Download 2006, Biology

A caterpillar eats an oak leaf. Which of the following best describes the energy transfer in this situation?
A. Both the caterpillar and the leaf gain energy.
B. Energy is transferred from the leaf to the caterpillar.
C. Decomposers in the leaf obtain energy from the caterpillar.
D. The oak tree gains energy when the caterpillar eats the leaf.
The molecule ATP is composed of elements commonly found in organic molecules. Which of the following is one of
these elements?
A. aluminum
B. calcium
C. phosphorus
D. tin
The diagram below shows a strand of DNA matched to a strand of messenger RNA.
What process does this diagram represent?
A. mutation
B. respiration
C. transcription
D. translation
There are two types of modern whales: toothed whales and baleen whales. Baleen whales filter plankton from the water
using baleen, plates made of fibrous proteins that grow from the roof of their mouths. The embryos of baleen whales
have teeth in their upper jaws. As the embryos develop, the teeth are replaced with baleen.
Which of the following conclusions is best supported by this information?
A. Primitive whales had teeth as adults.
B. Toothed whales descended from baleen whales.
C. Baleen whales are evolving into toothed whales.
D. Descendants of modern baleen whales will have both teeth and baleen
as adults.
Which of the following explains why elements, such as carbon and oxygen, that are used in organic molecules are not
permanently removed from the environment?
A. They are replenished by sunlight.
B. They are cycled through ecosystems.
C. They are replaced by volcanic eruptions.
D. They are produced constantly from nutrients.
The diagram below represents a cell. The letters in the diagram represent alleles for two different genetic traits.
According to Mendel’s law of independent assortment, which of the following shows all of the allele combinations
expected in gametes produced by this cell?
A.
B.
C.
D.
Some cells, such as human nerve and muscle cells, contain many more mitochondria than do other cells, such as skin
cells. Why do some cells have more mitochondria than others?
A. The cells use more energy.
B. The cells store more nutrients.
C. The cells degrade more proteins.
D. The cells divide more frequently.
During the fall reproductive season, the belly of a male brook trout becomes bright orange. The orange belly provides
some camouflage and helps attract females.
This trait evolved in brook trout because, compared to males with pale bellies, males with bright orange bellies are more
likely to
A. live in good habitats.
B. be eaten by predators.
C. mate with other species of fish.
D. fertilize eggs to produce offspring.
Which of the following would most likely happen if grasses and shrubs were removed from a rural Massachusetts
ecosystem?
A. There would be an increase in consumers in the ecosystem.
B. There would be an increase of photosynthesis in the ecosystem.
C. There would be a decrease in food energy produced by the ecosystem.
D. There would be a decrease of carbon dioxide available to the ecosystem.
The illustration below shows a Siamese cat.
In Siamese cats, an enzyme determines the color of the fur. On the cooler places of the body, the enzyme causes darker
fur. On the warmer parts of the body, the enzyme does not function.
Which of the following statements best explains how temperature affects this enzyme?
A. Cooler temperatures denature the enzyme.
B. Cooler temperatures cause more enzyme production.
C. The enzyme is active in a specific temperature range.
D. Heat allows the enzyme to break down white pigment.
A biology student doing research collects the following information about feeding relationships in an Antarctic
ecosystem.
a. Use these notes to construct a food web of this ecosystem in your Student Answer Booklet.
b. In your food web, identify one organism at each of the following trophic levels: producer, primary consumer,
secondary consumer, and higher-order consumer.
The graph below shows the amount of ATP produced in a cell during a period of time.
According to the graph, which of the following processes must have increased between points A and B?
A. cellular respiration
B. cytokinesis
C. DNA replication
D. meiosis
In one of the steps of the carbon cycle, a person exhales a molecule of carbon dioxide (CO2) into the atmosphere.
Which of the following is most likely to happen next to the atom of carbon in this molecule?
A. It may be used as part of a sugar in a plant.
B. It may become part of a protein in an animal.
C. It may be consumed as a fossil fuel is burned.
D. It may be decomposed into carbon and oxygen by a bacterium.
Which of the following is more likely to occur in a plant cell than in an animal cell?
A. synthesis of enzymes
B. formation of cellulose
C. breakdown of glucose
D. active transport of ions
Which of the organisms shown below is not correctly labeled with its kingdom?
A.
B.
C.
D.
Which of the following correctly explains how atmospheric nitrogen is converted to nitrogen compounds used by living
organisms?
A. Sunlight converts atmospheric nitrogen to a form usable by protists.
B. Plant leaves convert atmospheric nitrogen to a form usable by animals.
C. Bacteria in soil convert atmospheric nitrogen to a form usable by plants.
D. Invertebrate animals in soil convert atmospheric nitrogen to a form usable by fungi.
Why is the particular sequence of bases in a segment of DNA important to cells?
A. Some base sequences code for protein production.
B. Some base sequences cause the release of lipids from the nucleus.
C. Some base sequences contain the order of sugars in polysaccharides.
D. Some base sequences produce electrical signals sent to the cytoplasm.
A single prokaryotic cell can divide several times in an hour. Few eukaryotic cells can divide as quickly. Which of the
following statements best explains this difference?
A. Eukaryotic cells are smaller than prokaryotic cells.
B. Eukaryotic cells have less DNA than prokaryotic cells.
C. Eukaryotic cells have more cell walls than prokaryotic cells.
D. Eukaryotic cells are more structurally complex than prokaryotic cells.
A food web is shown below.
In this food web, the trophic level with the least energy includes which of the following organisms?
A. grasses
B. mice
C. snakes
D. hawks
The diagram below illustrates how plant root cells take in mineral ions from the surrounding soil.
Which of the following processes is illustrated?
A. active transport
B. diffusion
C. osmosis
D. passive filtration
Within an individual mouse, four different mutations occurred in different genes, located on separate chromosomes and
in different cells, as shown in the table below.
Cell Type
Chromosome
Trait
Normal
Phenotype
Mutated
Phenotype
skin
chromosome 4
fur color
black fur
white fur
gamete
chromosome 3
eye color
brown eyes
blue eyes
muscle
chromosome 2
fur thickness
thick fur
thin fur
nerve
chromosome 1
tail length
long tail
short tail
Which of these mutations could be passed on to the mouse's offspring?
A. white fur
B. blue eyes
C. thin fur
D. short tail
Which of the following is a central role of carbon in the chemistry of living organisms?
