1. Melanin, the pigment responsible for skin color, is produced by

A. Keratinocytes (These cells produce keratin)
B. Melanocytes
C. Sebocytes (These cells produce sebum)
D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: The correct answer is B: Melanocytes. Melanin, the pigment responsible for skin color, is produced by melanocytes, which are specialized cells located in the skin's epidermis. Melanocytes transfer melanin to keratinocytes, the predominant cell type in the epidermis, where it provides protection against UV radiation. Sebocytes produce sebum, an oily substance that helps moisturize the skin and hair. Langerhans cells are a type of immune cell that play a role in the skin's immune response. Therefore, the correct answer is B as melanocytes are specifically responsible for producing melanin.

2. A table shows the average blood pressure readings for different age groups. How do you determine the highest average systolic pressure?

A. Find the largest number in the "systolic pressure" column.
B. Compare the means (averages) of each age group.
C. Add all systolic pressure values and divide by the total number of patients.
D. Subtract the lowest systolic pressure from the highest.

Correct answer: A

Rationale: Rationale: - To determine the highest average systolic pressure, you need to identify the highest individual systolic pressure reading in the dataset. - Option A instructs you to find the largest number in the "systolic pressure" column, which directly addresses the task of identifying the highest systolic pressure reading. - Comparing means (Option B) would not necessarily give you the highest individual systolic pressure reading, as averages can be influenced by the distribution of values within each age group. - Adding all systolic pressure values and dividing by the total number of patients (Option C) would give you the overall average systolic pressure, not the highest individual reading. - Subtracting the lowest systolic pressure from the highest (Option D) would give you the range of systolic pressures, not specifically the highest individual reading. Therefore, the correct approach to determine the highest average systolic pressure

3. The lymphatic system is primarily responsible for:

A. Transporting nutrients throughout the body
B. Removing excess fluids and waste products from tissues
C. Producing red blood cells
D. Regulating body temperature

Correct answer: B

Rationale: The correct answer is B: 'Removing excess fluids and waste products from tissues.' The lymphatic system plays a crucial role in maintaining fluid balance in the body by collecting excess interstitial fluid and returning it to the bloodstream. This system also helps in removing waste products, pathogens, and toxins from tissues, contributing to the body's immune response. Options A, C, and D are incorrect because transporting nutrients, producing red blood cells, and regulating body temperature are primarily the functions of other systems in the body such as the circulatory system, bone marrow, and the thermoregulatory system, respectively.

4. What happens to the internal energy of a system when it performs work on its surroundings?

A. It increases.
B. It decreases.
C. It remains the same.
D. Information insufficient

Correct answer: B

Rationale: When a system performs work on its surroundings, it loses internal energy in accordance with the first law of thermodynamics.

5. What is the scientific study of the relationships between organisms and their environment?

A. Zoology
B. Botany
C. Ecology
D. Genetics

Correct answer: C

Rationale: Rationale: A) Zoology is the scientific study of animals. B) Botany is the scientific study of plants. C) Ecology is the scientific study of the relationships between organisms and their environment, including the interactions between living organisms and their physical surroundings. D) Genetics is the scientific study of genes, heredity, and variation in living organisms, which is not directly related to the relationships between organisms and their environment.

6. What is the process of making copies of RNA from DNA called?

A. Replication
B. Transcription
C. Translation
D. DNA repair

Correct answer: B

Rationale: Rationale: Transcription is the process of making copies of RNA from DNA. During transcription, the enzyme RNA polymerase binds to a specific region of DNA and synthesizes a complementary RNA strand based on the DNA template. This process is essential for gene expression and protein synthesis in cells. Replication (option A) refers to the process of making copies of DNA, not RNA. Translation (option C) is the process of synthesizing proteins from mRNA, not making copies of RNA from DNA. DNA repair (option D) involves mechanisms that cells use to repair damaged DNA, not the process of making RNA copies from DNA.