what is the primary function of ribosomes in the cell

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. What is the primary function of ribosomes in the cell?

A. To synthesize lipids and other cellular components
B. To package and transport proteins
C. To break down macromolecules
D. To translate mRNA into proteins

Correct answer: D

Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C are incorrect as they do not accurately describe the primary function of ribosomes. Choice A is incorrect because the synthesis of lipids and other cellular components is not the primary function of ribosomes. Choice B is incorrect as packaging and transporting proteins are functions typically associated with the endoplasmic reticulum and Golgi apparatus. Choice C is incorrect because ribosomes do not break down macromolecules; instead, they are involved in building proteins from amino acids.

2. Which vitamin plays a crucial role in calcium absorption in the small intestine?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin E

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D plays a crucial role in calcium absorption in the small intestine by enhancing the absorption of calcium and phosphorus. This helps in regulating the levels of these minerals in the body, which are essential for maintaining healthy bones. Vitamin A (Choice A) is important for vision and immune function, but it is not directly related to calcium absorption. Vitamin C (Choice B) is primarily known for its role in collagen synthesis and antioxidant functions, not calcium absorption. Vitamin E (Choice D) acts as an antioxidant and is not directly involved in calcium absorption in the small intestine.

3. Which of the following structures is responsible for transmitting electrical impulses in the nervous system?

A. Neuron
B. Axon
C. Myelin
D. Dendrite

Correct answer: A

Rationale: The correct answer is A: Neuron. Neurons are specialized cells that transmit electrical impulses in the nervous system. While the axon is the part responsible for conducting these impulses over long distances, it is the neuron as a whole that is ultimately responsible for transmitting electrical impulses. Myelin is a fatty substance that surrounds and insulates axons, speeding up signal transmission. Dendrites, on the other hand, receive signals from other neurons. Therefore, although the axon plays a significant role in transmission, the neuron is the fundamental unit responsible for transmitting electrical impulses in the nervous system.

4. Divide 4/3 by 9/13 and reduce the fraction.

A. 52/27
B. 51/27
C. 52/29
D. 51/29

Correct answer: A

Rationale: To divide fractions, you multiply the first fraction by the reciprocal of the second fraction. So, (4/3) ÷ (9/13) = (4/3) * (13/9) = 52/27. This fraction is already in its reduced form, making choice A the correct answer. Choices B, C, and D are incorrect as they do not represent the correct result of dividing the fractions 4/3 by 9/13.

5. Which part of the hair is not attached to the follicle?

A. Bulb
B. Root
C. Shaft
D. Strand

Correct answer: C

Rationale: The correct answer is C, 'Shaft.' The hair shaft is the part of the hair that extends above the skin surface and is not attached to the follicle. The bulb and root are parts that are connected to the follicle as they are located below the skin surface and play a role in hair growth. The strand, on the other hand, refers to a single hair fiber and is not a distinct part of the hair anatomy.