A. Carbon can only bond with other carbon atoms.
B. Carbon is a solvent that breaks chemical bonds.
C. Carbon readily forms ionic bonds that separate easily.
D. Carbon can form many types of molecules with covalent bonds.
Which of the following occurs during photosynthesis?
A. CO2 is used to produce water.
B. CO2 is absorbed by mitochondria.
C. CO2 and H2O are converted to carbohydrates.
D. CO2 and H2O are combined into carbonic acid.
A food web in a rain forest is shown below.
Which of the following most likely occupies the location marked X in this food web?
A. decomposers
B. primary consumers
C. producers
D. secondary consumers
The maps below show South America and Africa. Areas where fossils of the same extinct plant species have been found
are marked with a star.
a. Explain how the widely separated areas marked in Map 2 can have fossils of the same extinct plant species.
In both South America and Africa, there are plants descended from this extinct species. These modern plants are very
different from one another.
b. Explain how the extinct species has modern descendants that came to be very different from one another.
In watermelons, solid dark green color (G) is dominant to stripes (g). A student crosses two watermelon plants that are
heterozygous for melon color (Gg).
a. In your Student Answer Booklet, make a Punnett square to show this cross. What are the expected percentages
of phenotypes of the offspring?
b. The student’s cross produces one hundred watermelon plants. Of those 100 plants, 78 plants produce solid dark
green watermelons, and 22 produce striped watermelons. Explain these results based on the Punnett square and
predictions you made in part (a).
The diagram below represents a fat molecule.
A fat molecule belongs to which category of organic molecules?
A. proteins
B. lipids
C. nucleic acids
D. carbohydrates
Human tears contain the enzyme lysozyme, which damages the cell walls of bacteria. Which of the following statements
about lysozyme is most accurate?
A. Lysozyme causes mutations in bacterial cell wall molecules.
B. Lysozyme is destroyed as it digests bacterial cell wall molecules.
C. Lysozyme breaks a specific type of bond in a bacterial cell wall molecule.
D. Lysozyme is converted to another chemical by a bacterial cell wall molecule.
Fertilizers can enable farmers to grow the same crop in a field for several years in a row. Farmers who use less fertilizer
often rotate their crops by planting the crop one year and legumes, such as beans and clover, the following year.
Fertilizer use and crop rotation with legumes both increase the availability of which of the following nutrients in soil?
A. calcium
B. nitrogen
C. oxygen
D. protein
A rare genetic condition causes dwarfism and immunodeficiencies. Which of the following is the most likely cause of
this condition?
A. a parasitic infection
B. a mutation in DNA
C. a bacterial disease
D. an excess of ATP
All organisms classified in kingdom Animalia must also be classified as which of the following?
A. Archaea
B. Eubacteria
C. Eukaryota
D. Protista
In the nucleus of a human cell, RNA polymerase travels along a DNA strand and constructs a new strand of mRNA. The
new mRNA strand leaves the nucleus through a pore in the nuclear membrane and enters the cytoplasm. The mRNA
associates with a ribosome and a new polypeptide is produced.
Several types of organic molecules are mentioned in the paragraph above.
a. Select two different organic molecules mentioned in the paragraph above and classify each as one of the four
major types of organic molecules. You may use a table like the one below in your response.
b. Briefly describe the structure and function of each organic molecule you identified in part (a). You may use a
table like the one below in your response.
Cheetahs have come close to extinction due to hunting, drought, and disease. There is now very little genetic variation
in cheetah populations.
Which of the following is a result of the limited genetic variation in the current cheetah populations compared to earlier
cheetah populations with more variation?
A. Cheetahs in current populations are more resistant to new diseases.
B. The survival rate of young cheetahs is increased in current populations.
C. Cheetahs in current populations are less able to interbreed with other species.
D. The current cheetah populations are less likely to be able to adapt to environmental changes.
Which of the diagrams below best represents the net movement of molecules in osmosis?
A.
B.
C.
D.
Which of the following genetic conditions results from a problem with segregation?
A. Trisomy 16: a condition caused when a zygote receives three copies of chromosome 16
B. Huntington’s disease: a condition caused when a zygote receives a mutated dominant allele
C. Hemophilia: a condition caused when a zygote receives an X chromosome with a particular recessive
allele
D. Sickle cell anemia: a condition caused when a zygote receives a recessive allele for hemoglobin from
each parent
Two spotted leopards produce a litter of four cubs. Three of the cubs are spotted and one is solid black. The black coat is
probably what type of trait?
A. dominant
B. recessive
C. polygenic
D. sex-linked
A freshwater food web is shown below.
The X in this food web most likely represents which of the following?
A. dragonfly larvae
B. Elodea plants
C. frog eggs
D. Paramecium species
Which of the following distinguishes the organisms in the kingdom Fungi from other eukaryotic organisms?
A. Fungi are unicellular.
B. Fungi reproduce sexually.
C. Fungi obtain nutrients by absorption.
D. Fungi make food through photosynthesis.
The diagrams below illustrate two different types of cell division.
Process A
Process B
a. Identify which diagram shows the process of mitosis and which diagram shows the process of meiosis.
b. Explain three differences between mitosis and meiosis. Your answer should include differences found in the
actual processes and differences found in the cells resulting from each type of division.
A partial food web for a marsh ecosystem is shown below.
The removal of which of the following organisms would most reduce the transfer of energy from aquatic organisms to
terrestrial organisms?
A. herring gulls
B. sandpipers
C. rats
D. ghost crabs
The illustration below represents a marine iguana.
The marine iguanas of the Galápagos Islands feed on seaweed and algae. Marine iguanas have flattened tails while other
species of iguanas that live inland on the Galápagos and on the South American mainland have rounded tails.
Which of the following best explains this difference in tail shape?
A. Flattened tails are better for swimming than rounded tails.
B. Flattened tails move more easily on land than in the ocean.
C. Flattened tails are harder for predators to grasp than rounded tails.
D. Flattened tails release heat more rapidly in the ocean than on land.
In which of the following ways are photosynthesis and cellular respiration alike?
A. Both processes produce glucose.
B. Both processes consume carbon dioxide.
C. Both processes take place in chloroplasts.
D. Both processes involve energy transformations.
A partial diagram of a reproductive process is shown below.
Which of the following labels belongs in the oval marked X?
A. egg
B. fetus
C. sperm
D. zygote
A cross section of part of a Golgi complex is shown below.
Part of the membrane of the Golgi complex pinches off and moves away. Which of the following is a function of this
process?
