Download Practice Final Answer Key - Mercer Island School District

Biology Practice Final: 1st Semester
1.
What does it mean for a set of data to be reliable?
Reliable data is consistent, with the outcomes within each
group being close in value.
2.
What does it mean for a set of data to be valid?
Valid data is accurately measuring the intended outcome.
3.
In order to ensure the reliability of an experiment, a researcher should
A.
B.
C.
D.
4.
In order to ensure the validity of an experiment, a researcher should
A.
B.
C.
D.
5.
be sure to have only one manipulated variable
have multiple samples or repeated trials
avoid sample bias
both A and C
be sure to have only one manipulated variable
have multiple samples or repeated trials
avoid sample bias
both A and C
A group of students design an experiment to test whether the color of
light shining on a plant affects the rate of photosynthesis. In order to
measure the rate of photosynthesis, they measure the number of
bubbles of oxygen gas given off by aquatic plants. In this experiment,
what is the manipulated (independent) variable?
A. the number of bubbles given off
B. the color of light
6.
C. the size of the plants
D. none of the above
For the experiment in #5, what is the responding (dependent) variable?
A. the number of bubbles given off
B. the color of light
C. the size of the plants
D. none of the above
7.
For the experiment in #5, what is a controlled variable?
A. the number of bubbles given off
B. the color of light
8.
The average rainfall in a lake is a(n) __________________ and the size of
a minnow (fish) population is a(n) ____________________ .
A. biotic factor, abiotic factor
B. biotic factor, biotic factor
9.
C. the size of the plants
D. B and C
C. abiotic factor, biotic factor
D. abiotic factor, abiotic factor
The difference between an organism’s habitat and its niche is that
A. habitat only includes the physical space it lives in and niche
includes its role in the ecosystem.
B. niche only includes the physical space it lives in and habitat includes
its role in the ecosystem.
C. habitat and niche are the same
D. habitat is where an organism lives and niche is where a population
lives
10.
The first trophic level is always
e
A. a decomposer
B. an herbivore
11.
C. an autotroph
D. a scavenger
The difference between a community and an ecosystem is
A. a community only includes all the organisms in a region, and
ecosystem also includes the abiotic factors.
B. an ecosystem only includes all the organisms in a region, and
community also includes the abiotic factors
C. community and ecosystem are the same
D. a community only includes all the organisms of one species and an
ecosystem includes all living things
12.
Explain why decomposers are important in an ecosystem.
Decomposers recycle nutrients into the ecosystem so that the
nutrients can be used by other organisms.
13. Explain what an energy pyramid is. What type of organism is always at
the base (widest part) of a pyramid? Explain why less energy is available
at higher levels of the pyramid and why this is still consistent with the
Law of Conservation of Energy.
Energy pyramids show the decrease in available energy as you move up a
food chain. The base of an energy pyramid is always the autotroph-
which stores the greatest amount of total energy. Not all of the energy is
based on to the next step in the food chain- much of it is lost as heat, so
each step in the food chain must consume a greater amount of the
previous level.
14. In an ocean food chain, algae is eaten by zooplankton. Krill feeds on
zooplankton. The krill is eaten by penguins and orca whale prey on
penguins. Draw out the food chain with the correct direction of the
arrows.
Arrow goes toward the organism that consumes the other organism, following
the flow of energy in the food chain.
Algaezooplanktonkrillpenguinsorca s
15. In the food chain above, which species would be most affected by DDT (a
toxin) in the ecosystem? Explain why.
If a toxin bioaccumulates (stays in body tissue) it will be
biomagnified through the food chain (top consumer most affected).
Because of the energy pyramid, each level in the food chain must
eat a greater amount of the previous level.
For example, one pound of orca would need to be supported by 10
lb of salmon, which would be supported by 100 lb of smaller fish
which would be supported by 1000 lb of kelp. Thus any toxins such
as DDT would be more concentrated in the top consumer.
