
scientific practices.
Explanation- Genetic Variation within a eukaryotic population is achieved through sexual interaction with other members of the
same species. The ways in which eukaryotes are able to retain variation in the population are through: Crossing over, which is
when 2 homologous chromosomes line up at specific genes and exchange genetic material, Independent assortment, when
chromosomes are randomly distributed among the 4 gametes, and also through random fertilization, where any one of the male
gametes fertilizes any one of the female gametes.
Genetic Variation within a prokaryotic populations is achieved through environmental and some “sexual”
interaction. Variation can take place through: transformation, which is the uptake of environmental DNA, transduction, which is
the process by which viruses implant DNA into a prokaryote, also through conjugation, which is bacteria “sex” where plasmids are
carried to other bacteria over the
, and lastly transposition where DNA sequences are transferred to other strands of DNA.
Also mutation is present in both Eukaryotes and Prokaryotes which is also provides variation within populations
Multiple choice question- which of the following is NOT an
example of increasing variation within a population:
A). Independent Assortment
B). Transposition
C). Translation
D). Conjugation
Free Response QuestionDescribe the process of Meiosis and how it relates to key processes
that increase genetic variation in the offspring.
Answer key LO 3.28
which of the following is NOT an example of increasing variation within a population:
A). Independent Assortment
B). Transposition
C). Translation
D). Conjugation
Translation is the process by which RNA is translated in amino
acid chains that make up proteins. It is not a process by which
variation is increased in a population.
Meiosis is the process of production of gametes in a eukaryote. Meiosis unlike mitosis divides into 4 separate cells, and each of
these cells contains different combinations of chromosomes due to independent assortment , the process by which chromosomes
are divided into separate cells randomly. But before the chromosomes separate, the homologous chromosomes are lined up with
one another in the middle of the cell. While they are lined up crossing over takes place which randomly swaps genetic material
with its homologous chromosome which increases variation even more after independent assortment .
The last major process that increases genetic variation is random fertilization where any of the many
combinations of a male gamete fertilizes any of the combinations of a female gamete. And also when
you’re dealing with genetic variation you have to account for mutations, which increase variation and
sometimes add variation into a population that wasn’t already present.
LO 3.8: The student can describe the events that occur in the cell cycle.
SP 1.2: The student can describe representations and models of natural or man-made phenomena and systems in the domain.
Explanation:
The cell cycle is broken up into two phases: Interphase,
which takes up 90% of the cycle time, and the mitotic
phase, which takes up 10%. The cell grows by producing
proteins and cytoplasmic organelles during the G1, S, and
G2 phases of Interphase, but only duplicates
chromosomes during the S phase. The S phase is the
most time-consuming phase, occupying roughly half of
the time spent in the cell cycle. There are checkpoints at
each of these stages to stop a cell to make sure the
necessary criteria are met before it can continue through
the cell cycle. (Figure 1.1) If it does not pass the
checkpoint, it will exit the cycle and switch to a nondividing state, G0. (Figure 1.2) The majority of the cells in
the body are in the G0 phase. The first step of mitosis is
prophase, where the mitotic spindle begins to form,
nucleoli disappear, and chromatin fibers become more
tightly coiled. During metaphase, which is the longest
stage of mitosis, centrosomes are at opposite ends of the
cell and align at the metaphase plate in the middle of the
cell. For each chromosome, the kinetochores of the sister
chromatids are attached to kinetochore microtubules
coming from opposite poles. The next stage in anaphase,
which is the shortest stage of mitosis. During this stage
the two sister chromatids of each pair are separated, and
each chromatid becomes its own chromosome. The two
chromosomes move toward opposite ends of the cell as
their kinetochore microtubules shorten. The cell
elongates as the nonkinetochore microtubules lengthen.
Two daughter nuclei begin to form in the cell during the
next stage, Telophase. Nuclear envelopes arise from the
fragments of the parent cell’s nuclear envelope and the
chromosome becomes less condensed. (Figure 1.3)
Instead of dividing mitotically, a cell, most notably sex
cells, divides by meiosis. Unlike mitosis, meiosis creates
genetic variability through crossing over. It also differs
from mitosis because there are two stages of prophase,
metaphase, anaphase, and Telophase, which results in
four genetically distinct daughter cells.
Figure 1.1
Figure 1.2
FRQ Question:
A. Explain what happens during
each phase of the cell cycle.
Include in your answer the
stages of Interphase, Prophase,
Metaphase, Anaphase,
Telophase, and Cytokinesis in
mitosis, or those plus Prophase
II, Metaphase II, Anaphase II,
and Telophase II in meiosis.
B. Explain the differences
between Mitosis and Meiosis,
and how those differences lead
to genetic variation in the
daughter cells in meiosis.
Figure 1.3
M. C. Question:
What stage of the cell cycle is occurring in
the image provided?
A.
B.
C.
D.
E.
Prophase
Anaphase
Metaphase
Interphase
Telophase
Answer Key for LO 3.8
M. C. Question:
What stage of the cell cycle is occurring in the image provided?
A. Prophase
B. Anaphase
C. Metaphase
D. Interphase
E. Telophase
A. Explain what happens during each phase of the cell cycle. Include in your answer the stages of Interphase, Prophase, Metaphase,
Anaphase, Telophase, and Cytokinesis in mitosis, or those steps plus the additional ones in meiosis. B. Then explain the differences between
Mitosis and Meiosis, and how those differences lead to genetic variation in the daughter cells during meiosis.
A. Interphase: G1, S, G2, cell grows during G1, chromosomes are duplicated in S, cell continues to grow as it prepares for division in G2.
Mitosis: Prophase: chromatin fibers become more condensed, nucleoli disappear, each chromosome appears as sister chromatids, mitotic
spindles begin to form
Metaphase: centromeres at opposite sides of cell, chromosomes convene on metaphase plate, kinetochores of sister chromatids attached to
kinetochore microtubules
Anaphase: sister chromatids separate forming new chromosomes, liberated chromosomes move toward opposite ends of cell, cell elongates
Telophase: daughter nuclei begin to form, nuclear envelopes arise from fragments of parent cell nuclear envelope, chromosomes become less
dense, mitosis over
Cytokinesis: division of cytoplasm, results in two daughter cells
Meiosis: Prophase I: chromosomes begin to condense, crossing over occurs, homologous chromosome pair, nuclear envelope broken down
Metaphase I: homologous chromosomes (tetrads) align on metaphase plate, both chromatids are attached to kinetochore microtubules from
one pole
Anaphase I: chromosomes move toward poles, sister chromatids remain attached, homologous chromosomes move toward opposite poles
Telophase I & Cytokinesis: each half of cell has complete haploid set of chromosomes, each chromosome still composed of sister chromatids,
cytoplasm splits
Prophase II: spindle apparatus forms
Metaphase II: chromosomes positioned on metaphase plate, chromatids not genetically identical because of crossing over in meiosis I
Anaphase II: centromeres of each chromosome separate, sister chromatids come apart
Telophase II & Cytokinesis: nuclei form, chromosomes become decondensing, cytokinesis occurs, meiotic division of one parent cell produces
four genetically distinct daughter cells
B. Meiosis is a reduction division while cells that go through mitosis have the same number of chromosomes.
Meiosis creates genetic variation while mitosis produces a clone.
