how does rna polymerase differ from dna polymerase

ATI TEAS 7

TEAS 7 science study guide free

1. How does RNA polymerase differ from DNA polymerase?

A. Both enzymes are identical in function and structure.
B. RNA polymerase does not require a primer to initiate RNA synthesis.
C. RNA polymerase can synthesize both RNA and DNA.
D. RNA polymerase can only synthesize RNA, unlike DNA polymerase.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA polymerase and DNA polymerase are not identical in function and structure. They have different roles in the cell. B) This statement is correct. Unlike DNA polymerase, RNA polymerase does not require a primer to initiate RNA synthesis. RNA polymerase can start the synthesis of RNA de novo. C) This statement is incorrect. RNA polymerase is specialized for synthesizing RNA, not DNA. DNA polymerase is responsible for synthesizing DNA. D) This statement is correct. RNA polymerase can only synthesize RNA, while DNA polymerase is responsible for synthesizing DNA.

2. What causes lymphedema, a chronic condition, to occur?

A. Inflammation of lymph nodes
B. Blockage of lymph vessels
C. Malfunction of the spleen
D. Decrease in bone marrow production

Correct answer: B

Rationale: Lymphedema is a chronic condition that occurs when lymph vessels become blocked, leading to swelling and fluid retention in the affected area. Inflammation of lymph nodes, spleen malfunction, or decreased bone marrow production are not directly associated with the development of lymphedema. Lymph vessels play a crucial role in carrying lymphatic fluid, and when they are blocked, it disrupts the normal flow of fluid, resulting in lymphedema. Therefore, the correct answer is that lymphedema occurs when lymph vessels become blocked.

3. Which part of the brain is responsible for regulating body temperature, hunger, and thirst, and is considered a key player in the endocrine system?

A. Amygdala
B. Hippocampus
C. Hypothalamus
D. Thalamus

Correct answer: C

Rationale: The hypothalamus is responsible for regulating body temperature, hunger, and thirst, making it a vital component in maintaining homeostasis. It also plays a crucial role in the endocrine system by controlling the release of hormones from the pituitary gland. The amygdala primarily processes emotions, the hippocampus is associated with memory formation, and the thalamus acts as a relay station for sensory information. Therefore, the hypothalamus is the correct answer as it directly regulates the physiological processes mentioned in the question.

4. What is the role of the diaphragm in respiration?

A. To regulate air pressure in the lungs
B. To contract and expand the lungs
C. To store oxygen
D. To break down carbon dioxide

Correct answer: B

Rationale: The correct answer is B. The diaphragm plays a crucial role in respiration by contracting and expanding the lungs. When the diaphragm contracts, it moves downward, creating more space in the chest cavity and allowing the lungs to expand. This expansion leads to a decrease in pressure inside the lungs, causing air to rush in. When the diaphragm relaxes, it moves back up, decreasing the space in the chest cavity and causing the lungs to deflate. This action increases the pressure in the lungs, leading to air being pushed out. Therefore, the diaphragm's main function is to facilitate the inhalation and exhalation of air by contracting and expanding the lungs. Choices A, C, and D are incorrect because the diaphragm's primary function is not to regulate air pressure in the lungs, store oxygen, or break down carbon dioxide. Instead, its main purpose is to aid in the mechanical process of breathing.

5. When is a solution considered saturated?

A. More solute cannot be dissolved
B. The solvent starts to evaporate
C. The solution becomes cloudy
D. It reaches a specific temperature

Correct answer: A

Rationale: A solution is considered saturated when it has dissolved the maximum amount of solute that can be dissolved at a given temperature. At this point, adding more solute will not result in further dissolution, indicating that the solution is saturated. The other choices are incorrect because the solvent evaporating or the solution becoming cloudy are not definitive indicators of a saturated solution. Additionally, reaching a specific temperature does not determine saturation, as the solubility of a solute can vary with temperature. Therefore, the correct answer is that more solute cannot be dissolved in a saturated solution.