The toxins
become more
concentrated in
a smaller
amount of
biomass as you
move up the
energy
pyramid.
16. In the carbon cycle, carbon dioxide in the atmosphere is incorporated into
organic molecules (sugars and other molecules in living things) through
_____________ .
A. photosynthesis only
B. combustion and respiration
C. photosynthesis and combustion
D. respiration only
17. In the carbon cycle, carbon dioxide is returned to the atmosphere through
___________ .
A. photosynthesis only
B. combustion and respiration
C. photosynthesis and combustion
D. respiration only
18. A symbiotic relationship in which both species benefits is called
A. parasitism
C. commensalism
B. mutualism
D. competition
For the questions below, identify which roles each organism plays in the
following food chain.
Rose  Aphid Lady bug Robin Fox Bacteria
List ALL of the terms that apply. This means that each organism can be labeled
with more than one letter and that letters can be used more than once.
19.
20.
21.
22.
23.
24.
Rose _____A, C____
Aphid ___B, D, E_____
Lady bug __B,D, F_______
Robin ___B, D, F_____
Fox ____B, D, F___
Bacteria ___B, D, G_____
A.
B.
C.
D.
E.
F.
G.
autotroph
heterotroph
producer
consumer
herbivore
carnivore or omnivore
decomposer
25. Describe the process of natural selection.
Natural selection is the process that causes change in the gene pool
of a population (all of the genes in the population) over time.
Natural selection requires there to be heritable variation (heritable
= able to be inherited) and differential reproduction (differences in
which members of a population survive and reproduce due to the
struggle for survival).
The Process of Natural Selection: Individuals within a population
that have favorable traits are more likely to survive and reproduce
so more of these favorable genes will be more likely to be passed
on. Over time many generations there will be an increase in the
favorable genes in the gene pool. (Also known as survival of the
fittest- where fittest= reproductive success.)
26. Variation is a prerequisite for natural selection to occur.
A. What process produces variation in a population? Explain.
Mutations produce changes in genes which creates heritable
variation.
B. Why is this often a limiting factor in a populations ability to adapt to its
environment?
Mutations occur randomly. Favorable variation must be present in
the population.
27. When distantly related species develop similar adaptations because they
have similar niches and therefore similar natural selection pressures, is called
_____________ . (For example, whales are mammals that are more distantly
related to fish yet have similar adaptations to live in water.)
A. coevolution
B. convergent evolution
C. divergent evolution
D. adaptive radiation
28. If two populations of a species are geographically isolated, such as two
deer populations on either side of a mountain range, and over time these
populations change so much to adapt to their different environments that the
populations can no longer interbred, the process is called
A. coevolution
B. convergent evolution
C. divergent evolution
D. adaptive radiation
Divergent Evolution
Divergent evolution occurring
after two populations of pines
become geographically isolated
29. Explain why DNA and protein sequencing is considered more reliable than
anatomical comparisons when determining how closely related two species are.
Distantly related species that live in similar environments or occupy
similar niches in an ecosystem face similar natural selection
pressure and therefore may have similar adaptations. This process is
called convergent evolution. For example, sea mammals like orcas
have a similar appearance to fish even though they are distantly
related. So comparing the anatomical similarities of two species to
determine how closely related they are may be misleading.
Correct Answer: D
Correct Answer: C
9
To find the population density,
divide the number of organisms
by the area.
33. A substance with a pH of 3 is
A. Basic
B. Acidic
C. Neutral
D. Inert
34. Water
A. takes more energy to heat a pound of water by 1 °C than it does for
most other substances
B. takes less energy to heat a pound of water by 1 °C than it does for
most other substances
C. resists temperature changes, and can moderate temperatures.
D. Both A and C
E. Both B and C
35. Polysaccharides are a type of _______ and are composed out of ______ .
A. proteins, amino acids
B. carbohydrates, sugars
C. carbohydrates, amino acids
D. lipids, fatty acids
36. Which macromolecule has a 1:2:1 ratio of carbon to hydrogen to oxygen?
A. protein
B. lipids
C. carbohydrates
D. nucleic acids
For example: Glucose = C6H12O6
37. What are the building block of proteins?
A. amino acids
B. nucleotides
C. sugars
D. fatty acids
38. Cellulose is a _______________ whose main function is _______.
A.
