Name: ___________________________________________
ECOLOGY:
What is Ecology?
Ecology is the study of interactions of living organisms with one another and with
their environment. The environment consists of biotic (living organisms) factors
and abiotic (non-living) factors.
Scientists hypothesize that oxygen began to accumulate in Earth’s atmosphere
after the appearance of living things with the ability to do what biochemical
process? Explain why.
Photosynthesize. Oxygen is released into the air as a byproduct of
photosynthesis.
Organize the environment into a hierarchy of levels, starting with the Biosphere.
Biosphere, biome, ecosystem, community, population, individual organism
What is a Biome? List the 8 Biomes.
Biomes are the various regions of our planet which can best be distinguished by
their climate (temp. & rainfall), wildlife and plant life. – Tundra, Desert, Taiga
(Boreal Forest/Coniferous Forest), Deciduous forest, Grasslands (Prairie, Steppe
and Savannas)
Marine & Freshwater.
What is a feature of a stable ecosystem?
Constant supply of energy; stable weather conditions (little pollution); Stable
populations (reasonable fluctuations) - For example, in a stable ecosystem, the
populations of predators influence the populations of the prey
What are the main types of relationships among organisms in an ecosystem?
Mutualism (+/+), Parasitism (+/-), Commensalism (+/0) & Predation (+/-)
For example: Some crocodiles let small birds enter their mouths to pick bits of
food from between their teeth. The crocodiles get clean teeth, while the birds get
an easy meal.
Organisms undergo constant chemical changes as they maintain an internal balance
known as __________________. homeostasis
What is an autotroph? A heterotroph? How do each of these relate to producers,
consumers and decomposers?
Autotroph - organism that makes organic compounds (glucose) from inorganic
sources (CO2 & H2O). Plants, some bacteria, and some protista make their own food
using light energy. – PRODUCERS!
Heterotroph - They obtain their organic compounds (food) by consuming other
organisms.
Almost all animals (CONSUMERS) and fungi (DECOMPOSERS) are heterotroph and some Protista and bacteria.
***(Note: all food molecules ultimately come from autotrophs)***
Think of the Heterotroph as the Consumer in the food chain and the Autotroph as
the producer in the food chain. They both work and need each other...ultimately
seen as one of the many balances of nature.
What is Biodiversity? Which Biome is considered to have the greatest
biodiversity?
Biodiversity is the variety of life.
For example: Cutting down a rain forest and planting agricultural crops, such as
coffee plants, would result in a decrease in biodiversity.
The Rain Forest Biome is the biome with the most biodiversity
What factors contribute to exponential population growth?
Exponential population growth is when the birth rate is
constant over a period of time and isn't limited by food or
disease.
What are biotic and abiotic factors of an ecosystem? Name a few.
Biotic factors are the living parts of an ecosystem – i.e. the animals, plants and
microorganisms.
Abiotic factors are the non-living parts of an ecosystem – i.e. water, sunlight,
temperature, soil acidity.
What is the difference between a food chain and food web?
The food chain follows energy transfer through a single path as animals eat each
other, and a food web shows how plants and animals are interconnected by
different paths.
What is an Energy Pyramid? What happens to the amount of energy as it moves up
the pyramid? About how much energy is transferred from trophic level to trophic
level in an ecosystem?
An ecological pyramid (also trophic pyramid or energy pyramid) is a graphical
representation designed to show how energy is passed from each trophic level in a
given ecosystem.
**Energy decreases, only as you move UP the pyramid**
About 10% - At each level of the food chain, consumers convert only about 10% of
the chemical energy in their food to their own organic tissue (the ten percent law).
The other 90% is used in the life processes to maintain the organism and converted
to heat.
What is a niche? Can two organisms share the same niche?
A niche describes the part an organism plays in the environment, including what
it needs and what it provides. Two organisms cannot share the same niche. They
can only occupy the same habitat, not niche. If niches overlap – species
COMPETE with each other
But - Two closely related species of birds live in the same tree. Species A feeds
on ants and termites, while species B feeds on caterpillars. The two species
coexist successfully because they compete less for food.
What are decomposers? What is their role in an ecosystem? List two examples.
Decomposers are organisms that break down dead or decaying organisms, and in
doing so carry out the natural process of decomposition.
Decomposers are an essential component of any ecosystem. Their main role is to
recycle nutrients in dead organisms and their wastes.
Most decomposers are bacteria and fungi.