A. to release energy from ATP
B. to deliver proteins to other locations in the cell
C. to collect amino acids for use in protein synthesis
D. to send messages about cell requirements to the nucleus
A student researching bears found the chart below in a textbook. The chart shows the classifications of several types of
bears.
Which of the following conclusions is best supported by the data given in this chart?
A. Modern bears evolved from species that are now extinct.
B. The short-faced bear was the ancestor of the Asiatic black bear.
C. Present day bear species are more closely related than their ancestors were.
D. Natural selection favored the brown bear over the American black bear.
The diagram below shows a generalized cycle in sexually reproducing animals.
What is Process A in this cycle?
A. fertilization
B. mitosis
C. osmosis
D. replication
In comparisons of the evolutionary relationships between four species of birds, which of the following would be most
useful?
A. color of feathers
B. gene sequences
C. nesting behaviors
D. patterns of migration
Genetic information for a breed of chicken is shown below.
Frizzle Fowl
Types of Chickens with Different Feathers
Genotype
Phenotype
FF
Normal (Normal feathers)
Ff
Frizzle fowl (Curly feathers)
ff
Feather shedder (Loses feathers easily)
Which of the following crosses of chickens will produce only Frizzle fowl offspring?
A. Normal × Frizzle fowl
B. Frizzle fowl × Frizzle fowl
C. Normal × Feather shedder
D. Feather shedder × Feather shedder
Plants use many gallons of water every day. Almost all of the water used by plants is absorbed through the roots. Water
leaves plants by which process?
A. infiltration
B. precipitation
C. runoff
D. transpiration
The table below shows the elemental composition of three different types of organisms.
Elemental Composition of Selected
Organisms (percent by weight)
Element
Human
Alfalfa
E. coli
Bacterium
65.0
18.5
9.5
3.3
1.0
0.3
77.9
11.3
8.7
0.8
0.7
0.1
73.7
12.1
9.9
3.0
0.6
0.3
97.6%
99.5%
99.6%
O
C
H
X
P
S
Total
The X in the table represents which of the following elements?
A. calcium (Ca)
B. iron (Fe)
C. nitrogen (N)
D. sodium (Na)
The diverse organisms shown in the diagram below belong to the same Kingdom.
To which Kingdom do these organisms belong?
A. Animalia
B. Fungi
C. Plantae
D. Protista
Along the Pacific coast of North America, there are at least seven subspecies of Ensatina eschscholtzii salamanders. All
of them descended from a common ancestral population. As the species spread, subpopulations adapted to their local
environments.
Which of the following must have increased as a result of these adaptations?
A. the number of chromosomes in each salamander
B. the size of each salamander in the total population
C. the biodiversity of the total salamander population
D. the number of offspring produced by each salamander
The box below shows a list of supplies that are available in a laboratory.







four flasks with stoppers
floodlight
tap water
graduated cylinders
small aquarium plants
four small fish
bromthymol blue (a chemical indicator that changes color from blue to yellow as the level of carbon dioxide in
a solution increases)
The class sets up an experiment with the four flasks as shown.
Flask 1: 100 mL water, 1 mL bromthymol blue, plant
Flask 2: 100 mL water, 1 mL bromthymol blue, 2 small fish
Flask 3: 100 mL water, 1 mL bromthymol blue, 2 small fish, plant
Flask 4: 100 mL water, 1 mL bromthymol blue
Flask 1
Flask 2
Flask 3
Flask 4
All four flasks are stoppered and placed under the floodlight.
a. What color would the solution in each flask be after a few hours?
b. Explain how the processes that have occurred in each flask result in the observed color of the bromthymol blue
solutions.
DNA and RNA are similar because they both contain
A. deoxyribose.
B. nucleotides.
C. thymine.
D. double helices.
Four students attempted to classify organisms into the Plant and Animal Kingdoms. Their classifications are shown in
the table below.
Plants
Animals
Student 1
Eukaryotic
cells
Prokaryotic
cells
Student 2
Multicellular
Unicellular
Student 3
Cells have
cell walls
Cells do not
have cell walls
Student 4
Heterotrophic
by absorption
Heterotrophic
by ingestion
Which student’s classification correctly separates organisms into these two Kingdoms?
A. Student 1
B. Student 2
C. Student 3
D. Student 4
The diagram below shows a food web.
Which population would probably increase if the tadpole population decreased?
A. herons
B. alligators
C. fish
D. algae
Many animals have internal or external skeletons that provide support and structure. Which of the following parts of
plant cells play a similar role?
A. cell membranes
B. cell walls
C. chloroplasts
D. cytoplasm
The picture below shows two dogs and their puppies.
The parent dogs are each heterozygous for two traits: fur color and white spotting. Both parent dogs are solid black.
Their puppies, however, have four different phenotypes as listed below.




solid black
black with white spots
solid red
red with white spots
Which of the following explains how these parent dogs can produce puppies with these four phenotypes?
A. The genes for these traits are sex-linked.
B. The genes for these traits mutate frequently.
C. The genes for these traits assort independently.
D. The genes for these traits are on the same chromosome.
A food web is shown below.
Which organism in this food web is a decomposer?
A. American plum
B. golden mycena
C. metallic wood borer
D. white-tailed deer
The figure below represents the flow of food energy through a system.
In an experiment, chickens were fed grain that contained a chemical marker in its proteins. The presence of the marker
can be detected in organisms.
Which of the following is the most reasonable prediction from this experiment?
A. The marker will only be found in the grain.
B. Both chickens and wolves will have the marker.
C. Wolves will have the marker, but chickens will not.
D. The marker will only be found in the animals' wastes.
Cyanide is a powerful poison because it inhibits an enzyme in mitochondria, preventing the transfer of energy during
one of the steps in cellular respiration. This poison would directly affect the production of which of the following
molecules?
A. ATP
B. glucose
C. oxygen
D. RNA
The structure of an organic molecule is represented below.
In this organic molecule, which element is identified by each X?
A. iron
B. carbon
C. sodium
D. phosphorus
The diagrams below show changes in a desert lizard population.
1. Population with variety of inherited traits
2. Predation of individuals with particular
traits
3. Reproduction of survivors
Which biological concept is illustrated?
A. polygenic traits
B. natural selection
C. sex-linked inheritance
D. silent mutations
Which of the following is an example of a prokaryotic organism?
A. bacterium
B. celery
C. horse
D. mushroom
The natural cycling of oxygen between organisms and their environment is most directly accomplished through which
of the following pairs of processes?