Meiosis is two consecutive nuclear divisions while mitosis is just one.
Crossing over in prophase I creates genetic variation in meiosis
LO 3.44: The student is able to describe how nervous systems detect external and internal signals.
SP 1.2: The student can describe representations and models of natural or man-made phenomena
and systems in the domain.
Explanation: For a stimulus to be detected, its energy level must exceed the absolute threshold. If the
stimulus does surpass the absolute threshold, then the stimulus information will be transmitted to
the central nervous system (CNS), where a decision on how to respond to the stimulus is made. An
external stimulus is any signal that originates from an outside organism, while an internal stimulus
is any signal that comes from the need to maintain the body’s homeostatic system.
MC Question: Which of the following is a response to an external stimulus?
A. An animal panting/sweating
B. A fight or flight response
C. A plant transpiring
D. Shivering
Learning Log/FRQ-style Question: Compare and contrast how the nervous system detects internal and
external signals.
ANSWER KEY- LO 3.44 (answer is bolded)
Which of the following is a response to an external stimulus?
A. An animal panting/sweating
B. A fight or flight response
C. A plant transpiring
D. Shivering
Compare and contrast how the nervous system detects internal and external signals.
Sensory receptors are where stimuli go to influence a reflex by using stimulus transduction.
Just like touch receptors found in the skin or light receptors in the eye these sensory receptors
can receive information from outside the body as well as from inside the body by using
chemoreceptors and mechanoreceptors. All stimuli that is received by the body is used help us
react and adapt to the environment around us. An internal stimulus is used to maintain our
homeostatic levels within the body, such as hunger, thirst and fatigue. External stimuli are used
to produce systematic responses ,to our environment, throughout the body. This includes the
body’s natural fight or flight response.
LO 3.46: The student is able to describe how the vertebrate brain integrates information to produce a response.
SP 1.2: The student can describe representations and models of natural or man-made phenomena and systems in the domain.
Explanation: There are three stages in the integration of information by the brain to produce a response. The first stage is sensory
input, which involves sensors detecting a stimulus in the environment(sight, smell, touch, taste, hearing) or internally and sensory
neurons transmit the information gathered from the Peripheral Nervous System to the Central Nervous System (Brain and Spinal
Cord). This information is sent through sensory neurons through a series of action potentials caused by thresholds being met with
each neuron receiving the signal through its dendrites by traveling across a synapse passing the signal through neurotransmitters and
then sending another action potential starting at the axon hillock and going down the axon to the next neuron. The action potential
is initiated when the neuron depolarizes to -55mV. The resting membrane potential is reestablished through sodium/potassium
pumps using active transport and ATP to polarize the neuron again so that it may have another action potential. The second stage is
integration, which involves the sensory input being received and interneurons integrating and making sense of the input received.
This is done by the interneurons obtaining signals from the brain to take into account immediate context of the signal as well as
understanding of past experiences. After the sensory input is integrated, there is a third stage which is the motor output. The motor
output leaves the CNS where integration occurs via motor neurons which pass on the signal to effector cells, which can be muscular
or endocrine cells, and results in muscle contractions or any output that produces motion as a response. This can be represented by
information being taken in, made sense of, and then responding.
M.C. Question: Which of the following statements concerning information
processing for the knee-jerk reflex is true?(Refer to Figure 1:reflex reaction)
A)No signals are passed to the Central Nervous System
B)Reflexes integrate sensory input in the spinal cord
C)Interneurons are not used in reflexive responses
D)Reflexes integrate sensory input in the brain
E)Both B and C
Learning Log/FRQ-style Question: Suppose that there is a loud sound that you
hear which sounds like broken glass. You have been conditioned to react to the
sound of broken glass by kicking your leg. Explain in detail how the sound of glass
breaking is integrated in your brain and the motor response that will result.(Refer to Figure 2: overview)
Figure1=left
Figure2=down
Answer Key- LO 3.46
Which of the following statements concerning information processing for the knew-jerk reflex is true?
A)No signals are passed to the Central Nervous System
B)Reflexes integrate sensory input in the spinal cord
C)Interneurons are not used in reflexive responses
D)Reflexes integrate sensory input in the brain
E)Both B and C
More familiar
figure that
conveys same
message as
Figure 1 on
previous slide
Looking at the diagram interneurons are used in the response
eliminating A, C and E since interneurons are part of the
CNS. Since in the image these interneurons are in the spinal cord which is labeled and not the brain that
would make B the correct answer.
Learning Log/FRQ-style Question: Suppose that there is a loud sound that you
hear which sounds like broken glass. You have been conditioned to react to the
sound of broken glass by kicking your leg. Explain in detail how the sound of glass
breaking is integrated in your brain and the motor response that will result.
The sound waves from the sound are detected by sensors in the ear which use sensory neurons to
transmit the detection of the external stimuli to the brain. This sound is the sensory input. Interneurons
in the brain then process this information allowing you to recognize that it is the sound of broken glass.
Once the sound has been identified after integration in the CNS, signals are sent to motor neurons to
effector cells where some leg muscles contract in order to create a kicking motion as the motor output.
All of these signals are sent through a series of action potentials down axons to dendrites of the next
neuron using neurotransmitters to cross the synapse between each axon and dendrite.
Learning Objective 3.30
•
•
•
Learning Objective 3.30 -The student is able to use representation and appropriate models to
describe how viral replication introduces genetic variation in the viral population.
Science Practice 1.4 -The student can use representations and models to analyze situations or
solve problems qualitatively and quantitatively.
Explanation -Viral replication is not like normal replication. It results in genetic variation much faster than
normal replication, and can introduce genetic variation into the host as well. Viruses transmit DNA or RNA
when they infect a host, and they are able to integrate the host DNA into their own. This DNA results in
genetic variation due to recombination of the chromosomes from the bacterial DNA and host DNA. They
replicate via the lytic cycle or lysogenic cycle, and using the host in these cycles, they are able to form
mutations through the host pathways. Some viruses’ genetic material is made up from RNA only. These
viruses are called retroviruses, and they lack error checking mechanisms. The reason for the lack of
mechanism is due to the enzyme reverse transcriptase, which don’t allow for error checking. This allows for
higher rates of genetic variation, as they cant go back and correct the mistakes made during replication.
These all will introduce variation into to the viral population.
