which of the following best describes one of the roles of rna

ATI TEAS 7

ATI TEAS 7 Science Practice Test

1. Which of the following best describes one of the roles of RNA?

A. Manufacturing the proteins needed from DNA
B. Creating the bonds between the elements that make up DNA
C. Sending messages about the correct sequence of proteins in DNA
D. Forming the identifiable double helix shape of DNA

Correct answer: C

Rationale: The correct answer is C. RNA serves as a messenger that carries instructions from DNA for protein synthesis. It does not manufacture proteins directly from DNA (choice A), create bonds within DNA (choice B), or form the double helix structure of DNA (choice D). Therefore, the primary role of RNA is to convey information about the correct sequence of proteins to be synthesized based on the DNA sequences it receives.

2. T cells in the immune system can be categorized into different types. What type of T cell directly kills infected body cells?

A. Helper T cells
B. Cytotoxic T cells
C. Regulatory T cells
D. Memory T cells

Correct answer: B

Rationale: Cytotoxic T cells directly kill infected body cells by recognizing specific antigens on the surface of infected cells and releasing cytotoxic substances to induce cell death, eliminating the infected cells. Helper T cells assist in coordinating the immune response, regulatory T cells help maintain immune tolerance, and memory T cells mount a faster and stronger response upon re-exposure to a previously encountered antigen. Therefore, the correct answer is cytotoxic T cells as they play a crucial role in directly targeting and destroying infected cells.

3. What does cytokinesis refer to?

A. Division of the nucleus
B. Division of the cytoplasm
C. Separation of chromosomes
D. Formation of spindle fibers

Correct answer: B

Rationale: Cytokinesis refers to the division of the cytoplasm of a parental cell between two daughter cells during cell division. It ensures that each daughter cell receives its share of organelles and cytoplasmic components necessary for cellular functions. Choice A, division of the nucleus, is incorrect as this process is known as mitosis. Choice C, separation of chromosomes, is incorrect as it refers to the process of chromatid separation during mitosis. Choice D, formation of spindle fibers, is incorrect as spindle fibers are involved in mitosis to separate chromosomes, not in cytokinesis.

4. What is the role of the large intestine in the digestive system?

A. To break down proteins
B. To absorb water and form feces
C. To digest fats
D. To neutralize stomach acid

Correct answer: B

Rationale: The correct answer is B. The large intestine plays a crucial role in absorbing water from indigestible food matter and forming feces for elimination. Choice A is incorrect because the breakdown of proteins primarily occurs in the stomach and small intestine. Choice C is incorrect as the digestion of fats primarily occurs in the small intestine. Choice D is incorrect as neutralizing stomach acid is mainly the function of the stomach lining and not the large intestine.

5. Which organ produces bile to aid in digestion?

A. Pancreas
B. Liver
C. Gallbladder
D. Stomach

Correct answer: B

Rationale: The correct answer is B: Liver. The liver produces bile, which is stored in the gallbladder and released into the small intestine to aid in the digestion and absorption of fats. The pancreas secretes digestive enzymes, not bile. The gallbladder stores bile but does not produce it. The stomach produces gastric juices, not bile, to aid in digestion.