A. fermentation and oxidation
B. transpiration and evaporation
C. precipitation and condensation
D. photosynthesis and respiration
The reaction catalyzed by the bacterial enzyme β-galactosidase forms a dark-colored end-product when the cells are
grown on a particular agar medium. As more product is formed, the cells become darker.
Students performed an experiment to determine the optimum pH for activity of this enzyme. Their results are shown in
the illustration of bacterial colonies below.
Bacterial Colony Color as a Function of pH
Based on these data, the students should conclude that β-galactosidase functions best at which pH?
A. 5
B. 7
C. 9
D. 11
A biology student observed the cells shown below under a microscope.
These cells most likely came from
A. an animal.
B. an archaebacterium.
C. a fungus.
D. a plant.
Which of the following is a primary function of carbohydrates?
A. storage of energy
B. transmission of genetic material
C. acceleration of chemical reactions
D. transport of molecules across membranes
Genetic information usually flows in one specific direction. Which of the following best represents this flow?
A. DNA → Protein → RNA
B. Protein → RNA → DNA
C. RNA → Protein → DNA
D. DNA → RNA → Protein
Legumes, such as clover and alfalfa, have nodules on their roots that contain nitrogen-fixing bacteria. These bacteria
convert nitrogen gas from the atmosphere into nitrates.
Which of the following best accounts for the presence of nitrogen-fixing bacteria in legume root nodules?
A. Nitrates are a food source for earthworms.
B. Plants can use nitrates, but not nitrogen gas.
C. Nitrates are one of the reactants in photosynthesis.
D. Nitrogen gas is toxic to most plants, but nitrates are nontoxic.
The following statements all apply to one element:

used by plants in photosynthesis

found in carbohydrates, proteins, and lipids

recycled by decay and burning

required element in all organic molecules
What is this element?
A. carbon
B. nitrogen
C. phosphorus
D. sulfur
Which of the following is an example of codominance in genetic traits?
A. A tall pea plant and a short pea plant produce tall pea plants.
B. An orange cat and a black cat produce an orange-and-black kitten.
C. A blue-eyed man and a brown-eyed woman produce a blue-eyed child.
D. A color-blind woman and a man with normal vision produce a color-blind son.
The diagram below shows an energy pyramid.
Approximately how much energy is available to the secondary consumers in this energy pyramid?
A. 10 kcal/m2/year
B. 100 kcal/m2/year
C. 1,000 kcal/m2/year
D. 5,000 kcal/m2/year
The wrasse and the blenny are two small fishes that resemble each other. The wrasse eats parasites attached to the skin
of other fish. Even some large predatory fish allow the wrasse to approach unharmed and eat parasites. Predatory fish
also allow the blenny to approach. However, instead of eating parasites, the blenny attacks the predatory fish.
a. Is there evolutionary pressure for the blenny to look like the wrasse? Explain what causes the presence or
absence of this evolutionary pressure. Be sure to use specific details in your answer.
b. Is there evolutionary pressure for the wrasse to look like the blenny? Explain what causes the presence or
absence of this evolutionary pressure. Be sure to use specific details in your answer.
A cell has a defect that results in the loss of its ability to regulate the passage of water, food, and wastes into and out of
the cell. In which of the following cell structures is this defect most likely to be located?
A. ribosomes
B. chloroplasts
C. cell membrane
D. endoplasmic reticulum
The graph below represents data gathered during an experiment on cellular respiration.
Which of the following conclusions is best supported by data from this graph?
A. ATP production is independent of sugar availability.
B. The amount of cellular respiration is constant in muscle cells.
C. ATP is only produced when sugar concentrations are above 4 g/L.
D. The amount of cellular respiration increases as sugar concentration increases.
The diagram below shows a biochemical pathway.
In one species of plant, the flower petals are normally purple if both enzyme A and enzyme B are produced. If a
mutation occurred that stopped production of enzyme A, but not enzyme B, what color flower petals would be
produced?
A. red
B. blue
C. white
D. purple
The algal cell pictured below is a single-celled organism.
When the algal cell is cut in two as shown, the bottom part can grow into a complete cell, but the top part cannot. What
conclusion does this support?
A. The ribosomes are found in the top of the cell.
B. The nucleus is found in the bottom of the cell.
C. The top of the cell contains most of its chromosomes.
D. The bottom of the cell contains most of its cytoplasm.
More than 1.5 million species of animals have been described, yet all of them have DNA that is made of the same
building blocks. This is evidence that all animals have
A. a common ancestor.
B. identical fossils.
C. similar appearances.
D. the exact same DNA sequences.
The diagram below shows some of the feeding relationships in a desert food web.
Which of the following trophic levels is not shown in this diagram?
A. producers
B. decomposers
C. primary consumers
D. secondary consumers
The diagram below shows a sea star in various stages of regeneration.
What cellular process is directly responsible for this regeneration?
A. meiosis
B. mitosis
C. transpiration
D. respiration
An amoeba, an oak tree, a squirrel, and mildew are all classified in the same
A. domain.
B. kingdom.
C. genus.
D. species.
Many aquatic birds secrete waxy organic substances that repel water. The birds use these substances to coat their
feathers. An analysis of these substances would reveal that they are composed mostly of
A. lipids.
B. proteins.
C. carbohydrates.
D. nucleic acids.
A Punnett square is a tool used to predict the outcome of a genetic cross.
a. Make a Punnett square for the cross of a father heterozygous for short fingers and a mother homozygous
dominant for short fingers. Use B to indicate the allele for short fingers and b to indicate the allele for long
fingers.
b. Identify the expected percentages of the phenotypes in the F1 generation for the cross in part a.
c. Make a Punnett square for the cross of a tall father who is homozygous dominant for height and a short mother
who is homozygous recessive for height. Use T to indicate the allele for tall and t to indicate the allele for short.
d. Identify the expected percentages of the phenotypes in the F1 generation for the cross in part c.
The illustration below shows part of the carbon cycle.
At position Y, carbon is most likely to be in which of the following forms?
A. protein
B. carbon solid
C. carbohydrate
D. carbon dioxide
A mutation that prevents a maple tree from efficiently taking gases from the air would most directly affect which of the
following processes?
A. reproduction
B. photosynthesis
C. water uptake
D. DNA replication
Carbon atoms in organic molecules most commonly bond to atoms of hydrogen, oxygen, and
A. calcium.
B. magnesium.
C. nitrogen.
D. sodium.
A human zygote, like most other human cells, contains 46 chromosomes. How many chromosomes does a zygote
receive from the mother?