MC Question: Using the model to the right, which part of the
lytic cycle produces genetic variation in the viral population?
A) Step 1
B) Step 6
C) Step 3
D) Step 5
FRQ Question:
A) Using the model to the right, explain how the
transcription of phage DNA results in genetic
variation.
B) Retroviruses genetic material is made up of RNA
instead of DNA. They lack the error checking
mechanism due to the enzyme reverse
transcriptase. Explain how the lack of this
mechanism creates more genetic variation at a more
rapid pace than viruses with DNA.
Answer Key
MC Question: Using the model to the right, which part of the lytic cycle produces genetic variation in the viral
population?
A) Step 1
B) Step 6
C) Step 3
D) Step 5
Explanation: Genetic material is being transcribed along with the host bacteria, leading genetic variation in the
phage population.
FRQ Question:
Explanation:
A)Using the model to the right, explain how the transcription of phage DNA results in genetic variation.
A) When phage DNA is transcribed, it is being done so in place of the normal DNA from the host cell. When it
becomes mRNA, it will be translated and will eventually be made into phage proteins. These phage proteins
will eventually create the parts of the new phages. Both of these steps will lead to a genetic variance in the
phage’s DNA because of the genetic errors created by the host cell. The host cell is doing the transcribing and
translating, so whatever mistake it makes will eventually lead to a variation in the viral population.
B)Retroviruses genetic material is made up of RNA instead of DNA. They lack the error checking mechanism due to
the enzyme reverse transcriptase. Explain how the lack of this mechanism creates more genetic variation at a more
rapid pace than viruses with DNA.
B) Since retroviruses cannot go back and check the mistakes that it has made, any type of change will result in a
variation in the genetic material. Viruses that contain DNA as their genetic material have this error checking
mechanism, so they are able to keep genetic variation at a minimum. In retroviruses, every error in the coding will
result in a change, and this causes the rate of variation to go up compared to viruses with DNA.
l.O. 1.9: the student is able to evaluate evidence provided by data from many scientific disciplines that support biological evolution
S.P. 5.3: The student can evaluate the evidence provided by data sets in relation to a particular scientific question
•
•
•
•
•
•
Explanation: Evolution is the process by which different
organisms are thought to have developed and diversified from
earlier forms. A component of evolution is common ancestry,
the idea that organisms originate from a parent species.
Similarities in morphologies, genetic information, and
molecular information allow us to make educated deductions
about the common ancestor of different organisms. Evidence
of evolution can be found by way of analyzing data from
various disciplines. For example, mathematical models are
commonly used to demonstrate common ancestry. In regards
to evolution, the interpretation of scientific data provides
sound evidence on the relationship between organisms.
M.C. Question: Based on the figure to the right, what can best
be concluded about the relationship between the organisms?
A) All of the organisms come from a common ancestor except
for the Shark.
B) The Chicken and Iguana are more closely related than the
Chicken and Gorilla.
C) The Chicken, Iguana, Bullfrog, and Shark all may be
descendants of the Gorilla.
D) There is not enough information to determine a
relationship.
:
•
FRQ Question
•
Based on the cladogram to the right, discuss
what evidence is supported. Identify what
organism(s) is most closely related to the
human? Explain your conclusion.
•
•
•
•
•
•
M.C. Question: Based on the figure to the right, what can best be concluded about the relationship between
the organisms?
A) All of the organisms come from a common ancestor except for the Shark.
B) The Chicken and Iguana are more closely related than the Chicken and Gorilla.
C) The Chicken, Iguana, Bullfrog, and Shark all may be descendants of the Gorilla.
D) There is not enough information to determine a relationship.
Answer Choice B is correct because after analyzing the graph, one could see that
the Chicken and Iguana only differ in one amino acid, whereas the Chicken and
Gorilla differ in three amino acids. Answer A isn’t correct because all of the
organisms have enough of the same amino acids to depict common ancestry.
Choice C is incorrect because common ancestry does not mean that one species
originated directly from another, but rather descent with modification. Choice D is
wrong because there is a tremendous amount of information present about the
amino acid composition to make a sound deduction.
FRQ Question: Based on the cladogram to the right, discuss what evidence is supported. Identify what
organism(s) is most closely related to the human? Explain your conclusion.
The cladogram suggests that all of the organisms originate from a common ancestor.
This means there may be a lot of similarities in regards to their genetic makeup. The
organism most closely related to the human would be both the gorilla and chimpanzee
since the cladogram shows only a small amount of space is in between the organisms.
This small space represents closer biological relationships.
LO 3.48: The students is able to create a visual representation to describe how nervous systems detect external and internal signals.
SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain.
Explanation: The neuron is the basic structure of the nervous system that reflects function. A typical neuron has a cell body, axon, and dendrites that allow
for the detection, generation, transmission, and integration of signal information. Schwann cells (from the myelin sheath that acts as an electrical insulator
for many axons) are separated by gaps of unsheathed axon over which the impulse travels as the signal propagates along the neuron. Action potentials
propagate impulses along neurons. Membranes of neurons are polarized by the establishment of electrical potentials across the membranes. In response,
Na+ and K+ gated channels sequentially open and cause the membrane to become locally depolarized. Powered by ATP, Na+ and K+ pumps work to
maintain membrane potential. Students can use this information to create representations and models using verbal or written explanations as well as
illustrations to describe the biological processes and concepts of the detection of internal and external signals. An example of this would be the figure shown
to the right. This shows the process from stimulation, to reception, to transduction, and finally the response.
M.C. Question: The diagram below depicts the sensory transduction pathway that
occurs when olfactory receptors detect an external stimulus. Which of the following is
not true about the pathway shown?
A.) Odorants bind to odorant receptors on the plasma membrane of chemoreceptors.
B.) An influx of ions polarize the membrane, resulting in action potentials.
C.)
The second messenger opens channels in the plasma membrane that are permeable to
Na+ and Ca^2+ ions.
D.) G protein, the
enzyme adenylyl cyclase and the second messenger cyclic AMP aid in the transduction
pathway.
FRQ-style Question: The transmission of a nerve impulse between two different
neurons occurs across the synaptic cleft after being triggered by an internal
stimulus and incorporates two types of cells: presynaptic and postsynaptic.
Define the two cell types and explain the transmission process between the two
neurons, starting with the stimulation . Then, draw and label the synaptic cleft to
defend your explanation.
ANSWER KEY- LO 3.48
M.C. Question: The diagram below depicts the sensory transduction pathway that occurs when olfactory receptors detect an
external stimulus. Which of the following is not true about the pathway shown?
A.) Odorants bind to odorant receptors on the plasma membrane of chemoreceptors.
B.) An influx of ions polarize the membrane, resulting in action potentials.
C.) The second messenger opens channels in the plasma membrane that are permeable to Na+ and Ca^2+ ions.
