which part of the cell is responsible for generating energy

HESI A2

HESI A2 Anatomy and Physiology Quizlet

1. Which organelle is responsible for generating energy within a cell?

A. Nucleus
B. Ribosome
C. Mitochondria
D. Golgi apparatus

Correct answer: C

Rationale: Mitochondria are commonly referred to as the powerhouses of the cell as they are primarily responsible for generating energy through cellular respiration. This process involves converting nutrients into adenosine triphosphate (ATP), which is the main energy currency of the cell. The nucleus is responsible for storing the cell's genetic material, the ribosome is involved in protein synthesis, and the Golgi apparatus is responsible for packaging and distributing molecules produced by the cell; therefore, they are not directly involved in energy generation.

2. Which is a secondary defense for the body against pathogens?

A. Tears
B. Urine
C. Inflammation
D. Mucus

Correct answer: C

Rationale: Inflammation is a secondary defense mechanism for the body against pathogens. When tissues are injured or infected, inflammation occurs as a protective response involving increased blood flow, white blood cell migration, and tissue repair. This process helps contain and eliminate pathogens, preventing them from spreading further in the body. Tears (Choice A) are a primary defense containing lysozyme and other antimicrobial agents. Urine (Choice B) is typically considered a non-specific defense mechanism due to its flushing action in the urinary tract. Mucus (Choice D) acts as a physical barrier and traps pathogens, also considered a primary defense mechanism.

3. Why might certain young people be underweight?

A. They are growing in height faster than they are gaining weight.
B. They eat little protein and too much fat and sugar.
C. They eat several meals a day and fail to exercise enough.
D. They seldom eat a meal that contains foods from all food groups.

Correct answer: A

Rationale: Certain young people might be underweight because they are growing in height faster than they are gaining weight. During periods of rapid growth, the body's energy requirements are primarily directed towards height growth rather than weight gain, resulting in some individuals being underweight despite consuming sufficient calories. Choice B is incorrect because the question focuses on reasons related to growth rather than diet composition. Choice C is incorrect as it suggests overeating rather than the specific growth-related issue of height surpassing weight gain. Choice D is incorrect as it addresses nutritional variety rather than the growth dynamics affecting weight.

4. Which muscle is responsible for the extension of the elbow?

A. Biceps brachii
B. Triceps brachii
C. Deltoid
D. Pectoralis major

Correct answer: B

Rationale: The correct answer is B: Triceps brachii. The triceps brachii muscle is responsible for extending the elbow joint. It is located on the back of the upper arm and acts in opposition to the biceps brachii, which is responsible for elbow flexion. The deltoid muscle is primarily responsible for shoulder abduction, not elbow extension. The pectoralis major muscle is involved in movements of the shoulder joint, not the elbow.

5. Which gland is responsible for regulating metabolism and growth?

A. Thyroid gland
B. Pituitary gland
C. Adrenal gland
D. Pineal gland

Correct answer: A

Rationale: The correct answer is the Thyroid gland. The thyroid gland is responsible for regulating metabolism and growth. It produces hormones such as thyroxine (T4) and triiodothyronine (T3), which play essential roles in controlling metabolic processes, growth, and development throughout the body. Choice B, the Pituitary gland, although important for hormone regulation, is not primarily responsible for regulating metabolism and growth. Choices C and D, the Adrenal gland and Pineal gland, respectively, have different functions and are not primarily involved in regulating metabolism and growth.