A. 0
B. 23
C. 46
D. 92
Ovalbumin is a protein found in eggs. Which of the following best describes the molecular structure of ovalbumin?
A. a group of six carbon atoms joined in a ring
B. a chain of amino acids folded and twisted into a molecule
C. a set of three fatty acids attached to a molecule of glycerol
D. a sequence of nitrogenous bases attached to a sugar-phosphate backbone
A tomato plant in a greenhouse was found to be infected with tobacco mosaic virus.
A few weeks later, nearby plants were also found to be infected with the virus.
Which of the following best describes how the virus reproduced?
A. The virus made its own spores.
B. The virus produced seeds in the tomatoes.
C. The virus used the host plant’s resources and machinery to reproduce.
D. The virus immediately killed the host plant and was free to reproduce.
The following section focuses on nutrition information for dairy milk and soymilk.
Read the information below and use it to answer the four multiple-choice questions and one
open-response question that follow.
Milk is an important part of many people’s diets. When the word milk is mentioned,
most people think
of dairy milk derived from cows. Many people, however, cannot drink dairy milk
because of lactose
intolerance. Individuals with this condition are unable to digest a component in the milk
called lactose.
Lactose is the sugar in dairy milk. It is a disaccharide made from the sugars glucose and
galactose.
Lactose-intolerant individuals lack the enzyme lactase, which is needed for the digestion
of lactose sugar.
Many lactose-intolerant individuals drink soymilk instead of dairy milk. Soymilk is
produced from
soybeans (the seeds of the soybean plant) and is a nutritious substitute for dairy milk.
Soymilk contains
protein, calcium, and other essential nutrients just as dairy milk does.
The table below compares some of the nutrition information for a serving of dairy milk
and a serving
of soymilk.
Dairy Milk and Soymilk Nutrition Information
Reading section is above
When lactose is digested by the human body, each lactose molecule is broken down into
smaller molecules. To which of the following categories of molecules do these smaller
molecules belong?
A. amino acids
B. monosaccharides
C. nucleic acids
D. polypeptides
Reading section is above
Which type of milk, per serving, will theoretically yield a greater amount of ATP in the human body, and what is the
reason for this?
A. dairy milk, because it contains vitamin C
B. soymilk, because it contains no cholesterol
C. dairy milk, because it has larger amounts of sugar and fat
D. soymilk, because it has larger amounts of vitamins A and D
Reading section is above
Individuals with one form of lactose intolerance do not produce the enzyme lactase because the gene coding for the
production of lactase is shut off in their cells. This means that which of the following processes does not occur for the
gene?
A. hydrogenation
B. mutation
C. replication
D. transcription
Reading section is above
Unlike dairy milk, soymilk provides some of the body’s daily requirement for iron. In which of the following functions
of the human body does iron serve a primary role?
A. conducting nerve impulses
B. strengthening bone structure
C. causing muscle fibers to contract
D. helping transport oxygen in the blood
The digestion of dairy milk or soymilk provides the body with important nutrients.
a. Describe how the digestive system converts the carbohydrates, proteins, and fats in dairy milk or soymilk into
nutrients that can be used by cells. Include the body parts and organs involved.
b. Describe how the nutrients in the digestive system are made available to cells throughout the body after
digestion has occurred. Include the body parts and organs involved.
A diagram of an organic molecule is below.
Which element is found at the positions marked by the dots (•) in the molecule?
A. carbon
B. nitrogen
C. phosphorus
D. sulfur
Students in a biology laboratory are monitoring the rate at which hydrogen peroxide breaks down to produce water and
oxygen gas. They begin monitoring a sample of hydrogen peroxide and then add catalase, an enzyme that speeds up its
breakdown. Their data are shown in the table below.
Time
(min)
Rate of Hydrogen
Peroxide Breakdown
(molecules per min)
0.0
0.000
0.5
0.030
1.0
0.032
1.5
4,970,000.000
2.0
5,001,000.000
2.5
4,985,300.000
3.0
5,021,700.000
Based on the data in this table, during which of the following
students add the catalase to the hydrogen peroxide?
A. between 0.0 and 0.5 min
time periods did the
B. between 1.0 and 1.5 min
C. between 2.0 and 2.5 min
D. between 2.5 and 3.0 min
When gametes are produced from a parent cell during normal meiosis, which of the following describes the number of
chromosomes in each resulting cell?
A. Each resulting cell has the same number of chromosomes as the parent cell.
B. Each resulting cell has twice the number of chromosomes as the parent cell.
C. Each resulting cell has one-half the number of chromosomes as the parent cell.
D. Each resulting cell has one-fourth the number of chromosomes as the parent cell.
Which of the following most likely happens in the cells of a person running in the Boston Marathon?
A. The respiration rate increases to
produce more ATP.
B. The replication rate increases to
produce more DNA.
C. The photosynthesis rate increases
to produce more sugars.
D. The cell division rate increases to
produce more muscle fibers.
Which of the following organisms is eukaryotic, multicellular, and autotrophic?
A.
B.
C.
D.
Some bacteria live in hot springs. Their cells contain enzymes that function best at temperatures of 70°C or higher.
At a temperature of 50°C, how will the enzymes in these bacterial cells most likely be affected?
A. The enzymes will be destroyed
by lysosomes.
B. The enzymes will lose their
bond structure and fall apart.
C. The enzymes will require
less energy to function than
at 70°C.
D. The enzymes will not increase the
rate of reactions as much as they
would at 70°C.
The illustrations below represent two different cells.
Which of the following statements best identifies these two cells?
A. Cell X is a prokaryotic cell and cell Y is a eukaryotic cell.
B. Cell X is an archae cell and cell Y is a eubacterial cell.
C. Cell X is a red blood cell and cell Y is a muscle cell.
D. Cell X is a plant cell and cell Y is an animal cell.
The diagram below shows a cross section of part of a cell membrane.
a. Describe the basic structure of the cell membrane.
b. Describe two primary functions of the cell membrane.
c. Explain how the structure of the cell membrane allows it to perform the functions
described in part (b).
If scientists search other planets for possible life, they are likely to focus on the presence of molecules containing which of
the following elements?
A. carbon
B. iron
C. potassium
D. sodium
Many land plants store energy in starch. When energy is needed, the starch molecules can be broken down quickly.
This chemical reaction produces which of the following?
A. amino acids
B. lipids
C. monosaccharides
D. RNA chains
Which of the following best describes the formation of a zygote?