D.) G protein, the enzyme adenylyl cyclase and the second messenger cyclic AMP aid in the transduction pathway.
The transmission of a nerve impulse between two different neurons
occurs across the synaptic cleft after being triggered by an internal
stimulus and incorporates two types of cells: presynaptic and
postsynaptic. Define the two cell types and explain the transmission
process between the two neurons, starting with the stimulation .
Then, draw and label the synaptic cleft to defend your explanation.
Once the internal stimulus has been detected, nerve impulses reaching the
presynaptic ending cause calcium to enter and pull the synaptic vesicles to
the inner surface of the presynaptic cell membrane. Synaptic vesicles merge
with the presynaptic membrane (exocytosis) and neurotransmitters are
released into the synaptic cleft. Neurotransmitters diffuse across the cleft
and fit into receptor sites on the postsynaptic cell membrane (lock&key
method). This generates an action potential in the postsynaptic membrane
and the nerve impulse continues on. After the release, neurotransmitters
quickly break down and are reabsorbed by presynaptic endings.
Sample Drawing
LO 1.16: The student is able to justify the scientific claim that organisms share many
conserved core processes and features that evolved and are widely distributed among
organisms today.
SP 6.1: The student can justify claims with evidence.
Explanation: DNA and RNA, which carry genetic information, are conserved across all
domains of life. The existence of these two biological macromolecules is proof that all
organisms share a common ancestor, as all living things contain either DNA or RNA.
Genetic information is carried in DNA and RNA through the processes of transcription,
translation, and replication. These three processes are further proof that organisms
share a common ancestor because they occur in all DNA and RNA. Another example of a
shared process in all living organisms is the electron transport chain (ETC). Located in the
mitochondrial membrane within animal eukaryotic cells, the thylakoid membrane of the
chloroplast within plant eukaryotic cells, and the cell membrane within bacterial cells,
the ETC is used to transfer electron donors to electron acceptors. This process creates
ATP and allows for actions such as extracting energy from sunlight and performing
cellular respiration. Other examples of conserved core processes and features that
evolved and are widely distributed among organisms today include the process of
glycolysis and structural evidence including membrane-bound organelles, cytoskeletons,
and endomembrane systems.
Multiple Choice Question: DNA replication, as shown in the figure provided, is
one process that evolved and is widely distributed among organisms today.
Which answer choice below correctly represents the process of replication?
I.
The bubbles expand laterally as DNA replication
proceeds in both directions
II. The two parental stands separate and form
replication bubbles at the origin or replication
III.
Synthesis of the daughter cells is complete
IV. The replication bubbles fuse
A)
B)
C)
D)
I,II,III,IV
II,IV,I,III
II,I,IV,III
II,I,III,IV
Figure 1.1
Learning Log/FRQ-style Question: The electron transport chain (ETC) is a major
function which all living organisms share to this day. Explain the process of the
ETC as well as why it is needed and what would happen if the ETC did not exist.
(CUES: respiration, combust, NADH, FADH2, electronegative, O2, H2O)
Answer Key- LO 1.16
Multiple Choice Question: DNA replication is one process that evolved
and is widely distributed among organisms today. Which answer choice
below correctly represents the process of replication?
I.
The bubbles expand laterally as DNA replication
proceeds in both directions
II. The two parental stands separate and form
replication bubbles at the origin or
replication
III.
Synthesis of the daughter cells is complete
IV. The replication bubbles fuse
A)
B)
C)
D)
I,II,III,IV
II,IV,I,III
II,I,IV,III
II,I,III,IV
Figure 1.2
Figure 1.1
Answer Key- LO 1.16
Learning Log/FRQ-style Question: The electron transport chain (ETC) is a major
function which all living organisms share to this day. Explain the process of the
ETC as well as why it is needed and what would happen if the ETC did not exist.
(CUES: respiration, combust, NADH, FADH2, electronegative, O2, H2O)
The electron transport chain (ETC) is needed in order for respiration to
occur and is used to help electrons change their energy level slowly so
that they do not combust. Electrons are brought to the ETC by NADH and
FADH2. Once the electrons are in the ETC, they are pumped down their
concentration gradient, with each carrier more electronegative than the
previous one. Oxygen (O2) is the final electron acceptor of the ETC,
forming water (H2O) when it is paired with hydrogen. Once the H+ and O2
combine to form H2O, it leaves the ETC and enters into the next stage of
respiration called chemiosmosis.
LO 2.14: The student is able to use representations and models to describe differences in prokaryotic and eukaryotic cells.
SP 1.4: The student can use representations and models to analyze situations or to solve problems qualitatively and
quantitatively.
Explanation: Domains bacteria and archaea are unicellular organisms that contain prokaryotic cells and have no true
nucleus or membrane bound organelles. Prokaryotic cells contain a nucleoid, which is chromatin bodies that remain
scattered within the cytoplasm and a plasma membrane that encloses the interior of the cell. One long strand of DNA is
present. The prokaryotic cells have smaller ribosomes in comparison to a eukaryotic cell. Prokaryotic cells have a flagella
and cilia (source of movement of the cell towards nutrients or away from toxins) that are “complex”. A prokaryotic cell is
10um in size. Unidirectional transfers of DNA and binary fission (prokaryotic cell division) takes place.
Eukaryotic cells can be in unicellular organisms (Protista, fungi) or multicellular organisms (animals, plants). They contain
membrane bound organelles such as mitochondria (aids in cellular respiration and contains own DNA), lysosomes (contain
enzymes that break down biological molecules), endoplasmic reticulum (transport of materials through the cell), Golgi
apparatus (collects, packages, modifies, and distributes materials throughout the cell), and a true nucleus in which many
chromosomes are present and many more. Eukaryotic cells have a “simple” flagella and cilia that also provide movement for
the cell. A eukaryotic cell is 100um in size. A plasma membrane is present and its function is to enclose the interior of the
cell and regulate what comes in and out. Meiosis (production of haploid gametes) and mitosis (division & replication of
somatic cells) take place within a eukaryotic cell.
MC Question: Shown to the right is an example of a feature that all types of
cells contain (prokaryotic and eukaryotic). What is represented by
the arrow and what is its function?
A. Ribosomes- where protein synthesis takes place
B. DNA- genetic material found inside chromosomes
C. Plasma membrane- where protein synthesis takes place
D. Cytoplasm- functions as a selective barrier for things coming
in/out of the cell
FRQ- There are four major similarities between prokaryotic and
eukaryotic cells. Identify those four similarities and
discuss how they differ within the two types of cells.
ANSWER KEY LO 2.14
MC Question: Shown to the right is an example of a
feature that all types of cells contain (prokaryotic and
eukaryotic). What is represented by the arrow
and what is its function?
