which vitamin is produced when the skin is exposed to sunlight

ATI TEAS 7

Practice TEAS Science Test

1. Which vitamin is produced when the skin is exposed to sunlight?

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

Correct answer: B

Rationale: Vitamin D is the correct answer. When the skin is exposed to sunlight, it triggers a process where a form of cholesterol in the skin is converted into vitamin D. This vitamin plays a crucial role in aiding calcium absorption in the gut, which is essential for maintaining strong and healthy bones. Vitamin A (Choice A) is important for vision and immune function but is not produced by sunlight exposure. Vitamin K (Choice C) is known for its role in blood clotting and bone metabolism, but it is not produced by sunlight. Vitamin E (Choice D) is an antioxidant that protects cells from damage but is not synthesized in the skin through sunlight exposure.

2. What is the structure that attaches to each chromosome during mitosis?

A. Centromere
B. Telomere
C. Spindle apparatus
D. Nucleolus

Correct answer: A

Rationale: The correct answer is the centromere. It is the structure that attaches to each chromosome during mitosis. The centromere serves as the attachment point for spindle fibers during cell division, ensuring proper distribution of chromosomes to daughter cells. Telomeres are found at the ends of chromosomes, providing protection and stability. The spindle apparatus is responsible for separating chromosomes during cell division. The nucleolus, located within the nucleus, is involved in ribosomal RNA synthesis and not in chromosome attachment during mitosis.

3. What is the term for the mixture of reactants and products present during a chemical reaction?

A. Solution
B. Mixture
C. Reaction mixture
D. Precipitate

Correct answer: C

Rationale: The term 'reaction mixture' is used to describe the combination of both reactants and products that exist simultaneously during a chemical reaction. It encompasses not only the initial substances (reactants) but also the resulting compounds (products) formed throughout the reaction process. Choice A, 'Solution,' typically refers to a homogenous mixture where one substance is dissolved in another. Choice B, 'Mixture,' is a general term that does not specifically indicate the mix of reactants and products in a chemical reaction. Choice D, 'Precipitate,' specifically refers to the solid formed when two solutions react and a solid compound is produced.

4. Centrioles are structures involved in cell division. What is their specific role?

A. Forming the nuclear envelope
B. Replicating DNA
C. Organizing microtubules during cell division
D. Protein synthesis

Correct answer: C

Rationale: Centrioles are involved in organizing microtubules during cell division, specifically in forming the mitotic spindle. The mitotic spindle is crucial for the proper alignment and separation of chromosomes during cell division, ensuring the accurate distribution of genetic material to daughter cells. Choice A, forming the nuclear envelope, is incorrect as centrioles do not have a direct role in this process. Choice B, replicating DNA, is incorrect as centrioles are not involved in DNA replication. Choice D, protein synthesis, is incorrect as centrioles do not play a role in protein synthesis.

5. Which of the following is an end product of cellular respiration?

A. Oxygen
B. ATP energy
C. Carbon dioxide
D. Water

Correct answer: B

Rationale: The correct answer is B: ATP energy. During cellular respiration, glucose is broken down to produce ATP, which is the primary energy currency of cells. While oxygen is required for cellular respiration to occur, it is not an end product but rather a reactant. Carbon dioxide and water are byproducts of cellular respiration, alongside ATP. Therefore, options A, C, and D are incorrect as they are not end products of cellular respiration.