A. A sperm cell nucleus and an egg cell
nucleus fuse.
B. A cell's DNA replication and mitosis
are accelerated.
C. A succession of cell divisions produces
a solid mass of cells.
D. A cell with 46 chromosomes divides to
form cells with 23 chromosomes each.
Which of the following functions does active transport perform in a cell?
A. packaging proteins for export from
the cell
B. distributing enzymes throughout the
cytoplasm
C. moving substances against a
concentration gradient
D. equalizing the concentration of water
inside and outside the cell
Which of the following is a main function of the cell wall?
A. to store carbohydrates for later use
B. to give the cell a rigid structure
C. to package proteins for export
D. to carry out photosynthesis
The following section focuses on the interactions of organisms in a food web.
Read the information below and use it to answer the four multiple-choice questions and one openresponse question that follow.
A partial food web for organisms in Yellowstone National Park is shown below.
Which process do the animals in the food web use to convert energy from food into ATP?
A. cellular respiration
B. osmosis
C. photosynthesis
D. transcription
Reading section in above question.
Which organism in the food web is classified into kingdom Fungi?
A. Idaho fescue
B. king bolete
C. migratory grasshopper
D. yellow-bellied marmot
Which of the following organisms is a secondary consumer in this food web?
A. yellow-bellied marmot
B. strawberry plant
C. least chipmunk
D. king bolete
Which of the following releases oxygen into this food web ecosystem?
A. elk respiration
B. Idaho fescue photosynthesis
C. sweet cicely root decomposition
D. migratory grasshopper reproduction
Assume the elk population in Yellowstone National Park increases. Discuss how this increase in elk will most likely
affect each of the following populations:



Idaho fescue
migratory grasshopper
grizzly bear
Be sure to include specific reasons to support each of your responses.
Which of the following statements correctly matches a cell part with its function?
A. The cell membrane packages lipids
for export.
B. The mitochondria perform
photosynthesis.
C. The lysosome digests molecules.
D. The nucleus produces energy.
The drawing below represents an organism that a student observed when examining a sample of pond water with a light
microscope.
The student identified this organism as a prokaryote.
a. Is the student's identification accurate? Explain your answer using information from the diagram.
b. Identify three similarities between the cells of prokaryotes and eukaryotes.
In red blood cells, the compound carbonic anhydrase increases the rate at which carbon dioxide is converted
to bicarbonate ions for transport in the blood. In red blood cells, carbonic anhydrase acts as which of the following?
A. an enzyme
B. a hormone
C. a lipid
D. a sugar
Many plants have waxy coatings on some surfaces. This coating reduces water loss
because it is not water-permeable. This waxy coating is which of the following types of organic molecule?
A. carbohydrate
B. lipid
C. nucleic acid
D. protein
The diagram below provides information about a carrot cell.
A carrot cell contains 18 chromosomes. Which of the following diagrams illustrates the correct number of
chromosomes in new cells produced by mitosis?
A.
B.
C.
D.
In a certain variety of chicken, some offspring have a feather pattern that is black-and-white checkered. Chickens with this
checkered feather pattern result from the cross of a black chicken with a white chicken.
Which of the following types of inheritance is most likely responsible for the checkered feather pattern?
A. codominant
B. dominant
C. polygenic
D. sex-linked
The diagram below shows the final steps of a biochemical pathway used by the bacterium Serratia marcescens to produce
a red pigment molecule. Letters X, Y, and Z represent intermediate molecules produced in the pathway. Four enzymes are
also involved in the pathway, as shown.
A mutant strain of S. marcescens produces molecules X and Y but does not produce the red pigment molecule or molecule
Z.
Based on this result, it can be concluded that there must be a mutation in the gene coding for which enzyme?
A. enzyme 1
B. enzyme 2
C. enzyme 3
D. enzyme 4
Which of the following statements best describes a DNA molecule?
A. It is a double helix.
B. It contains the sugar ribose.
C. It is composed of amino acids.
D. It contains the nitrogenous base uracil.
In fruit flies, a single gene controls wing phenotype. The diagram below shows the phenotypes for long wings and
vestigial wings in fruit flies.
Two fruit flies that have long wings are crossed. Of the 95 offspring produced, 73 have long wings. The other 22 have
vestigial wings.
Which of the following conclusions about the inheritance of long wings and vestigial wings is best supported by the
results of this experiment?
A. The alleles for long wings and vestigial wings are sex-linked.
B. The alleles for long wings and vestigial wings are codominant.
C. The allele for long wings is dominant and the allele for vestigial wings is recessive.
D. The allele for long wings is recessive and the allele for vestigial wings is dominant.
Corn snakes show variety in their skin color pattern. While the complete genetics of corn snake color are complex,
the most common colors on normal corn snakes—red and black— are each coded by one gene.
For the red gene, the allele for the presence of red pigment (R) is dominant and the allele for the absence of red
pigment (r) is recessive. Likewise, for the black gene, the allele for the presence of black pigment (B) is dominant
and the allele for the absence of black pigment (b) is recessive.
a. Draw the Punnett square for the cross of a snake that is homozygous dominant for the red color with a snake that
is heterozygous for the red color. What percentage of the offspring is expected to have red pigment in their skin?
b. Draw the Punnett square for the cross of two snakes that are heterozygous for the black color. What percentage of
the offspring are expected to have black pigment in their skin?
c. The parent snakes in part (b) that are heterozygous for black color are both homozygous recessive for the red gene.
Each parent has genotype rr for the red gene. Based on this information, what percentage of their offspring are
expected to lack both the red and black pigments in their skin? Explain your reasoning.
In sheep, the allele for white wool (W) is dominant, and the allele for black wool (w) is recessive. A farmer has mated two
Suffolk sheep for a few years. These matings have resulted in six offspring, four with white wool and two with black
wool. One parent has white wool and the other has black wool.
Which of the following could be the genotypes of the parent sheep?
A. WW and Ww
B. WW and ww
C. Ww and Ww
D. Ww and ww
The diagram below represents part of a process that occurs in cells.
Which process is represented?
A. meiosis
B. osmosis
C. replication
D. translation
In pea plants, the genes for seed color and seed shape are on different chromosomes. Which of the following
explains why the genes for these traits are not inherited together?
A. natural selection
B. artificial selection
C. the law of segregation
D. the law of independent assortment
Which of the following best describes the result of a mutation in an organism's DNA?