A. Ribosomes- where protein synthesis takes place
B. DNA- genetic material found inside chromosomes
C. Lysosomes – break down biological molecules with enzymes
D. Mitochondria- aids in cellular respiration, the “power house”
of the cell
FRQ- There are four major similarities between prokaryotic
and eukaryotic cells. Identify those four similarities and discuss how they
differ within the two types of cells.
The four major similarities include the presence of DNA, ribosomes, a plasma membrane and cytoplasm.
DNA is the genetic material found inside chromosomes. In a eukaryotic cell, there are many chromosomes
found within the nucleus that contain DNA, whereas there is one long DNA strand in a prokaryotic cell. The
DNA is the exact same type in each cell, too. Ribosomes are made up of proteins and subunits and they
translate mRNA into proteins. Plasma membranes is the outermost cell surface, that separates the cell from
the outside environment. Lastly, the cytoplasm is a semiliquid substance that composes the volume of both
prokaryotic and eukaryotic cells.
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
The student can describe a representation or model of natural or man-made evolution in a population. There is a large amount of scientific
evidence that supports the idea that evolution has occurred in all species. Evidence includes homologous structures, which are similar structures
with different functions, which shows signs of common ancestry. In addition, comparative embryology proves the same point with examples
such as post anal tails. Molecular biology also proves this because all life on earth has the same genetic code and dictionary. Another large piece
of evidence are fossils themselves which reflect the gradual change over time. Convergent evolution also serves as proof because although some
organisms do not share a common ancestor, they develop similar structures and features. Biogeography, where similar species tend to be found
in same geographic region, also proves evolution. There is also scientific evidence that supports the idea that evolution continues to occur, which
includes organisms forming chemical resistance in the absence of the chemical, such as pesticides and herbicides. In addition, directional
phenotypic change in a population, such as Grant’s later observations of Darwin’s finches, proves the continuation of evolution.
• What aspect of microevolution is being described in the following model?
There were three species of seals living on Bay Island in 1972. A volcano erupted and destroyed parts of the island.
Seal
Rough-Skinned
Soft-Coated
Albino
Before the eruption
12,000
8,000
5,000
After the eruption
500
3,000
1,500
A. Founder Effect
B. Bottleneck Effect
C. Genetic Drift
D. Selective Mating
E. Natural Selection
• DDT functions by binding to a specific matching site on the membrane of the insect’s nerve cells. When a certain level of DDT binds to the
nerve cell membrane, the nervous system no longer is able to function properly. As a result, the insect dies. Any allele that adversely affects the
binding of DDT to the nerve cell, if it is not lethal or almost lethal, has the potential of conferring DDT resistance to the insect. The other side is
that the allele also interferes with the ability of the cell to bind to other products, causing it to be less effective. As a result, the DDT-resistant
insect is less able to compete in an insecticide-free environment (the normal, natural environment.)
a.) Describe what will happen to the population of insects.
b.) One trophic level above the insect is a bird. Describe what will happen to the bird population.
Answer Key
A. This is an incorrect answer because the Founder Effect is genetic drift in a new colony.
B. This is the correct answer because Bottleneck Effect is where a disaster reduces a population size so that the
surviving population is not representative of the original population.
C. This is an incorrect answer because Genetic Drift is gene pool changes in a small population due to chance.
D. This is an incorrect answer because Selective Mating is where favored alleles are selected for.
E. This is an incorrect answer because Natural Selection is where variability within a population enables some
organisms to be better suited for survival and reproduction.
a.) The population of insects will mutate and become resistant to the intended effect of DDT. At first, the insects who
would not form a resistance would die, but those few who lived would reproduce and pass the mutation on to future
generations. However, the insects’ cells effected by DDT would lose the ability to bind to other products and the insects
would become less able to compete in the natural environment.
b.) Due to biomagnification, the incremental increase in a contaminant's concentration at each level of the food chain,
the population of birds would face a more concentrated dose of DDT and would have to form a resistance to the DDT in
order to survive and continue eating the insects. However, they may avoid the insects altogether and focus on another
source for food, such as seeds, which would potentially cause evolution with a potential change in beak structure.
LO 1.14: The student is able to pose scientific questions that correctly identify
essential properties of shared, core life processes that provide insights into
the history of life on Earth.
SP 3.1: The student can pose scientific questions.
Explanation: In all three domains of life (Archaea, Bacteria, and Eukarya), RNA and
DNA act as carriers of genetic information. Most biologists accept that all life on Earth
descended from self-replicating RNA molecules, an hypothesis known as the “RNA
world hypothesis.” This hypothesis explains the observation that all organisms share
a universal genetic code.
M.C. Question: Which of the following questions provides insight into the history of
life on Earth and can be scientifically verified?
A. Why do organisms share a universal genetic code?
B. When did the first self-replicating RNA molecule emerge?
C. What conditions on prebiotic Earth would have allowed for the emergence of
self-replicating RNA molecules?
D. What properties of RNA molecules make it plausible that they were the
precursors to all life on Earth?
Learning Log/FRQ-style Question: All current life on Earth shares a universal genetic
code. The “RNA world” hypothesis suggests that self-replicating RNA molecules were
the precursors to life on Earth. Describe three properties of RNA molecules that
support this hypothesis. Then, pose a scientific question that provides insight into the
history of life on Earth in relation to the “RNA world” hypothesis.
ANSWER KEY-LO 1.14
Which of the following questions provides insight into the history of the Earth and can be scientifically verified?
A.
B.
C.
D.
Why do organisms share a universal genetic code?
When did the first self-replicating RNA molecule emerge?
What conditions on prebiotic Earth would have allowed for the emergence of self-replicating RNA molecules?
What properties of RNA molecules make it plausible that they were the precursors to all life on Earth?
All current life on Earth shares a universal genetic code. The “RNA world” hypothesis suggests that self-replicating RNA molecules
were the precursors to life on Earth. Describe two properties of RNA molecules that support this hypothesis. Then, pose a
scientific question that provides insight into the history of life on Earth in relation to the “RNA world” hypothesis.
RNA molecules are single-stranded, allowing them to assume a variety of specific three-dimensional shapes, determined
by their nucleotide sequence. RNA molecules with certain base sequences are more stable and have a higher rate of
fecundity, allowing them to survive and replicate, a scenario which would have led to the development of natural
selection on Earth. Some RNA molecules act as catalysts and they are known as ribozymes. A few of these ribozymes
can make complementary copies of RNA, allowing RNA molecules to self-replicate. Both of these properties allowed for
natural selection to take over and diversification to begin.
A good scientific question to ask would be, “What conditions on prebiotic Earth would have favored the substitution of
DNA for RNA as the primary carrier of genetic information?”
•
•
LO 2.32 The student is able to use a graph or diagram to analyze situations or solve problems
(quantitatively or qualitatively) that involve timing and coordination of events necessary for normal
development in an organism.