Name several human actions which are currently affecting the condition of Earth
today.
exploding human population
technology has increased the amount of carbon dioxide in the air
thinning ozone layer
climate change
Consumption has depleted natural resources
What affect do these actions have on the equilibrium of an ecosystem?
In general - human actions disrupts the equilibrium in ecosystems.
Name the primary reason humans have such an impact on an ecological community?
Human s can modify their environment through technology (transportation,
energy & water purification plants, communication devices, sanitation devices...
What is the primary source of energy for all food chains?
SUN
Describe the steps of the water Cycle.
Condensation (water vapor cools and becomes liquid – clouds), evaporation (water
becomes a gas), precipitation (water falls to earth in various forms), run-off (water
flows to other water – seeping into the ground or collecting as larger bodies of
water)
What is the carbon – oxygen cycle and how do these chemicals cycle through the
environment?
Plants take in carbon dioxide during
photosynthesis. Plants use the carbon
dioxide to make food. During
photosynthesis, plants release oxygen into
the air. Consumers take in oxygen from the
air. They also give off carbon dioxide
during cellular respiration. Dead plants and
animals give off carbon dioxide as
decomposers assist in their decay.
Producers add oxygen to the air and
remove carbon dioxide to the atmosphere. Consumers add carbon dioxide to the
atmosphere and remove oxygen. Decomposers add carbon dioxide and nitrogen back
into the air.
EVOLUTION:
What is Evolution? How do factors like variation, mutation and chance events
influence Evolution?
Evolution is the change in the way a population looks and/or behaves over many
generations (usually millions of years).
Natural selection (Natural Variations these have to be inheritable, competition,
reproduction)
For the rest of us, sex introduces variation into a population.
If it weren't for mutation constantly introducing new versions of genes into the
population, the genetic variation of the population would become extremely low, and
the population wouldn't be able to evolve to adapt to changing conditions.
Mutation results in variations that commonly influence the evolution of sexually
reproducing species.
For example: Thousands of years ago, giraffes with short necks were common
within giraffe populations. Nearly all giraffe populations today have long necks. This
difference is due to a mutation in the DNA controlling neck size occurring in the
reproductive cells of a giraffe.
What is a fossil? What can it tell us about evolution?
A fossil is the preserved remains of animal or plant: the remains of an animal or
plant preserved from an earlier era inside a rock or other geologic deposit, often as
an impression or in a petrified state
Fossils tell us several things. By examining them, we can see the structure of
animals in early times and how they probably lived and when they lived.
For example, Scientists believe that a dinosaur known as a hadrosaurus was a
plant eater because the fossilized teeth of the hadrosaurus are flat like the
teeth of modern herbivores.
What are analogous and homologous structures and how do they relate to
evolution?
ANALOUGOUS STRUCTURES: Structures that serve the same purpose, but are
built very differently. They arise in organisms that are NOT related to each other,
but live in environments where they have similar conditions and similar traits are an
advantage. Some examples of analogous structures are: wings of birds and insects,
the streamlined bodies of seals and penguins. They are different in their internal
anatomy, because they are not a result of common ancestors.
HOMOLOGOUS STRUCTURES: Structure that may differ in function but that
have similar anatomical structure, presumably because the organisms that possess
them have descended from common ancestors. This suggests that all animals
started out from common ancestors and, through natural selection, were modified
to perform different functions. Some examples of homologous structures are: Bat,
bird, and pterodactyl wings, Seal and dolphin flippers, Sheep and dog leg bones,
Shrew and human arm bones.
Who was ‘Jean Lamark’ and what is his connection to Evolution? (Think ‘Acquired
Traits’)
He proposed a theory is which he believed that traits acquired during an organism’s
lifetime due to environmental pressures, for example, could be passed down to their
offspring – Remember the example of the giraffe and neck size…
What is a mutation? How do mutations affect evolution? Why is variation
important to evolution?
A mutation is a sudden change in the genetic material of an organism.
If a mutation causes a new trait to appear in a population and that trait is
favorable, then that organism lives and passes that trait on.
If a mutation cause and unfavorable trait, that organism will die out.
Therefore, over many generations, the frequencies at which those traits occur
within a population will slowly change.
What is genetic variation?
Genetic variation is the genetic differences there are within populations or species.
For example, a population with many different alleles for a specific trait at a locus
may be said to have a lot of genetic variation for that trait.
Genetic variation is essential for natural selection to operate since natural selection
can only increase or decrease the frequency of alleles already in the population.