A. The mutation may produce a zygote.
B. The mutation may cause phenotypic change.
C. The mutation causes damage when it occurs.
D. The mutation creates entirely new organisms.
The pedigree below shows the occurrence of Becker muscular dystrophy in a family. Becker muscular dystrophy causes
muscle weakness.
Based on this pedigree, it is most reasonable to conclude that Becker muscular dystrophy is which of the following?
A. a polygenic trait
B. a codominant trait
C. a sex-linked recessive trait
D. an autosomal dominant trait
The mold Aspergillus flavus grows on grain. A. flavus produces a toxin that binds to DNA in the bodies of animals that eat
the grain.
The binding of the toxin to DNA blocks transcription, so it directly interferes with the ability of an animal cell to do
which of the following?
A. transport glucose across the cell membrane into the cytoplasm
B. produce ATP using energy released from glucose and
other nutrients
C. transfer proteins from the endoplasmic reticulum to Golgi complexes
D. send protein-building instructions from the nucleus to the cytoplasm and ribosomes
Human blood types are genetically determined. The table below shows the symbols used to represent two of the alleles for
blood types and gives a description of each allele.
In homozygous individuals, two IA alleles result in blood type A and two IB alleles result in blood type B.
The IA and IB alleles are codominant, resulting in blood type AB in individuals heterozygous for the two alleles.
A male and a female both have blood type AB. If they have a child, what is the probability that the child will also have
blood type AB?
A.
B.
C.
D.
In 1950, Erwin Chargaff and colleagues examined the chemical composition of DNA and demonstrated that the amount of
adenine always equals that of thymine, and the amount of guanine always equals that of cytosine. This observation
became known as Chargaff's rule.
a. Based on current knowledge of the structure of DNA, explain the basis of Chargaff's rule.
b. The diagram below represents a single-stranded segment of DNA. In your Student Answer Booklet, write the
complementary DNA strand that would form from this strand during replication. Use the letters A, C, G, and T to
designate the bases: A = adenine; C = cytosine; G = guanine; T = thymine.
c. Why is Chargaff's rule so important to DNA's ability to replicate itself accurately?
In phenylketonuria (PKU), an enzyme that converts one amino acid into another does not work properly. Which of the
following is the most likely cause of this genetic condition?
A. an error in the transcription of the gene for the enzyme
B. a mutation in the DNA sequence that codes for the enzyme
C. an excess of the amino acids necessary to produce the enzyme
D. a structural variation in the amino acid modified by the enzyme
The diagram below shows the positions of the genes for flower color and stem length in a pea plant. The chromosomes
represented below will replicate before meiosis.
For these two genes, what is the maximum number of different allele combinations that can be formed normally in
gametes produced from this cell?
A. 2
B. 4
C. 6
D. 8
Which of the following terms applies to traits, such as human eye color, that are controlled by more than one gene?
A. codominant
B. polygenic
C. recessive
D. sex-linked
In pigeons, the allele B produces ash-red feathers. The allele b produces blue feathers. The B allele is dominant to the b
allele.
A pigeon with genotype Bb is crossed with a pigeon with genotype bb. What percent of the offspring are expected to have
ash-red feathers?
A. 0%
B. 25%
C. 50%
D. 100%
Which of the following provides the most conclusive evidence that organisms of two different species share a common
ancestor?
A. They live in the same ecosystem.
B. They reproduce at the same time.
C. They have similar DNA sequences.
D. They have similar body movements.
Blue jays and kingbirds are both classified in the order Passeriformes. In the current taxonomic system, this
means that the two types of birds must also belong to the same
A. family.
B. genus.
C. phylum.
D. species.
Dutch elm disease is a fungal infection of elm trees that usually results in death. The disease has killed millions of North
American elm trees that were not resistant to the fungus. Scientists have bred resistant elms by crossing North American
species with Asian species that show resistance.
Which of the following best describes how natural selection would promote resistant elm populations once the
resistance genes from the Asian species were successfully introduced?
A. After encountering elms with resistance genes, fungi would avoid elms and begin to attack
other tree species.
B. Resistance would spread to all of the mature elms in a population from the few trees that
acquired the resistance genes.
C. By reproducing with each other, elm trees with resistance genes would create super-resistant
elms with twice the number of resistance genes.
D. Elm trees with resistance genes would survive and pass on resistance to offspring, while trees
without resistance would more likely be killed by the fungus.
Which of the following best explains how the fossil record provides evidence that evolution has occurred?
A. It indicates that forms of life existed on Earth at least 3.5 billion years ago.
B. It indicates the exact cause of structural and behavioral adaptations of organisms.
C. It shows how the embryos of many different vertebrate species are very similar.
D. It shows that the form and structure of groups of organisms have changed over time.
On island chains like the one shown below, animal populations that spread from the main island to the other islands can
evolve into separate species.
Which of the following best explains what favors speciation in these situations?
A. Predators on the main island can easily migrate to follow the populations to the other islands.
B. Lack of disease on the other islands enables the populations to grow and change without limit.
C. The physical separation of the islands limits gene flow and interbreeding between the
populations.
D. The climatic conditions of the islands allow the populations to breed all year and produce several
generations.
Frogs, lizards, and birds all have a similar arrangement of bones in their limbs. Which of the following does this similarity
most likely indicate about these animals?
A. They move in the same way.
B. They have a common ancestry.
C. They evolved at the same time.
D. They are comparable in size as adults.
The outermost tail feather of the male barn swallow is longer than that of the female barn swallow. The long tail feather
helps the males attract females, but it also requires the males to use extra energy to fly.
The long tail feather trait is maintained in the barn swallow populations because, compared to males with a shorter tail
feather, males with a longer tail feather are more likely to
A. build a large nest.
B. produce offspring.
C. migrate each winter.
D. escape from predators.
On the Galápagos Islands, finches adapted over time to different food sources through changes in their beak structure.
Which of the following most likely resulted from the finches’ beak structure adaptations?
A. a decreased predation on finches
B. an increased species diversity of finches
C. an increased competition among finches
D. a decreased reproductive rate in finches
The graph below relates the number of gray squirrels in a small population to their coat colors.
This squirrel population has been separated from other squirrel populations by a new highway
and several construction sites. The main predators of these squirrels are cats and hawks.
a. Assume that dark gray squirrels are very visible in this new environment. What is likely to
happen to the distribution of coat color in this squirrel population over several generations?
Sketch a graph in your Student Answer Booklet to show the predicted distribution, and explain
your answer.
b. Assume that dark gray squirrels are very visible on the ground, and light gray squirrels are
very visible in the trees. Explain what is likely to happen to the distribution of coat color
in the squirrel population over several generations. You may sketch a graph in your Student
Answer Booklet as part of your explanation.