SP 1.4 The student can use representations and models to analyze situations or solve problems
qualitatively and quantitatively
Explanation: Timing and coordination of specific events are necessary for the normal development of
an organisms and these are regulated by a variety of mechanisms that can be graphed and shown
over a period of time. You can observe cell differentiation that results from gene expression of
different issue specific proteins. Induction of transcription factors during the development results in
sequential gene expression that is can be graphed and expressed as a diagram that the student must
learn to analyze. Students must be able to connect the time it takes for development of an organism
and how it relates to the creation and function of the organism.
M.C. Question :When would memory
cells be produced?
A. Between 36 and 48 days
B. Between 18 and 24 days
C. Between 0 and 6 days
D. Between 30 and 36 days
E. Both C and D
FRQ-Question: Plants produce a certain amount of ATP
in a day and produce more ATP at different time of the
day depending on the amount of sunlight present.
Graph how much ATP a plant would use if it experienced
sunlight throughout the day. Explain why you created
the graph you did.
Antibody (to A) concentration
•
Cell Exposure to
antigen B
Second exposure
4
3 First exposure
2
1
Time (days)
0
0
6 12 18 24 30 36 42 48 54 60
Series 1
Column1
Column2
•
•
•
ATP production percentage
7
6
5
4
3
2
1
When would memory cells be produced?
D. Both C and D
Plants produce a certain amount of ATP in a day and produce more ATP at
different time of the day depending on the amount of sunlight present. Graph
how much ATP a plant would use if it experienced sunlight throughout the day.
Explain why you created the graph you did.
ATP use throughout a day
The amount of ATP
production increases
during the day as
more sunlight
becomes available to
the plan which
allows the plant to
produce more ATP
because
photosynthesis rates
will also be
increased.
0
12:00 AM
6:00am
Series 1
12:00pm
Series 2
Series 3
6:00pm
LO 1.20: The student is able to analyze data related to the questions of speciation and extinction throughout the Earth’s
history.
SP 5.1: The student can analyze data to identify patterns or relationships.
Explanation: Speciation is the appearance of new species over time,
whereas extinction is the dying out of a species. Someone could analyze
new species appearing through the two types of speciation, sympatric
speciation and allopatric speciation. Sympatric speciation is creates new
species through intrinsic changes, like chromosomal changes, and
allopatric speciation is caused by geographic barriers isolating a population
and preventing gene flow. Extinction occurs when species are diminished
because of environmental forces or evolutionary changes. In Figure 1 you
can see the two types of speciation occurring in a population of fish in a
lake, making the orange species split into two different species, the orange
and the blue species.
Figure 1
M.C. Question: Which of the following would be an example of allopatric
speciation that spit up a species of lizards off Lizard Island?
a. The some of the lizards had a change in their genes causing them not to
be able to reproduce properly with the other lizards and after many years
two different species of lizards were formed.
b. Half of the lizards were nocturnal, and half of them were not, therefor
they didn’t mate at the same time. Because of this the lizards were split
into two species.
c. After a big tsunami, Lizard Island was separated by a body of water, into
two different islands, causing the species to separate.
d. Some of the lizards got mad at the other lizards and decided to leave the
island forming two different species of lizards.
Free Response Style Question: You are studying two species of mice in South America. You notice they are fairly similar
and assume they may have originally come from the same species. After doing more research explain two scenarios where
speciation could have been the cause of this species split using both allopatric speciation and sympatric speciation.
Answer Key
M.C. Question: Which of the following would be an example of allopatric speciation that spit up a species of lizards off
Lizard Island?
a. The some of the lizards had a change in their genes causing them not to be able to reproduce properly with the other
lizards and after many years two different species of lizards were formed.
b. Half of the lizards were nocturnal, and half of them were not, therefor they didn’t mate at the same time. Because of this
the lizards were split into two species.
c. After a big tsunami, Lizard Island was separated by a body of water, into two different islands, causing the species to
separate.
d. Some of the lizards got mad at the other lizards and decided to leave the island forming two different species of lizards.
M.C. Explanation: The answer to the multiple choice question is C. After a big tsunami, Lizard Island was
separated by a body of water, into two different islands, causing the species to separate is an example of
allopatric speciation because allopatric speciation is where a species is separated by a geographic barrier,
such as mountains or water.
Free Response Style Question: You are studying two species of mice in South America. You notice they are
fairly similar and assume they may have originally come from the same species. After doing more research
explain two ways that speciation could have been the cause of this species split using both allopatric
speciation and sympatric speciation.
FRQ Answer: After studying these mice, you notice that they may have come from the same species.
Allopatric speciation or sympatric speciation could have been the cause of this species separating. The mice
could have changed due to allopatric speciation if humans built a town on the land where the mice lived,
splitting the mice, and not allowing them to interact with each other, then after many years, the mice
become two different species because they never came in contact with each other. Another way the mice
could have become separate species is through sympatric speciation. Sympatric speciation could have
occurred in this mouse species if the mice all ate one type of seed, but then some of the mice started to eat
another, tastier seed. Since these groups of mice are eating different foods they will not interact as much,
and after many generations, they would have become different species because they will reproduce with the
mice that they are closest to.
LO 1.24: The student is able to describe speciation in an isolated population and connect it to
change in gene frequency, change in environment, natural selection, and/or genetic drift.
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.
Speciation, or the evolution of reproductive isolation and therefore a new species, occurs as
a byproduct of environmental or genetic changes, such as altered gene frequency or
changing selective pressures, that accumulate and prevent gene flow within two or more
portions of a population.
Multiple Choice:
If an isolated population is spread over a large area, with sparse distribution, is speciation more or less
likely to occur than if the same population were densely distributed in a small area?
A. No, because individuals at one end of the large area would have little to no chance of mating with
individuals at the other end, and would experience different selective pressures.
B. Yes, because individuals at one end of the large area would have little to no chance of mating with
individuals at the other end, and would experience different selective pressures.
C. No, because individuals at one end of the large area would have a very high chance of mating with
individuals at the other end, and would experience the same selective pressures.
D. Yes, because individuals at one end of the large area would have a very high chance of mating with
individuals at the other end, and would experience the same selective pressures.
FRQ: Describe two types of evidence
that can be used to indicate the
occurrence of speciation and how
each indicates reproductive isolation.
Figure: demonstrates
speciation within a
population of beetles due
to geographic isolation (a
river).
Answers
Multiple choice: (B)
FRQ: Members of a population in an environment may have access to
different resources. For example, iguanas in one part of a forest may
have only oak trees to live in, while in another part only small shrubs
are present. Many generations later, the tree-dwellers and shrubdwellers meet in a part of the forest home to both trees and shrubs,
but they do not reproduce due to an occurrence of habitat isolation
where the two populations do not interact due to their different
habitats. This habitat isolation is evidence of speciation. Separation of
members of a species can also lead to speciation. For example, some
members of a population of ants may be present on a ship that docks
at a faraway island. The ants disembark and find food on the island,
and their population grows as they develop mating rituals involving
the native berries on the island. Many generations later, another ship
arrives and takes some of the island ants back to the mainland but the
island ants cannot mate with the mainland ants because they no
longer share the same mating rituals, in an instance of reproductive
isolation due to behavioral isolation, evidence of speciation.
