USABO OPEN Final Exam Questions with 100%
Correct Answers Latest Versions 2025 Graded
A+
1. In superoxide dismutase 1, an enzyme implicated in amyotrophic lateral
sclerosis (Lou Gehrig's disease), a copper ion is bound to the active site and
is important for enzyme activity. In this enzyme, copper most likely functions
as a(n): cofactor
2. The order of normal blood flow through the human heart is: right atrium,
right ventricle, lungs, left atrium, left ventricle, body
3. Allopatric speciation refers to species formed after which type of separa-
tion:: geographic
4. Which two functional groups are always found in amino acids?: Carboxyl
and amine
5. Movement of ions across the membrane from higher to lower concentra-
tions through a channel protein is an example of: Facilitated diffusion
6. Which group of plants has vascular tissue but does not produce seeds?
I. Mosses
II. Ferns
III. Gymnosperms: II
7. Which of the following is true for transport in xylem?: Movement through
xylem depends mainly on transpiration
8. Predation is considered a interaction, while Mutualism is con-
sidered a interaction.: +/-, +/+
9. Which of the following organisms is INCORRECTLY paired with its trophic
,level?: Beetle - secondary consumer
10. Which of the following is an example of habituation?: Hydra initially contract
when gently touched, but soon stop responding.
11. Suppose gene "C" is the gene for color. Its dominant allele has the effect of
allowing the production of fur color while its recessive allele interrupts color
production. At another locus, there exists another gene that influences color,
at which black (B) is dominant to brown (b). What is the relationship between
these genes called?: Epistatic
12. During migrations, some birds use which of the following as reference
frameworks?
I. The sun
II. Constellations
III. Earth's magnetic field: I,II, and III
13. Generally, there are more species per square kilometer in which of the
following types of ecosystem?: Coral reef
, 14. RUBP is used and PGA is formed in:: dark reaction (Calvin cycle) of photo-
synthesis
15. Which is TRUE of the dark reaction (Calvin cycle) of photosynthesis?: It
uses carbon dioxide
16. In the fern life cycle, the dominant generation is the:: diploid sporophyte
17. Assume a person is placed on cortisol medication, a glucocorticoid. How
would you expect the rates of ACTH and CRF hormone production to change
in the person?: ACTH production would decrease, CRF production would increase
18. Carbon particles were injected into the blood of mice. In which of the
following places would you most likely find the particles?: In monocytes of the
spleen
19. Kidneys provide osmoregulation for the body. Consumption of which nu-
trient creates the greatest need for osmoregulation?: Protein
20. During translation in prokaryotes, the ribosome binds to:: the Shine-Dalgar-
no sequence
21. The quaternary structure of a protein is determined by:: .interactions be-
tween amino acids of different polypeptide chains.
22. Which of the following is not a function of the parasympathetic division of
the nervous system?: . Stimulation of the adrenal medulla
23. You place a growing seedling in an east-facing window. On which side of
the plant will active auxin accumulate?: West side
24. Which of the following is NOT a characteristic of all mammalian species?-
: Placenta
25. Suppose the lac repressor of E. coli is mutated so that it never binds to the
operator. Which of the following is true?: The result depends on the concentration
Correct Answers Latest Versions 2025 Graded
A+
1. In superoxide dismutase 1, an enzyme implicated in amyotrophic lateral
sclerosis (Lou Gehrig's disease), a copper ion is bound to the active site and
is important for enzyme activity. In this enzyme, copper most likely functions
as a(n): cofactor
2. The order of normal blood flow through the human heart is: right atrium,
right ventricle, lungs, left atrium, left ventricle, body
3. Allopatric speciation refers to species formed after which type of separa-
tion:: geographic
4. Which two functional groups are always found in amino acids?: Carboxyl
and amine
5. Movement of ions across the membrane from higher to lower concentra-
tions through a channel protein is an example of: Facilitated diffusion
6. Which group of plants has vascular tissue but does not produce seeds?
I. Mosses
II. Ferns
III. Gymnosperms: II
7. Which of the following is true for transport in xylem?: Movement through
xylem depends mainly on transpiration
8. Predation is considered a interaction, while Mutualism is con-
sidered a interaction.: +/-, +/+
9. Which of the following organisms is INCORRECTLY paired with its trophic
,level?: Beetle - secondary consumer
10. Which of the following is an example of habituation?: Hydra initially contract
when gently touched, but soon stop responding.
11. Suppose gene "C" is the gene for color. Its dominant allele has the effect of
allowing the production of fur color while its recessive allele interrupts color
production. At another locus, there exists another gene that influences color,
at which black (B) is dominant to brown (b). What is the relationship between
these genes called?: Epistatic
12. During migrations, some birds use which of the following as reference
frameworks?
I. The sun
II. Constellations
III. Earth's magnetic field: I,II, and III
13. Generally, there are more species per square kilometer in which of the
following types of ecosystem?: Coral reef
, 14. RUBP is used and PGA is formed in:: dark reaction (Calvin cycle) of photo-
synthesis
15. Which is TRUE of the dark reaction (Calvin cycle) of photosynthesis?: It
uses carbon dioxide
16. In the fern life cycle, the dominant generation is the:: diploid sporophyte
17. Assume a person is placed on cortisol medication, a glucocorticoid. How
would you expect the rates of ACTH and CRF hormone production to change
in the person?: ACTH production would decrease, CRF production would increase
18. Carbon particles were injected into the blood of mice. In which of the
following places would you most likely find the particles?: In monocytes of the
spleen
19. Kidneys provide osmoregulation for the body. Consumption of which nu-
trient creates the greatest need for osmoregulation?: Protein
20. During translation in prokaryotes, the ribosome binds to:: the Shine-Dalgar-
no sequence
21. The quaternary structure of a protein is determined by:: .interactions be-
tween amino acids of different polypeptide chains.
22. Which of the following is not a function of the parasympathetic division of
the nervous system?: . Stimulation of the adrenal medulla
23. You place a growing seedling in an east-facing window. On which side of
the plant will active auxin accumulate?: West side
24. Which of the following is NOT a characteristic of all mammalian species?-
: Placenta
25. Suppose the lac repressor of E. coli is mutated so that it never binds to the
operator. Which of the following is true?: The result depends on the concentration