Starting in 1954, commercial fishers in the northwest Pacific were paid by weight, rather than by the individual
fish, for pink salmon. The fishers increased the use of a type of net that selectively catches larger fish.
Which of the following effects did this change in fishing techniques most likely have on the salmon population over the
next 20 years?
A. The average body size of the salmon population increased significantly.
B. The average body size of the salmon population decreased significantly.
C. The average body size of the males in the salmon population increased
and the average body size of females in the salmon population stayed the same.
D. The average body size of the males in the salmon population stayed the
same and the average body size of the females in the salmon population increased.
Caytonia is an extinct plant that existed between 200 and 140 million years ago. It had reproductive structures that
resemble structures in modern flowering plants.
How do scientists know about the structures of this ancient extinct plant?
A. Scientists study the DNA sequences of Caytonia.
B. Scientists genetically engineer modern plants to produce Caytonia.
C. Scientists excavate and examine the fossilized remains of Caytonia.
D. Scientists observe the adaptations of plants in habitats resembling those of Caytonia.
The illustrations below show a South American finch and some of the species of finches found on the Galápagos Islands.
The map shows the relationship of the Galápagos Islands to the west coast of South America.
There are 13 species of finches found on the Galápagos Islands. These finches have a wide variety of food sources and
beak shapes. There is one genetically similar species of finch found on the South American mainland. This finch eats
small seeds.
Use the map and the bird illustrations to identify and explain two ways that these finches provide evidence that supports
the theory of evolution.
European rabbits were introduced to Australia in 1859. The rabbits reproduced rapidly in their new habitat,
displaced other animals, and overgrazed vegetation. In an attempt to reduce the rabbit population, a virus was introduced
in 1951. This virus is usually deadly to European rabbits.
When the virus was first introduced, the rabbits died in large numbers, but the death rate decreased over time. Which of
the following best explains the decrease in the rabbit death rate?
A. Young rabbits learned to avoid being infected with this virus.
B. Natural selection favored rabbits that are resistant to this virus.
C. The lifespan of this virus is too short to affect rabbits over a long period of time.
D. The rabbits that were originally infected with this virus have been dead for many years.
In a mouse population inhabiting a grassland area, a mutation occurs that results in a new coat color allele.
Which of the following factors has the greatest effect on whether the new coat color will become more common in the
mouse population?
A. whether abundant food is available in the grassland
B. whether the new coat color allele is dominant or recessive
C. whether the rate of reproduction in the mouse population is stable
D. whether the new coat color allele increases the survival of mice in their environment
Similar structures are present in the
embryos of fish, chickens, and rabbits. In fish, these structures develop into gills, but in chickens and rabbits, they either
disappear or develop into other body parts later in embryonic development.
Which of the statements below best explains the presence of these structures in the embryos of all three species?
A. The embryos of the three species are similar in size.
B. Breathing structures are similar among the young of the three species.
C. The three species have a common ancestor with these embryonic structures.
D. The reproductive mechanisms are similar among the adults of the three species.
The illustrations below show vestigial pelvic bones of a baleen whale and vestigial hind limb bones of an extinct whale.
The presence of these bones in the baleen whale and extinct whale provides evidence of which of the following?
A. Whales can travel on land when necessary.
B. Whales evolved from four-legged animals.
C. Whales have functional legs that are hidden by fat and skin.
D. Whales are developing into animals with four functioning limbs.
Some willow trees alter the chemical composition of their leaves when attacked by caterpillars. Compared to normal
leaves, the chemically altered leaves are less nutritious and are more difficult for caterpillars to digest.
Which of the following is a likely effect of this ability to alter leaf composition?
A. Willow trees with this ability will attract more caterpillars than other willow trees.
B. Willow trees with this ability will have a survival advantage over other willow trees.
C. More butterflies will lay their eggs on willow trees with this ability than on
other willow trees.
D. Caterpillars that feed on willow trees with this ability will be larger than
caterpillars on other willow trees.
The drawings below show some trilobite and crinoid fossils.
Which of the following is the most reasonable conclusion when fossils of these two different types of organisms are found
in the same layers of rock?
A. Crinoids were prey for trilobites.
B. Crinoids were ancestors of trilobites.
C. Crinoids and trilobites had similar behaviors.
D. Crinoids and trilobites lived at the same time.
Which of the following organs removes extra water from the blood to keep the amount of fluid in the
bloodstream at the proper level?
A. kidneys
B. liver
C. pancreas
D. stomach
The diagram below shows the locations of the pituitary gland and the kidneys in the human body.
The pituitary gland can release a substance into the bloodstream that signals target cells in the kidneys to
reabsorb more water. The released substance is an example of
A. an enzyme.
B. a hormone.
C. a neurotransmitter.
D. a vitamin.
Which of the following is a correct order in which air moves through the human respiratory system when a person
inhales?
A. nose, larynx, trachea, pharynx, bronchi, lungs
B. nose, pharynx, larynx, trachea, bronchi, lungs
C. pharynx, bronchi, nose, larynx, trachea, lungs
D. pharynx, nose, trachea, bronchi, larynx, lungs
In sexual reproduction, what is the source of the genetic material in a zygote?
A. an egg cell only
B. a sperm cell only
C. an egg cell and a sperm cell
D. an egg cell and a polar body
What is the primary function of the large intestine?
A. to digest proteins
B. to absorb nutrients
C. to break down complex carbohydrates
D. to remove water from undigested waste
Capillaries are part of which body system?
A. skeletal system
B. nervous system
C. digestive system
D. circulatory system
Which of the following is one of the functions of the human skeleton?
A. producing hormones
B. bringing gases into the body
C. removing waste from the body
D. providing a cite for blood cell formation
When a person exercises, the rate of cellular respiration increases to supply the body with more energy in the form of
ATP. Mitochondria require oxygen to carry out cellular respiration.
Describe how the respiratory, circulatory, and muscular systems interact to transport a molecule of oxygen from the air to
a mitochondrion. Be sure to discuss all three systems in your response.
Which of the following is the best example of an organism maintaining homeostasis?
A. a wolf panting after a chase
B. a spider catching an insect in a web
C. a cricket becoming infected by a virus
D. a mole digging tunnels in the ground
Which of the following is the basic structural unit of the nervous system?
A. axon
B. neuron
C. red blood cell
D. white blood cell