LO 1.31 The student is able to evaluate the accuracy and legitimacy of data
to answer scientific questions about the origin of life on earth.
SP 4.4 The student can evaluate sources of data to answer a particular
scientific question.
•
Explanation- In the 1950’s Stanley Miller and Harold Urey were doing experiments to find origin of life on Earth. The
took molecules that may have been major components of the early atmosphere and put them in a closed system. They
used methane, ammonia, hydrogen, and water in their closed system and ran electric currents through to represent
lighting storms that were believed to be a likely occurrence in early earth time. Organic compounds were formed and
amino acids were formed. Amino acids are what are used to make protein. Both of those are needed for cellular life and
they were formed under the conditions that were believed to be the same as the conditions as early earth. This proved the
legitimacy of life forming based off of the conditions there were in early earth.
MC Question- Which biologists were
involved in proving life could come under
the conditions of early life?
A. Hershey/Chase
B. Meselson/Stahl
C. Stanley/Miller
D. Nirenberg/Leder
Free Response Question- What role does
RNA have with the origin of the Earth?
Miller/ Urey experiment
ANSWERS
•
•
•
•
•
MC Question- Which biologists were involved in proving life could come under the conditions of
early life?
A. Hershey/Chase
B. Meselson/Stahl
C. Stanley/Miller
D. Nirenberg/Leder
• Free Response Question- What role does RNA have with the origin of the Earth?
The”RNA world” idea is an idea that states thatin the development of life on the Earth, evolution
based on RNA replication comes before protein synthesis. In early development of life on earth genetic
continuity was assured by the replication of RNA and genetically encoded proteins were not involved
as catalysts. One assumption is that at some time in the evolution of life, genetic continuity was
assured by the replication of RNA. The notion of the RNA World places emphasis on an RNA molecule
that catalyzes its own replication. Such a molecule must function as an RNA-dependent RNA
polymerase, acting on itself to produce complementary RNAs.
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: Positive and negative feedback cycles are responsible for homeostatic regulation. A stimulus is acted upon with various
inputs and or outputs that trigger a response. Examples of homeostatic mechanisms are metabolism regulation, thermoregulation and
hormonal secretions. These mechanisms that are vital to an organism's ability to maintain an efficient balance with its environment can
be linked to common ancestry of a species due to specific monomers and lipids, the eight essential amino acids, proteins, etc. These
“building blocks of life” that all living organisms share can be traced back to the protobions that colonized early earth. The most
important homologous structure between the earth’s simple and early life forms and the complex living organisms today are the
membrane bound organelles that are crucial to the cyclical functioning of feedback response to an organism's environment. On a larger
scale, species populations as a whole have adapted best to suit their environment, and while gene flow may be altered, the way that an
organism maintains homeostasis in it’s present environment can be attributed to a common ancestral species. The similarities in
homeostatic mechanisms that arise from divergent evolution of a common ancestor to a modern day species is an evident phenomena
that can reflect continuity due to the shared desire to use the “basic building blocks of life” in adaptive measures to specific
environmental conditions.
MC Question: It is evident that humans have evolved from apes and we share a
common ancestor to the modern day chimpanzee. Which homeostatic mechanism would
not support common ancestry between the two species?
A) Both the chimpanzee and human have similar immune system responses to viral
infections due to the production of antibodies.
B) Similarities in the regulation of blood osmolality in the kidneys.
C) A gestation period of around 9 months
D) Courtship behaviors that lead to both species desiring to produce viable offspring
E) Hormone regulation that results in similar stage shifts between adolescence,
puberty and adulthood.
Free Response: Explain the importance of a specific
membrane bound organelle highlighting on how it contributes
to homeostasis in the human body. Then describe a
homeostatic process and it’s location, and connect that to a
specific feedback cycle. Then relate the importance of this
process to the need to utilize the “building blocks of life” that
are reflective of human evolution from a more simple
lifeform.
Answer Key- LO2.25:
MC Question: It is evident that humans have evolved from apes and we share a common ancestor to the modern day chimpanzee.
Which homeostatic mechanism would not support common ancestry between the two species?
A) Both the chimpanzee and human have similar immune system responses to viral infections due to the production of antibodies.
B) Similarities in the regulation of blood osmolality in the kidneys.
C) A gestation period of around 9 months
D) Courtship behaviors that lead to both species desiring to produce viable offspring
E) Hormone regulation that results in similar stage shifts between adolescence, puberty and adulthood.
Answer: D. The answer is D because although behavioral patterns are fairly similar between the two species, it is not a definitive
example that the two have arisen from a common ancestor. The other answers are correct because they are specific autonomic
mechanisms that are regulated by specific organelles, kidneys and pituitary gland respectively. Both chimps and humans share a high
percentage of identical DNA (98%) which has resulted in the two species having similar genes that can be turned on and off by specific
stimuli.
Free Response: Explain the importance of a specific membrane bound organelle
highlighting on how it contributes to homeostasis in the human body. Then describe a
homeostatic process and it’s location, and connect that to a specific feedback cycle. Then
relate the importance of this process to the need to utilize the “building blocks of life” that
are reflective of human evolution from a more simple lifeform.
The pancreas is an organ that is responsible for regulating blood glucose levels. Homeostasis
can become imbalanced when there is an excess amount of solutes in the blood from food
consumption. Glucose regulation occurs in the pancreas and in the liver. When blood glucose
levels rise, the pancreas is triggered to secrete insulin into the blood stream, the increase of
insulin results in the extracellular storage of glucose as glycogen. This is an example of a
negative feedback due to a stimulus, increased glucose in the blood stream, and a response,
secretion of insulin to store glucose as glycogen as a mechanism to return back to
homeostasis. The regulation of glucose is an evolutionary process that has evolved over time
since the creation of carbohydrates. Carbohydrates evolved from simple monomers to
polymers during abiotic synthesis of organic compounds on early Earth. Carbohydrates are a
source of energy and they are essential for maintaining homeostasis in an organism due to the
production of energy being necessary for regulation pathways.
LO 1.22: The student is able to use data from a real or simulated population(s), based on graphs or models of types of selections, to
predict what will happen to the population in the future.
SP 6.4: The student can make claims and predictions about natural phenomena based on scientific theories and models.
Explanation: Evolution is the process of speciation, the change of a species genetic makeup over time by way of natural
selection. Individuals with favored characteristics for their environment get to pass along their genes to the next generation.
