1. Which division of the nervous system is responsible for involuntary functions such as heart rate, digestion, and respiratory rate?

A. Somatic nervous system
B. Autonomic nervous system
C. Peripheral nervous system
D. Central nervous system

Correct answer: b

Rationale: The correct answer is B: Autonomic nervous system. The autonomic nervous system is responsible for regulating involuntary functions in the body, such as heart rate, digestion, respiratory rate, and other automatic processes. The somatic nervous system (A) controls voluntary muscle movements, the peripheral nervous system (C) consists of nerves outside the brain and spinal cord, and the central nervous system (D) includes the brain and spinal cord. Understanding the functions and divisions of the nervous system is crucial for grasping how different bodily processes are controlled and regulated.

2. What is the difference between polygenic inheritance and pleiotropy?

A. Polygenic inheritance involves multiple genes influencing one trait, while pleiotropy involves one gene affecting multiple traits.
B. Polygenic inheritance is found in simple Mendelian traits, while pleiotropy is found in complex traits.
C. Polygenic inheritance is always quantitative, while pleiotropy can be qualitative or quantitative.
D. Both involve multiple genes and multiple traits, but the specific mechanisms differ

Correct answer: A

Rationale: Rationale: - Polygenic inheritance refers to the situation where a trait is influenced by multiple genes, each contributing a small effect to the phenotype. These traits often show continuous variation and are not easily categorized into discrete categories. - Pleiotropy, on the other hand, occurs when a single gene influences multiple, seemingly unrelated traits. This means that a mutation in one gene can lead to multiple phenotypic effects across different traits or characteristics. - Therefore, the key difference between polygenic inheritance and pleiotropy lies in the number of genes involved in influencing a trait (multiple genes in polygenic inheritance vs. one gene in pleiotropy) and the direction of influence (one trait affected by multiple genes in polygenic inheritance vs. multiple traits affected by one gene in pleiotropy).

3. The fluid-filled sacs that cushion the brain within the skull are called:

A. Meninges
B. Cerebrospinal fluid
C. Dura mater
D. Arachnoid mater

Correct answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. Cerebrospinal fluid is a clear, colorless fluid that surrounds the brain and spinal cord, acting as a cushion to protect the central nervous system from injury. Meninges (Option A) are the protective membranes that cover the brain and spinal cord, while the dura mater (Option C) and arachnoid mater (Option D) are specific layers of the meninges. However, cerebrospinal fluid is the fluid-filled sac that directly cushions the brain within the skull, making it the most appropriate answer for this question.

4. Which organelle is responsible for cellular respiration, producing ATP for energy?

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

Correct answer: B

Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell because they are responsible for cellular respiration, a process that produces ATP (adenosine triphosphate) for energy. The other organelles listed, such as the nucleus, Golgi apparatus, and vacuole, do not play a direct role in cellular respiration or ATP production. The mitochondria contain specialized structures like cristae and enzymes that carry out the biochemical reactions of cellular respiration, making them essential for energy production in the cell.

5. The human eye focuses light by adjusting the shape of its:

A. Cornea
B. Iris
C. Lens
D. Retina

Correct answer: C

Rationale: The human eye focuses light by adjusting the shape of its lens. The cornea is the transparent outer covering of the eye that helps to focus light, but it does not change shape. The iris regulates the amount of light entering the eye through the pupil but does not adjust the shape of the light. The retina is the layer at the back of the eye that receives and processes light signals but does not play a role in focusing light. Therefore, the correct answer is C, the lens, as it changes shape to focus light onto the retina, allowing for clear vision.