1. The hypothalamus, a part of the brain, plays a crucial role in endocrine regulation. It secretes GnRH (Gonadotropin-releasing hormone) which stimulates the pituitary gland to produce FSH and LH. What is the MAIN function of FSH and LH?

A. Regulate blood sugar levels
B. Control growth and development
C. Stimulate the fight-or-flight response
D. Maintain calcium homeostasis

Correct answer: B

Rationale: The correct answer is B: 'Control growth and development.' FSH (Follicle-stimulating hormone) and LH (Luteinizing hormone) are essential hormones produced by the pituitary gland in response to GnRH from the hypothalamus. FSH plays a key role in stimulating the growth and development of ovarian follicles in females and sperm production in males. LH triggers ovulation in females and stimulates the production of testosterone in males. These hormones are crucial for the reproductive system and play a major role in controlling growth and development during puberty and throughout adulthood. Therefore, the main function of FSH and LH is not to regulate blood sugar levels, stimulate the fight-or-flight response, or maintain calcium homeostasis, making options A, C, and D incorrect.

2. What is the term for a solution that contains the maximum amount of solute that can dissolve at a specific temperature and pressure?

A. Saturated solution
B. Unsaturated solution
C. Dilute solution
D. Concentrated solution

Correct answer: A

Rationale: A saturated solution is one in which the maximum amount of solute has dissolved under specific conditions. The other choices do not accurately describe a saturated solution.

3. The tiny contractile units within muscle cells are called:

A. Myocytes
B. Myofibrils
C. Sarcomeres
D. Tendons

Correct answer: C

Rationale: The correct answer is C: Sarcomeres. Sarcomeres are the basic contractile units within muscle cells. They are made up of overlapping filaments of actin and myosin proteins, which slide past each other during muscle contraction, resulting in muscle movement. Myocytes (A) are muscle cells, myofibrils (B) are cylindrical structures within muscle fibers composed of sarcomeres, and tendons (D) are tough bands of connective tissue that connect muscle to bone. Therefore, sarcomeres are specifically responsible for muscle contraction within muscle cells.

4. What is the structure that attaches to each chromosome during mitosis?

A. Centromere
B. Telomere
C. Spindle apparatus
D. Nucleolus

Correct answer: A

Rationale: Rationale: The centromere is the structure that attaches to each chromosome during mitosis. It is a region of the chromosome where the two sister chromatids are held together and where the spindle fibers attach during cell division. The centromere plays a crucial role in ensuring that each daughter cell receives the correct number of chromosomes during cell division. Telomeres are structures found at the ends of chromosomes that protect them from deterioration and fusion with neighboring chromosomes. The spindle apparatus is a structure made of microtubules that helps separate chromosomes during cell division. The nucleolus is a region within the nucleus where ribosomal RNA synthesis occurs and is not directly involved in chromosome attachment during mitosis.

5. Which hormone stimulates the release of pancreatic enzymes and bile?

A. Gastrin
B. Insulin
C. Cholecystokinin (CCK)
D. Glucagon

Correct answer: C

Rationale: The correct answer is C: Cholecystokinin (CCK). Cholecystokinin is a hormone produced by the small intestine in response to the presence of food, especially fats and proteins. It stimulates the release of pancreatic enzymes from the pancreas and bile from the gallbladder to aid in digestion. Gastrin is a hormone that stimulates the release of gastric acid in the stomach. Insulin and glucagon are hormones involved in regulating blood sugar levels, not the release of pancreatic enzymes and bile. Therefore, CCK is the hormone responsible for stimulating the release of pancreatic enzymes and bile in the digestive process.

6. What happens during a physical change in matter?

A. A new substance with different properties is formed
B. The chemical composition of the substance changes
C. The original substance can be recovered by physical means
D. Energy is either released or absorbed

Correct answer: C

Rationale: During a physical change in matter, the original substance undergoes a change in its physical state or appearance without any change in its chemical composition. This means that the original substance can be recovered by physical means, such as melting, freezing, boiling, or condensing. No new substance is formed (option A), the chemical composition remains the same (option B), and energy changes can occur but are not a defining characteristic of a physical change (option D).