1. Which of the following organs is NOT directly involved in urine production?

A. Kidneys
B. Urethra
C. Lungs
D. Bladder

Correct answer: C

Rationale: The correct answer is C: Lungs. The lungs are not directly involved in urine production. The kidneys are responsible for filtering waste products from the blood to create urine. The urethra is the tube that carries urine from the bladder out of the body. The bladder serves as a temporary storage reservoir for urine. In contrast, the lungs are primarily responsible for the exchange of gases, such as oxygen and carbon dioxide, during respiration and are not directly involved in the process of urine production.

2. What is the significance of studying pedigrees in human genetics?

A. Predicting the exact outcome of genetic crosses in humans.
B. Tracing the inheritance of complex traits with multiple contributing genes.
C. Identifying carriers of dominant genetic disorders.
D. Determining the risk of acquiring a specific mutation de novo.

Correct answer: B

Rationale: Rationale: Pedigrees are diagrams that show the relationships within a family and can be used to track the inheritance patterns of specific traits or diseases. While pedigrees can provide information on the inheritance of single gene disorders (such as identifying carriers of dominant genetic disorders, as mentioned in option C), their primary significance lies in studying complex traits with multiple contributing genes. These traits do not follow simple Mendelian inheritance patterns and are influenced by both genetic and environmental factors. By analyzing pedigrees, researchers can identify patterns of inheritance for complex traits, such as polygenic diseases or traits influenced by gene-environment interactions. Therefore, option B is the most appropriate choice as it captures the main significance of studying pedigrees in human genetics.

3. Which term describes the resistance of a substance to flow?

A. Density
B. Viscosity
C. Conductivity
D. Malleability

Correct answer: b

Rationale: Viscosity refers to the resistance of a substance to flow. Substances with high viscosity flow slowly, while those with low viscosity flow more easily.

4. The WBC (white blood cell) type responsible for the initial attack on pathogens is:

A. Red blood cells
B. Platelets
C. Phagocytes
D. Lymphocytes

Correct answer: C

Rationale: The correct answer is C: Phagocytes. Phagocytes are a type of white blood cell that plays a crucial role in the immune response by engulfing and destroying pathogens. They are the first line of defense against invading microorganisms, initiating the initial attack on pathogens. Red blood cells (option A) are responsible for carrying oxygen, not for immune responses. Platelets (option B) are involved in blood clotting. Lymphocytes (option D) are another type of white blood cell but are mainly responsible for specific immune responses rather than the initial attack on pathogens.

5. Antidiuretic hormone (ADH) plays a crucial role in regulating water balance. When ADH levels are high, what happens to urine production?

A. Urine production increases significantly
B. Urine production decreases to conserve water
C. There is no change in urine production
D. The kidneys stop producing urine altogether

Correct answer: B

Rationale: When antidiuretic hormone (ADH) levels are high, it indicates that the body needs to conserve water. ADH works by increasing the permeability of the collecting ducts in the kidneys, allowing more water to be reabsorbed back into the bloodstream. This action leads to a decrease in urine production, as the body retains more water to maintain proper fluid balance. Therefore, the correct answer is B: 'Urine production decreases to conserve water.' High levels of ADH help the body prevent dehydration by reducing the amount of water lost in urine.