These favored traits help create new species, better suited for their environment. Environmental changes, catastrophic
events such as volcanoes, earthquakes, or tsunamis as well as human caused events like pollution, can cause a change in
the gene pool of a species. DNA mutations are also sources of genetic variation. Evolution can be charted on a cladogram,
showing when species drifted from another based on physical features they developed at a certain point in time. There are
three different types of natural selection including directional selection, stabilizing selection, disruptive selection. Graphs and
models help us predict what is most likely to happen, within a population based on that data. Directional selection is when a
population’s trait distribution shifts from one extreme to another. Stabilizing selection is when the extreme traits of a
population are selected against, stabilizing trait distribution, resulting in a more narrow graph. Disruptive selection is when
the population favors the two extremes, mostly homozygous
dominant or recessive, few heterozygotes.
Multiple Choice Question: From the figure on the right,
which graph correctly displays in order: directional,
stabilizing, and disruptive selection.
A) Graph A, Graph B, Graph C
B) Graph C, Graph B, Graph A
C) Graph A, Graph C, Graph B
D) Graph B, Graph, A, and Graph C
Learning Log/FRQ-style Question: Also using the
graph to the right, describe the gene pool resulting from
each type of natural selection and and what
we can expect from each population.
A
B
C
Multiple Choice Question: From the figure on
the right, which graph correctly displays in
order: directional, stabilizing, and disruptive
selection.
A) Graph A, Graph B, Graph C
B) Graph C, Graph B, Graph A
C) Graph A, Graph C, Graph B
D) Graph B, Graph, A, and Graph C
Learning Log/FRQ-style Question: Also using
A
the graph to the right, describe the gene pool resulting from
each type of natural selection and and what
we can expect from each genetic population.
B
C
All three types of selection will result in a decrease of the gene pool. Directional selection will
result in a either a more homozygous recessive or dominant population but not both. These
populations have lost certain traits of the allele not present, resulting in a less variance.
Stabilizing selection results in a heterozygous population. The genetic pool still contains both
alleles so genetic variance is possible in generations to come if selected for. Disruptive selection
results in a homozygous gene pool, containing both dominant and recessive with very few
heterozygotes. Genetic variance is possible as well because both alleles are present in the
population.
LO 2.38: The student is able to analyze data to support the claim that responses to information and communication of
information affect natural selection.
SP 5.1: The student can analyze data to identify patterns or relationships.
Explanation: Natural selection is differential success in the reproduction of different phenotypes resulting from the interaction of
organisms with their environment. For plants there are two factors that response to info. and communication of info. affecting
natural selection: 1. phototropism, changes in the light source to differential growth, resulting in maximum exposure of leaves to
light for photosynthesis and 2. photoperiodism, changes in the length of night regulate flowering and preparation for winter. They
are crucial to natural selection because plants are sensing the phototropism using phytochromes (plant pigment) to regulate the
time of flowering based on the length of day and night (photoperiodism) and to set circadian rhythms which has chosen over time by
natural selection triggering when to flower. For animals there are many factors that response to info. and communication of info.
affecting natural selection. Behaviors in animals are triggered by environmental cues and are vital to reproduction, natural selection
and survival. Some of those behaviors are hibernation (winter), estivation (summer), migration, and courtship that attribute to
natural selection in animals. As well, as many cooperative behavior within or between populations that contributes to the survival
for the population. Examples of cooperative behavior that contributes to the survival of the populations include: niche and resource
partitioning, availability of resources leading to fruiting formation in fungi and certain types of bacteria, mutualistic relationships
(lichens; bacteria in digestive tracts of animals; mycorrhizae , and biology of pollination.
M.C. Question:
In the figure below illustrates the examples of three different ways natural selection change a population, which of the following
mode of natural selection does not accurately match with the example provided?
A) Stabilizing selection: Robins typically lay four eggs, larger clutches may result in malnourished chicks while smaller clutches may
result in no viable offspring.
B) Directional selection: Light-colored peppered moths are better camouflaged against a pristine environment; likewise, dark-colored
peppered moths are better camouflaged against a sooty environment.
C) Diversifying selection: The gray and Himalayan (white and gray) rabbits are at a disadvantage of blending with the rocky
environment than the white rabbits.
D) All of the following answers are correct.
Learning Log/FRQ-style Question:
Without natural selection there would not adaptive behaviors, which
means animals would not be able to survive in the constantly changing
environment. In the two diagrams provided (mode of natural selection
and Darwin’s finches) define the three modes of natural selection and
apply Darwin’s finches with one of the three modes with explanation
that supports your example. Why is “survival of the fittest” misleading?
Answer Key–LO 2.38
M.C. Question:
In the figure below illustrates the examples of three different ways natural selection change a population, which of the following
mode of natural selection does not accurately match with the example provided?
A) Stabilizing selection: Robins typically lay four eggs, larger clutches may result in malnourished chicks while smaller clutches may
result in no viable offspring.
B) Directional selection: Light-colored peppered moths are better camouflaged against a pristine environment; likewise, dark-colored
peppered moths are better camouflaged against a sooty environment.
C) Diversifying selection: The gray and Himalayan (white and gray) rabbits are at a disadvantage of blending with the rocky
environment than the white rabbits.
D) All of the following answers are correct.
The correct answer is C. In the data provided, indirectly defines each of the following modes of natural selection . The student just
need to analyze the figure given and then apply it to the question. In this case, the student is to find the following mode of natural
selection that does not match correctly with the example . Diversifying selection is natural selection that favors individuals on
both extremes of a phenotypic range over intermediate phenotypes. C is incorrect because the gray and Himalayan rabbits are at
an advantage of blending in with the rocky environment since the white rabbits would be more noticeable and does not match up
with the definition of diversifying selection.
Learning Log/FRQ-style Question:
Without natural selection there would not adaptive behaviors, which
means animals would not be able to survive in the constantly changing
environment. In the two diagrams provided (mode of natural selection
and Darwin’s finches) define the three modes of natural selection and
apply Darwin’s finches with one of the three modes with explanation
that supports your example. Why is “survival of the fittest” misleading?
Stabilizing selection- favors intermediate variants by acting against extreme phenotypes
Ex. Along the line of intermediate trait that increases chances of survival for the finches... (black beak, gray beak, white beak)
Disruptive selection-favors individuals on both extremes of a phenotypic range over intermediate phenotypes
Ex. Along the line of both extremes of a trait that increases chances of survival for the finches...(black beak, gray beak, white beak)
Directional selection-favors individuals at one end of the phenotypic range... (black beak, gray beak, white beak) or
(black beak, gray beak, white beak)
Ex. Along the line of one of the end that has a more favorable trait that increases survival for the finches
“Survival of the fittest” is misleading because “fittest” usually mean the strongest but in this cause it is not it should be
“reproduction” of the fittest. Natural selection is differential reproduction not just survival.