what is the endoplasmic reticulum

ATI TEAS 7

TEAS 7 practice test free science

1. What is the endoplasmic reticulum?

A. A network of tubules that transport proteins and lipids throughout the cell
B. A sac-like structure that stores water and nutrients
C. The site of protein synthesis
D. The site of cellular respiration

Correct answer: A

Rationale: A) The endoplasmic reticulum (ER) is a network of tubules that are involved in the transport of proteins and lipids throughout the cell. It plays a crucial role in protein synthesis, folding, and transport within the cell. The ER can be further divided into rough ER, which has ribosomes attached to its surface and is involved in protein synthesis, and smooth ER, which is involved in lipid metabolism and detoxification. Therefore, option A is the most accurate description of the endoplasmic reticulum compared to the other options provided. B) A sac-like structure that stores water and nutrients does not accurately describe the endoplasmic reticulum. While some organelles like vacuoles or vesicles may store water and nutrients, the ER's primary function is not storage. C) The site of protein synthesis is partially

2. Which term refers to a position toward the feet? For example, the foot is part of the inferior extremity.

A. Anterior
B. Posterior
C. Superior
D. Inferior

Correct answer: D

Rationale: The correct answer is 'Inferior.' 'Inferior' refers to a position located towards the feet or lower part of the body. This is the opposite of 'superior,' which indicates a position towards the head or upper part of the body. 'Anterior' refers to the front of the body, 'posterior' refers to the back of the body, making them incorrect choices in this context.

3. What happens to the force of gravity between two objects when the distance between them is doubled?

A. The force increases by a factor of 2
B. The force increases by a factor of 4
C. The force decreases by a factor of 2
D. The force decreases by a factor of 4

Correct answer: D

Rationale: According to the law of universal gravitation, the force of gravity between two objects is inversely proportional to the square of the distance between them. When the distance is doubled, the force decreases by a factor of 2 squared, which is 4. Therefore, the force decreases by a factor of 4. Choice A is incorrect because the force doesn't increase when the distance is doubled. Choice B is incorrect as the force doesn't increase but actually decreases. Choice C is incorrect as the force decreases by a factor of 4, not 2.

4. The process by which a single-celled organism divides into two identical daughter cells is called

A. Conjugation
B. Binary fission
C. Endocytosis
D. Mitosis

Correct answer: B

Rationale: Rationale: A) Conjugation is a process in which genetic material is transferred between two bacterial cells through a conjugation tube. It does not involve the division of a single-celled organism into two identical daughter cells. B) Binary fission is the process by which a single-celled organism, such as a bacterium, divides into two identical daughter cells. This is a common method of reproduction in prokaryotic organisms. C) Endocytosis is a cellular process in which cells engulf external materials by wrapping them in a vesicle. It is not a method of cell division. D) Mitosis is a type of cell division that occurs in eukaryotic cells, leading to the production of two daughter cells with identical genetic material. However, the question specifically refers to a single-celled organism, which typically undergoes binary fission for reproduction.