100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached 4.6 TrustPilot
logo-home
Exam (elaborations)

USABO Open Exam Questions And Answers Verified 100% Correct

Rating
-
Sold
-
Pages
12
Grade
A+
Uploaded on
17-11-2025
Written in
2025/2026

USABO Open Exam Questions And Answers Verified 100% Correct If one were to follow the path of a human erythrocyte starting from an artery that leads to the duodenum, the erythrocyte will most likely pass through ___ capillary beds before reaching the right ventricle of the heart. A. 1 B. 2 C. 3 D. 4 E. 5 - ANSWER -D. 4 While conducting research on Euglena, a researcher observed that the contractile vacuole ceased functioning yet the rest of the organism seemed healthy and active. Which of the following is MOST likely responsible for the cessation of contractile vacuole action? A. Moving the Euglena from a lighted to darkened environment. B. Moving the Euglena from a freshwater to a seawater environment. C. Moving the Euglena rom a seawater to a freshwater environment. D. Lowering the pH of the medium from 7.0 to 6.5. E. Lowering the temperature of the medium from 20°C to 15°C - ANSWER -D. Lowering the pH of the medium from 7.0 to 6.5. Last year, Katya joined five of her best friends for an adventure rafting 42 miles on the Tara River in Montenegro's Durmitor National Park. One evening, they pulled into the bank to rest and have dinner. Katya decided she would explore the area for few wild strawberries and found very few of them. She gathered all the strawberries she saw and brought them back for the group to have on their pancakes the next morning. Katya had such a wonderful time that when her friend Charles asked her to do the trip again, she readily agreed. They made port in the same spot as last year and again, Katya with Charles sought out strawberries. This time though, the hillsides were covered with wild strawberries and they gathered only the largest and most ripe berries for their pancakes. This is an example of: A. Associative learning B. Cognitive thinking C. Operant conditioning D. Optimal foraging E. Trial-and-error learning - ANSWER -D. Optimal foraging Which of the following is NOT a reason that Drosophila melanogaster was originally used as a model organism in Thomas Morgan's 1907 genetics experiments? A. Generation time is brief. B. It has only four chromosomes, which are easily visible. C. It reproduces prolifically. D. It was easy to manipulate genetically. E. It is a relatively simple organism to breed in the lab. - ANSWER -D. It was easy to manipulate genetically. Which of the following is correct? A. Acetylation of histones facilitates expression of the DNA associated with the acetylated histone. B. Methylation of DNA facilitates expression. C. G proteins attaching to histones facilitate expression of DNA. D. Deacetylation of histones facilitates expression of DNA wrapped around the acetylated histone. E. Methylation of histones facilitates expression of DNA wrapped around the acetylated histone. - ANSWER -A. Acetylation of histones facilitates expression of the DNA associated with the acetylated histone. Which of the following could NOT be the blood type of a child born to a mother with AB+ blood and a father with B- blood? A. A+ B. AB C. O+ D. A. E. AB+ - ANSWER -C. O+ X-linked agammaglobulinaemia is a rare X-linked disorder that interferes with the body's ability to fight infection. A man with X-linked agammaglobulinaemia marries a woman who is not affected. Which of the following best predicts their children's potential for inheriting X-linked agammaglobulinaemia? A. All their children, regardless of sex, will have X-linked agammaglobulinaemia. B. All their sons will have X-linked agammaglobulinaemia, and all their daughters will be carriers. C. Approximately 50% of their daughters will have X-linked agammaglobulinaemia, and all their sons will be normal. D. Approximately 50% of their sons will have X-linked agammaglobulinaemia, and all their daughters will be carriers. E. None of their children will have X-linked agammaglobulinaemia, but their daughters will be carriers. - ANSWER -E. None of their children will have X linked agammaglobulinaemia, but their daughters will be carriers. In a population of papillons that contains genetic variation under the influence of natural selection, what is the correct sequence of the following events? I. Allele frequency within the population change. II. Differential reproduction occurs. III. Environmental changes occur. IV. New selective pressures occur. A. IV, III, II, I B. IV, III, I, II C. III, II, IV, I D. III, IV, II, I E. III, IV, I, II - ANSWER -D. III, IV, II, I Which of the following pairs represent two distinct species? A. House mouse, Fancy mouse B. Mayan Indian, Inuit Indian C. Monarch butterfly, Viceroy butterfly D. Papillon, Chihauhau E. Soldier ant, Drone ant - ANSWER -C. Monarch butterfly, Viceroy butterfly Olney, IL, is known for its white squirrel population. In this squirrel population, assume that 10% of the genes are for albino coat color and 90% are for gray coat. If HardyWeinberg assumptions are true, what percentage of the squirrels are heterozygous? A. 90 B. 81 C. 18 D. 9 E. 1 - ANSWER -C. 18 Evolution of Batesian mimicry is dependent upon A. Brain-controlled deposition of pigment by the mimic in response to seeing the model. B. Evolution by the model and the mimic of similar adaptations to the same selection pressures.