B.
C.
D.
carbohydrate, energy storage
carbohydrate, structural support in plants
protein, energy storage
protein, catalyze chemical reactions
39.
What type of macromolecule are enzymes composed of? Enzymes are
catalysts for a reaction- explain what this means and explain why enzymes are
not considered a reactant.
Enzymes are made of proteins.
Enzymes speed up a chemical reaction by lowering the
activation energy for the reaction. They are not changed by
the chemical reaction and can catalyze the same reaction
over and over again.
40.
Define substrate and active site. Describe the lock and key model for
enzymes and relate this to enzyme specificity.
Substrates are the molecules that an enzyme acts upon (the
reactant in an enzyme catalyzed reaction.)
The active site is the space on the enzyme that the substrate
fits into.
Because the enzyme and substrate fit together like a lock and
key, each enzyme is (generally) specific for a particular
chemical reaction
41. Draw a graph showing the affect that temperature has on the rate of an
enzyme. Explain why it has this shape (explain all increases or decreases on
the graph).
Initially the temperature increase causes an increase in the reaction
rate, since the molecules are moving faster so the substrate will
come into contact with the active site of the enzyme more quickly.
However, at very high temperatures, the enzyme can denaturewhich means to unfold (because the high energy breaks apart the
hydrogen bonds that hold the enzyme together in the correct
shape.) If the enzyme is denatured, it does not have the correct
shape it cannot catalyze the reaction.
42. In hot climates, where organisms have to radiate excess heat from their
surface, is it an advantage to be larger or smaller. (Hint: Under these
conditions, organisms need a higher surface area to volume ratio to be able to
adequately radiate excess heat.)
A smaller size would provide a greater surface area to volume ratio
so it would be better able to radiate heat.
The ratio would be higher for a smaller size because as size
increases, the surface area increases only by the square compared
to the volume (in the denominator of the ratio) increases by the
cube. A larger object has less surface area PER unit of volume
(more total surface area but less per unit of volume).
Match the following cell parts with their function.
43.
44.
45.
46.
47.
48.
Nucleus __C____
Mitochondria __F____
Chloroplasts ___B___
Cell membrane ___E___
Ribosome__A___
Cell wall __D____
A.
B.
C.
D.
E.
F.
site of protein synthesis
site of photosynthesis
contains the DNA
provides structural support in plants
controls what enters & exits the cell
site of cell. respiration/ produces ATP
49. Explain the difference between prokaryotic and eukaryotic cells. What
types of organisms are composed of prokaryotic and eukaryotic cells?
Prokaryotic cells do not have any membrane-bound
organelles(no mitochondria, ER etc.). The DNA in a
prokaryote is not in a nucleus. Bacteria are composed on
prokaryotic cells.
Plants, animals, fungi and protest (unicellular eukaryotes) are
all eukaryotic.
50. Which statement is correct
A. Animal cells have a cell wall
B. Plant cells have a cell membrane (and a cell wall)
C. Animal cells don not have mitochondria
D. Plant cells do not have mitochondria
51. Which type of organism can break apart atmospheric nitrogen (N2) to
make other nitrogen compounds which can then be used by other living
things?
A. Certain plants
B. Certain bacteria
C. Certain fungi
D. A and B
E. B and C
While all living things need nitrogen atoms to build DNA and
proteins, most living things cannot utilize the abundant N2 in
the atmosphere. Only certain bacteria (called nitrogen-fixing
bacteria) can perform this task. Some plants, including beans
and other legumes, have root nodules to host these bacteria
in a symbiotic relationship. But it is the bacteria that
performs the job of nitrogen-fixing.