What is Natural selection? How does Natural Selection influence the frequency of
adaptive traits in a population?
Natural selection, simply put, is descent with modification.
It was an idea of Charles Darwin and Alfred Wallace, and is sometimes called the
survival of the fittest. Darwin chose the name as an analogy with artificial
selection (selective breeding).
Natural selection is the process where organisms with favorable traits are more
likely to reproduce. In doing so, they pass on these traits to the next generation.
Over time this process allows organisms to better adapt to their environment. This
is because the frequency of genes for favorable traits increases in the population.
What is artificial selection?
Long before Darwin and Wallace, farmers and breeders were using the idea of
selection to cause major changes in the features of their plants and animals
over the course of decades. Farmers and breeders allowed only the plants and
animals with desirable characteristics to reproduce, causing the evolution of
farm stock. This process is called artificial selection because people (instead of
nature) select which organisms get to reproduce.
For example - When a breeder allows only the strongest and fastest horses to
reproduce, she is practicing artificial selection.
What is selective breeding? What is the benefit of this type of selection?
Selective breeding is sometimes referred to as artificial selection. This is when humans
select (instead of nature) which organisms to breed together based on the traits we want
passed down. The benefit is we can get organisms that suit our purposes or do/achieve
something specific: frost resistant tomatoes, different breeds of dogs, crops that are
bigger, etc.
PROTEIN SYNTHESIS:
What is the main function of DNA? How is DNA used in protein synthesis?
DNA (deoxyribonucleic acid) is a nucleic acid that controls the cellular functioning.
The DNA contains information for protein synthesis in cells. DNA controls the
resulting mRNA sequence, which controls the sequence of amino acids and thus the
protein.
What is protein synthesis? What are the steps of transcription and translation?
Protein Synthesis is the process in which cells build proteins. Transcription &
Translation is the multi-step process, beginning with transcription and ending
with translation.
Simply stated… DNA ---> RNA ---> protein
1.
2.
3.
4.
5.
mRNA nucleotides ‘transcribe’ the complementary DNA message (Transcription)
mRNA leaves the nucleus
mRNA attaches to the ribosome
tRNA ‘translates’ the mRNA codon (Translation)
amino acids are bonded together
Complete a strand of mRNA from a DNA template – for example: A-G-C-T-C-A-G
mRNA: ____________ U-C-G-A-U-C
What is a clone? What genetic comparisons can be made between the clone and its
parent?
a plant, animal, or other organism that is genetically identical to its parent and has
the same number of chromosomes as the parent.
For example, a carrot plant that was cloned from another carrot cell would have the
same number of chromosomes with the same genes as the parents
Proteins are formed from monomers (subunits) called?
amino acids
What is RNA? What are the three main types of RNA we’ve discussed?
RNA is a nucleic acid with a sugar-phosphate backbone, attached to nitrogenous
bases. RNA conatins the sugar ribose .
mRNA
tRNA
mRNA
What is a codon? Anticodon? What molecule can they be found on?
Codon – a sequence of three bases found on mRNA
Anticodon – a sequence of three bases found on tRNA that is the compliment to the
codon and its complimentary amino acid.
How many nucleotide bases make up a codon?
three bases
For example: A strand of mRNA that is 450 bases long will produce a protein
containing approximately how many amino acids?
150
GENETICS:
Who was Gregor Mendel? What was his contribution to genetics?
Gregor Mendel was an Austrian Monk, who after his work with garden pea plants,
discovered the processes at work when traits are passed from one generation to
the next.
He also showed that the inheritance of traits follows particular laws, which were
later named after him.
Mendel is considered the "Father of Genetics."
What is a gene and where is it found?
A gene is a piece of DNA that codes for a characteristic by coding for a protein..
Genes are found on structures called chromosomes – genes and chromosomes are
made of DNA
What is an allele?
A version of a gene that codes for a specific trait.
Define the following genetic terms: Dominant & Recessive, Homozygous and
Heterozygous; genotype and phenotype.
Dominant – the allele that is expressed more often and has the ability to mask the
presence of another allele for the same gene.
Recessive – the allele that is expressed less often because it can be masked by the
presence of other alleles for the same gene.
Homozygous – having two identical alleles for a gene (homozygous dominant or
homozygous recessive).
Heterozygous – having two different alleles for a gene, usually resulting in the
dominant trait being expressed.