Show more Read less
Institution
USABO Open
Course
USABO Open









Whoops! We can’t load your doc right now. Try again or contact support.

Written for

Institution
USABO Open
Course
USABO Open

Document information

Uploaded on
November 17, 2025
Number of pages
12
Written in
2025/2026
Type
Exam (elaborations)
Contains
Questions & answers

Subjects

Content preview

USABO Open Exam Questions And Answers
Verified 100% Correct


If one were to follow the path of a human erythrocyte starting from an artery that
leads to the duodenum, the erythrocyte will most likely pass through ___ capillary
beds before reaching the right ventricle of the heart.

A. 1 B. 2 C. 3 D. 4 E. 5 - ANSWER -D. 4

While conducting research on Euglena, a researcher observed that the contractile
vacuole ceased functioning yet the rest of the organism seemed healthy and active.
Which of the following is MOST likely responsible for the cessation of contractile
vacuole action?

A. Moving the Euglena from a lighted to darkened environment.
B. Moving the Euglena from a freshwater to a seawater environment.
C. Moving the Euglena rom a seawater to a freshwater environment.
D. Lowering the pH of the medium from 7.0 to 6.5.
E. Lowering the temperature of the medium from 20°C to 15°C - ANSWER -D.
Lowering the pH of the medium from 7.0 to 6.5.

Last year, Katya joined five of her best friends for an adventure rafting 42 miles
on the Tara River in Montenegro's Durmitor National Park. One evening, they
pulled into the bank to rest and have dinner. Katya decided she would explore the
area for few wild strawberries and found very few of them. She gathered all the
strawberries she saw and brought them back for the group to have on their
pancakes the next morning. Katya had such a wonderful time that when her friend
Charles asked her to do the trip again, she readily agreed. They made port in the
same spot as last year and again, Katya with Charles sought out strawberries. This
time though, the hillsides were covered with wild strawberries and they gathered
only the largest and most ripe berries for their pancakes. This is an example of:

A. Associative learning
B. Cognitive thinking
C. Operant conditioning
D. Optimal foraging

, E. Trial-and-error learning - ANSWER -D. Optimal foraging

Which of the following is NOT a reason that Drosophila melanogaster was
originally used as a model organism in Thomas Morgan's 1907 genetics
experiments?

A. Generation time is brief.
B. It has only four chromosomes, which are easily visible.
C. It reproduces prolifically.
D. It was easy to manipulate genetically.
E. It is a relatively simple organism to breed in the lab. - ANSWER -D. It was
easy to manipulate genetically.

Which of the following is correct?

A. Acetylation of histones facilitates expression of the DNA associated with the
acetylated histone.
B. Methylation of DNA facilitates expression.
C. G proteins attaching to histones facilitate expression of DNA.
D. Deacetylation of histones facilitates expression of DNA wrapped around the
acetylated histone.
E. Methylation of histones facilitates expression of DNA wrapped around the
acetylated histone. - ANSWER -A. Acetylation of histones facilitates expression
of the DNA associated with the acetylated histone.

Which of the following could NOT be the blood type of a child born to a mother
with AB+ blood and a father with B- blood?

A. A+ B. AB C. O+ D. A. E. AB+ - ANSWER -C. O+

X-linked agammaglobulinaemia is a rare X-linked disorder that interferes with the
body's ability to fight infection. A man with X-linked agammaglobulinaemia
marries a woman who is not affected. Which of the following best predicts their
children's potential for inheriting X-linked agammaglobulinaemia?

A. All their children, regardless of sex, will have X-linked agammaglobulinaemia.
B. All their sons will have X-linked agammaglobulinaemia, and all their daughters
will be carriers.
C. Approximately 50% of their daughters will have X-linked
agammaglobulinaemia, and all their sons will be normal.
$13.49
Get access to the full document:

100% satisfaction guarantee
Immediately available after payment
Both online and in PDF
No strings attached

Get to know the seller
Seller avatar
TopGradeGuru
1.5
(2)

Get to know the seller

Seller avatar
TopGradeGuru Teachme2-tutor
View profile
Follow You need to be logged in order to follow users or courses
Sold
10
Member since
1 year
Number of followers
0
Documents
2429
Last sold
1 month ago
GRADEHUB

We provide access to a wide range of professionally curated exams for students and educators. It offers high-quality, up-to-date assessment materials tailored to various subjects and academic levels. With instant downloads and affordable pricing, it's the go-to resource for exam preparation and academic success.

1.5

2 reviews

5
0
4
0
3
0
2
1
1
1

Recently viewed by you

Why students choose Stuvia

Created by fellow students, verified by reviews

Quality you can trust: written by students who passed their tests and reviewed by others who've used these notes.

Didn't get what you expected? Choose another document

No worries! You can instantly pick a different document that better fits what you're looking for.

Pay as you like, start learning right away

No subscription, no commitments. Pay the way you're used to via credit card and download your PDF document instantly.

Student with book image

“Bought, downloaded, and aced it. It really can be that simple.”

Alisha Student

Frequently asked questions