which molecule is primarily responsible for storing energy in cells

HESI A2

HESI A2 Practice Test Biology

1. Which molecule is primarily responsible for storing energy in cells?

A. Glucose
B. ATP
C. Fatty acids
D. Starch

Correct answer: B

Rationale: ATP is the correct answer because it is the molecule responsible for storing and providing energy in cells. Glucose is a source of energy but not primarily for storage. Fatty acids are more involved in energy production through oxidation. Starch is a polysaccharide used for energy storage in plants.

2. 72 chromosomes undergo meiosis. How many chromosomes will be in each gamete?

A. 18
B. 36
C. 72
D. 144

Correct answer: A

Rationale: During meiosis, the number of chromosomes is halved in each gamete. Since 72 chromosomes undergo meiosis, each gamete will contain half of that number, which is 36 chromosomes. Therefore, the correct answer is 18 chromosomes in each gamete. Choice B (36 chromosomes) is incorrect because it represents the total number of chromosomes that undergo meiosis, not the number in each gamete. Choice C (72 chromosomes) is incorrect as it represents the initial number of chromosomes, not the number in each gamete after meiosis. Choice D (144 chromosomes) is incorrect as it doubles the initial number of chromosomes, which is not the outcome of meiosis.

3. Which cellular structure is found in animal cells but not in plant cells?

A. Centriole
B. Cytoplasm
C. Vacuole
D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A, Centriole. Centrioles are found in animal cells but not in plant cells. They play a crucial role in organizing microtubules during cell division, aiding in the formation of the mitotic spindle. Plant cells lack centrioles; instead, they utilize microtubule organizing centers to perform similar functions during cell division. Choices B, C, and D are incorrect because cytoplasm is a part of both animal and plant cells, vacuoles are found in plant cells and some animal cells, and the Golgi apparatus is present in both types of cells.

4. Which organism reproduces via spore formation?

A. Shelf fungus
B. Lemon tree
C. Smallmouth bass
D. Staphylococcus

Correct answer: A

Rationale: The correct answer is A, Shelf fungus. Shelf fungus reproduces via spore formation. Spores are tiny, reproductive cells that are released into the environment to be carried by air or water, allowing the fungus to spread and reproduce. The other choices are incorrect because Lemon tree reproduces via seeds, Smallmouth bass reproduce sexually through the fertilization of eggs by sperm, and Staphylococcus bacteria reproduce by binary fission, dividing into two identical daughter cells.

5. In an example of a male with hemophilia and a female carrier, what ratio of the offspring are predicted neither to carry nor to manifest the disease?

A. 0 females : 1 male
B. 1 female : 1 male
C. 1 female : 0 males
D. 2 females : 1 male

Correct answer: D

Rationale: In this scenario, the male offspring will inherit the Y chromosome from the father and the X chromosome from the carrier mother. As a result, they will not have the hemophilia gene. The female offspring will inherit one X chromosome from the mother, which does not carry the hemophilia gene, and one X chromosome from the father, which does not exist due to the Y chromosome. Therefore, all female offspring will not carry or manifest hemophilia, resulting in a ratio of 2 females to 1 male. Choice A is incorrect because it does not account for the female offspring. Choices B and C are incorrect as they do not reflect the correct ratio based on the inheritance pattern of hemophilia.