Genotype – the genetic makeup of an organism, the alleles an organism has
inherited.
Phenotype – the physical expression of an organism’s genotype; the traits an
organism has based upon the alleles it has inherited.
Define the following patterns of inheritance:
Co-dominance, Incomplete Dominance, Sex-linkage, Multiple allele traits…
Incomplete : neither allele completely covers the other so the traits blend or mix;
heterozygous phenotype is intermediate of two homozygous phenotypes
example: flower color (Red X White = Pink)
sex-linked : Traits that are controlled by genes located on the sex chromosomes in
humans the X chromosome
example: hemophilia and color-blindness
co-dominance: in heterozygotes, both phenotypes are expressed AT THE SAME
TIME because both alleles are equally dominant.
example: ABO blood group - AB bloodtype
multiple alleles : some genes have more than two alleles available in the population;
each organism still only inherit two (there are just more options)
example: ABO blood group alleles - (three alleles)
Ashley has attached earlobes, which are recessive. Her mother and father both
have free earlobes, which are dominant. Complete the Punnett Square below to help
explain how Ashley inherited attached earlobes?
E
E
e
e
EE
Ee
Ee
ee
The trait for colorblindness (Xb) is a recessive, sex-linked trait and normal vision
(XB) is dominant. If a female who is heterozygous for colorblindness has children
with a man who has normal vision, what percent of their male children would be
expected to be color blind? Complete the Punnett Square below.
XB
Xb
X
XB XB
XB Xb
Y
XB Y
Xb Y
B
We would expect that 1 of
the 2 male children to be
colorblind. This means that
50% of the MALE children
would be expected to be
colorblind.
Be able to complete a Punnett Square backward. Use the example below to
identify the genotype of the parents.
T
t
T
t
T T
T t
T t
t t
How is the genotype expressed in the inheritance pattern of incomplete
dominance?
Incomplete Dominance is a type of inheritance in which one allele for a specific
trait is not completely dominant over the other allele. This results in a combined
phenotype (expressed physical trait).
For example, if you cross pollinate red and white snapdragon plants, the
dominant allele that produces the red color is not completely dominant over the
recessive allele that produces the white color. The resulting offspring are pink.
R
R
r
r
Rr
Rr
Rr
Rr
What is this figure below and what information can you obtain from it?
Karyotype: Some information you can obtain from a karyotype – Sex
(male/female); identify and evaluate the size, shape, and number of
chromosomes in a sample of body cells.
What is ‘Recombinant DNA Technology’? What is an example of how it is used?
A series of procedures used to join together (recombine)
a human DNA segment with that of bacterial genetic
material. Human insulin is produced via Recombinant DNA
technology.
PHOTOSYNTHESIS & CELLULAR RESPIRATION:
What is ATP? Where is the energy stored in this molecule? How is energy
released?
ATP (adenosine triphosphate) is a molecule that cells use for energy. The energy is stored
in the bonds that link the phosphates. To release energy, the bond that holds the third
phosphate is broken. To store energy, that phosphate is reattached and a bond is created.
What is cellular respiration? List and briefly explain the steps of Cellular
respiration (energy producing). (REMEMER - identify the organelle where CR takes
place).What is the simplified chemical equation?
Cellular respiration is the process by which food is broken down by the body's
cells to produce energy, in the form of ATP molecules.
**Simply – the process cells use to release the energy stored in food.
There are two main stages of cellular respiration:
1) Glycolysis (splitting of glucose – happens in cytosol – happens with or without
O2)
2) Aerobic Respiration (takes place in the mitochondria and makes a LOT of
ATP) or Anaerobic Respiration (Fermentation) (this makes 0 ATP and is
usually done by microorganisms).
The simplified formula for aerobic cellular respiration is:
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (as ATP)
For example, be able to identify “X”.
What do burning fossil fuels and the process of cellular respiration have in
common?
Both break down carbon-containing compounds for energy
What is photosynthesis? List and briefly explain the steps of Photosynthesis
(REMEMER - identify the organelle where photosynthesis takes place) (energy
storing). What is the simplified chemical equation for photosynthesis?
Photosynthesis is how plants use sunlight, air and water and convert them into
glucose. That glucose then feeds the plants and provides oxygen for people and
animals to breathe and energy in the form of glucose for them to eat.
Photosynthesis takes place inside organelles called chloroplasts.
6CO2 + 6H2O + Energy (in the form of Sunlight) →C6H12O6 + 6O2