when animals eat insulin is released from the pancreas stimulating glucose uptake by the liver when glucose levels drop the pancreas reduces insulin r

ATI TEAS 7

ATI TEAS Science Test

1. When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

A. Negative feedback.
B. Positive feedback.
C. Stress response.
D. Parasympathetic regulation.

Correct answer: A

Rationale: This mechanism is an example of negative feedback. Negative feedback systems work to counteract changes in the body and maintain a stable internal environment (homeostasis). In this case, the release of insulin in response to high glucose levels is followed by a reduction in insulin release when glucose levels drop. This response helps regulate glucose levels and return them to a normal range, demonstrating the characteristic of negative feedback where the body's response opposes the initial stimulus to maintain equilibrium. Positive feedback would amplify the initial change rather than counteract it, so it is not the correct choice. Stress response and parasympathetic regulation are not directly involved in this glucose regulation process, making them incorrect choices.

2. Which cellular organelle is used for digestion to recycle materials?

A. The Golgi apparatus
B. The lysosome
C. The centrioles
D. The mitochondria

Correct answer: B

Rationale: The lysosome is the correct cellular organelle used for digestion to recycle materials. Lysosomes contain enzymes that break down waste materials, cellular debris, and ingested substances. This process helps in recycling nutrients and maintaining cellular homeostasis. The Golgi apparatus is involved in processing and packaging proteins, the centrioles play a role in cell division, and the mitochondria are responsible for energy production. However, none of these organelles are primarily used for digestion and recycling of materials within the cell.

3. What is the process by which a population gradually loses genetic variation?

A. Founder effect
B. Bottleneck effect
C. Gene flow
D. Speciation

Correct answer: B

Rationale: A) Founder effect: This occurs when a small group of individuals establishes a new population, leading to a loss of genetic variation compared to the original population. It does not necessarily result in a gradual loss of genetic variation in an existing population. B) Bottleneck effect: This process occurs when a population is drastically reduced in size, leading to a significant loss of genetic variation due to the limited number of individuals contributing to the gene pool. The reduced genetic diversity can have long-term effects on the population's ability to adapt to environmental changes. C) Gene flow: This refers to the movement of genes between populations, which can introduce new genetic variation and prevent populations from diverging. Gene flow does not lead to a gradual loss of genetic variation within a population. D) Speciation: This is the process by which new species evolve from existing species, often involving the accumulation of genetic differences that l

4. What is the dermis composed of?

A. Adipose tissue
B. Epithelial cells
C. Connective tissue
D. Muscle tissue

Correct answer: C

Rationale: The correct answer is C: Connective tissue. The dermis is primarily composed of connective tissue, which includes collagen and elastin fibers that provide strength and elasticity to the skin. It houses blood vessels, nerve endings, hair follicles, and glands, playing a crucial role in supporting the skin structure and function. Adipose tissue (choice A) is found in the subcutaneous layer beneath the dermis, providing insulation and energy storage. Epithelial cells (choice B) form the outermost layer of the skin called the epidermis. Muscle tissue (choice D) is not a significant component of the dermis but is found deeper in the body associated with movement and support.

5. Which of the following is responsible for the body's fight-or-flight response?

A. Pancreas
B. Adrenal glands
C. Thyroid gland
D. Pituitary gland

Correct answer: B

Rationale: The correct answer is B: Adrenal glands. The adrenal glands are responsible for the body's fight-or-flight response. During stressful situations, the adrenal glands release hormones like adrenaline and noradrenaline, initiating the fight-or-flight response. These hormones prepare the body to either confront or flee from a perceived threat.\nChoice A - Pancreas: The pancreas is primarily responsible for producing insulin and regulating blood sugar levels, not the fight-or-flight response.\nChoice C - Thyroid gland: The thyroid gland is responsible for producing hormones that regulate metabolism, not directly involved in the fight-or-flight response.\nChoice D - Pituitary gland: The pituitary gland regulates various endocrine functions by releasing hormones, but it is not the primary gland responsible for the fight-or-flight response.