1. The main function of the nephrons is to:

A. Store urine
B. Filter blood and remove waste products
C. Produce hormones
D. Control blood pressure

Correct answer: B

Rationale: The correct answer is B: 'Filter blood and remove waste products.' Nephrons are the functional units of the kidneys responsible for filtering blood to remove waste products, excess ions, and water, while reabsorbing essential substances like glucose and amino acids. This process forms urine, which is stored in the bladder before being excreted. Options A, C, and D are incorrect because nephrons do not store urine, produce hormones, or directly control blood pressure; although the kidneys do play a role in long-term blood pressure regulation through mechanisms like the renin-angiotensin-aldosterone system.

2. The major site for nutrient absorption in the digestive system is the:

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: C

Rationale: The correct answer is C: Small intestine. The small intestine is the major site for nutrient absorption in the digestive system. It is where most of the digestion and absorption of nutrients from food takes place. The small intestine has villi and microvilli that increase its surface area, allowing for efficient absorption of nutrients like sugars, amino acids, and fatty acids into the bloodstream. The mouth is primarily responsible for mechanical digestion through chewing, while the stomach's main function is to break down food with enzymes and acids. The large intestine mainly absorbs water and electrolytes, with minimal nutrient absorption.

3. Which of the following joints allows for side-to-side bending movements?

A. Hinge joint
B. Ball-and-socket joint
C. Gliding joint
D. Saddle joint

Correct answer: C

Rationale: The correct answer is C: Gliding joint. Gliding joints are found where the bones meet and allow for limited side-to-side and back-and-forth movements. These joints have flat or slightly curved surfaces that glide against each other, enabling smooth motion in multiple directions. Hinge joints (A) allow for movement in one plane like a door hinge, ball-and-socket joints (B) allow for a wide range of motion in multiple directions, and saddle joints (D) allow for back-and-forth and side-to-side movements but are primarily designed for flexion and extension like the joint at the base of the thumb.

4. Deficiency of which hormone can lead to stunted growth and developmental delays in children?

A. Estrogen
B. Testosterone
C. Growth hormone
D. Insulin

Correct answer: C

Rationale: The correct answer is C: Growth hormone. Growth hormone plays a crucial role in stimulating growth, cell reproduction, and regeneration in humans. Deficiency of growth hormone can lead to stunted growth and developmental delays in children. Estrogen and testosterone are sex hormones responsible for sexual development and characteristics, but they do not directly impact growth. Insulin is a hormone that regulates blood sugar levels and is not associated with stunted growth or developmental delays.

5. What is the functional group present in amines?

A. Hydroxyl
B. Carbonyl
C. Amine
D. Nitro

Correct answer: C

Rationale: Amines have the functional group -NHÃ¢â€šâ€š. The other choices are associated with different functional groups.

6. What are the key differences between cytokinesis in plant and animal cells?

A. Animal cells utilize an actomyosin ring for cleavage furrow formation, while plant cells lack this mechanism.
B. Plant cells rely on the assembly of a cell plate in the center of the dividing cell, ultimately separating the cytoplasm.
C. Cytokinesis in both plant and animal cells is driven by the expansion of the endoplasmic reticulum.
D. Both types of cells achieve cytokinesis through similar membrane pinching and constriction mechanisms.

Correct answer: B

Rationale: Rationale: A) Animal cells utilize an actomyosin ring for cleavage furrow formation, while plant cells lack this mechanism. - This statement is true. Animal cells use an actomyosin ring to form a cleavage furrow during cytokinesis, while plant cells do not have this mechanism. Instead, plant cells form a cell plate. B) Plant cells rely on the assembly of a cell plate in the center of the dividing cell, ultimately separating the cytoplasm. - This statement is correct. Plant cells form a cell plate in the middle of the dividing cell during cytokinesis. The cell plate eventually develops into a new cell wall that separates the two daughter cells. C) Cytokinesis in both plant and animal cells is driven by the expansion of the endoplasmic reticulum. - This