which statement most accurately compares and contrasts the structures of dna and rna

ATI TEAS 7

ATI TEAS 7 Science Practice Test

1. Which statement most accurately compares and contrasts the structures of DNA and RNA?

A. Both DNA and RNA have 4 nucleotide bases. Three of the bases are the same, but the fourth base is thymine in DNA and uracil in RNA.
B. Both DNA and RNA have the same 4 nucleotide bases. However, the nucleotides bond differently in DNA compared to RNA.
C. Both DNA and RNA have different numbers of nucleotide bases. DNA is a double helix while RNA is a single strand.
D. Both DNA and RNA have a double helix structure. However, DNA contains 6 nucleotide bases and RNA contains 4 nucleotide bases.

Correct answer: A

Rationale: The correct answer is A because DNA and RNA both consist of 4 nucleotide bases, namely adenine, cytosine, and guanine, which are common in both. The key difference lies in the fourth base, which is thymine in DNA and uracil in RNA. This distinction is fundamental in understanding the structural variances between DNA and RNA. Choice B is incorrect as it incorrectly states that the nucleotides bond differently in DNA compared to RNA without specifying the crucial base differences. Choice C is inaccurate as it misrepresents the numbers of nucleotide bases in DNA and RNA, and incorrectly describes DNA as a double helix and RNA as a single strand, which is not related to the difference in bases. Choice D is incorrect as it inaccurately portrays DNA with 6 nucleotide bases and RNA with 4, which is not true; both DNA and RNA have 4 nucleotide bases, but with differences in one of the bases.

2. What is the term for the division of the cytoplasm?

A. Cytokinesis
B. Mitosis
C. Meiosis
D. Apoptosis

Correct answer: A

Rationale: Cytokinesis is the correct term for the division of the cytoplasm during cell division. It is the final stage of cell division, following either mitosis or meiosis, where the cytoplasm of a parent cell is divided into two daughter cells. Mitosis is the process of nuclear division, while meiosis is a type of cell division that results in four daughter cells with half the number of chromosomes of the parent cell. Apoptosis, on the other hand, is programmed cell death and not the division of the cytoplasm.

3. What is the primary function of the lymphatic system?

A. Transporting nutrients throughout the body
B. Removing excess fluids and waste products from tissues
C. Producing red blood cells
D. Regulating body temperature

Correct answer: B

Rationale: The primary function of the lymphatic system is to remove excess fluids, waste products, and toxins from tissues. It maintains fluid balance and supports the immune system by transporting lymph, which contains white blood cells, throughout the body. Choice A is incorrect as nutrient transport is primarily handled by the circulatory system. Choice C is incorrect because red blood cells are produced in the bone marrow, not the lymphatic system. Choice D is incorrect as the regulation of body temperature is mainly controlled by the endocrine system and thermoregulatory mechanisms in the body. Therefore, the correct answer is B.

4. Which of the following is true regarding adipocytes?

A. They are involved in the secretion of glucose.
B. They are responsible for storing the fat found in adipose tissue.
C. They are critical in the digestive breakdown of fat.
D. They are the foundational element of muscles.

Correct answer: B

Rationale: The correct answer is B. Adipocytes are responsible for storing the fat found in adipose tissue. These specialized cells store energy in the form of fat and play a key role in energy balance and metabolism. Adipocytes do not secrete glucose; that function is typically attributed to other cells like pancreatic beta cells. Adipocytes are not involved in the digestive breakdown of fat, as this process primarily occurs in the gastrointestinal system with the help of enzymes. Adipocytes are distinct from the foundational elements of muscles, which are primarily made up of muscle fibers and associated connective tissues.

5. Chyle, a milky white fluid, is transported by lymphatic vessels from the:

A. Lungs
B. Intestines
C. Kidneys
D. Skin

Correct answer: B

Rationale: Chyle, a milky white fluid, is formed in the small intestine during digestion. It is composed of lymph and emulsified fats. Lymphatic vessels in the intestines, specifically lacteals, transport chyle from the intestines to the bloodstream for the distribution of nutrients throughout the body. The transport of chyle from the lungs, kidneys, or skin is not correct as these organs are not primarily involved in the production or transportation of chyle.