1. The process by which a cell divides to produce two daughter cells is called:

A. Mitosis
B. Meiosis
C. Differentiation
D. Transformation

Correct answer: A

Rationale: The correct answer is A: "Mitosis." Mitosis is the process of cell division in which a cell duplicates its chromosomes and divides into two identical daughter cells. This is a crucial mechanism for growth, repair, and maintenance of multicellular organisms. Meiosis (option B) is a different type of cell division that produces gametes with half the number of chromosomes. Differentiation (option C) refers to the process by which cells become specialized for specific functions. Transformation (option D) is a term used in molecular biology to describe the uptake of foreign DNA by a cell. In this question, the specific process of cell division leading to the production of two daughter cells aligns with mitosis.

2. During photosynthesis, plants capture sunlight and convert water and carbon dioxide into glucose and oxygen. This is an example of a:

A. Decomposition reaction
B. Combustion reaction
C. Synthesis reaction
D. Double displacement reaction

Correct answer: C

Rationale: The correct answer is C: Synthesis reaction. During photosynthesis, plants combine water and carbon dioxide using sunlight to produce glucose and oxygen. In a synthesis reaction, two or more substances combine to form a more complex product. In this case, glucose and oxygen are synthesized from simpler molecules. A decomposition reaction involves breaking down a compound into simpler substances, which is not the case in photosynthesis. Combustion reactions involve the rapid reaction of a fuel with oxygen to produce heat and light, which is also not the process occurring in photosynthesis. Double displacement reactions involve the exchange of ions between two compounds to form new compounds, which is not the mechanism of photosynthesis. Therefore, the process described in the question aligns with a synthesis reaction.

3. A medication must be taken twice daily, 12 hours apart. If the first dose is at 8:00 AM, what is the most convenient time for the second dose to avoid disrupting sleep?

A. 4:00 PM
B. 6:00 PM
C. 8:00 PM
D. 10:00 PM

Correct answer: B

Rationale: Rationale: To take the medication 12 hours apart from the first dose at 8:00 AM, the second dose should be taken at 8:00 PM. However, to avoid disrupting sleep, it is recommended to take the second dose a bit earlier. Taking the second dose at 6:00 PM ensures that the medication is still being taken 12 hours apart while allowing for a buffer before bedtime to avoid any potential disruptions to sleep.

4. What is the role of surfactant in the respiratory system?

A. To trap dust particles
B. To increase lung compliance
C. To produce mucus
D. To generate oxygen during respiration

Correct answer: B

Rationale: The correct answer is B: 'To increase lung compliance.' Surfactant is a substance produced by the alveolar cells in the lungs that reduces surface tension within the alveoli. This helps to prevent the alveoli from collapsing, making it easier for the lungs to expand and contract during breathing. This action increases lung compliance, which is the ease with which the lungs can be inflated. Trapping dust particles (A) is the role of mucus and cilia in the respiratory system. Surfactant does not produce mucus (C) but rather acts to reduce surface tension. Generating oxygen (D) is the function of the respiratory system as a whole through the process of respiration, and surfactant does not play a direct role in this process.

5. What potential consequences can chromosomal nondisjunction have on offspring?

A. Down syndrome, caused by an extra copy of chromosome 21.
B. Turner syndrome, characterized by the absence of one X chromosome in females.
C. Klinefelter syndrome, featuring one or more extra X chromosomes in males.
D. All of the above.

Correct answer: D

Rationale: Rationale: - Chromosomal nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal number of chromosomes in the resulting cells. - Down syndrome is caused by an extra copy of chromosome 21, resulting from nondisjunction during meiosis. Individuals with Down syndrome have three copies of chromosome 21 instead of the usual two. - Turner syndrome is characterized by the absence of one X chromosome in females, leading to a variety of physical and developmental features. - Klinefelter syndrome features one or more extra X chromosomes in males, typically resulting in infertility and other physical characteristics. Therefore, chromosomal nondisjunction can lead to various genetic disorders such as Down syndrome, Turner syndrome, and Klinefelter syndrome, making option D the correct answer.

6. The body's first line of defense against pathogens includes:

A. Phagocytes
B. Antibodies
C. Memory B cells
D. T lymphocytes

Correct answer: A

Rationale: Rationale: Phagocytes are a type of white blood cell that plays a crucial role in the body's innate immune response, which is the first line of defense against pathogens. Phagocytes engulf and digest foreign particles, such as bacteria and viruses, helping to prevent infection and disease. Antibodies (option B) are produced by B cells and are part of the adaptive immune response, not the first line of defense. Memory B cells (option C) are also part of the adaptive immune response and are involved in mounting a faster and stronger response upon re-exposure to a pathogen. T lymphocytes (option D) are another type of white blood cell involved in the adaptive immune response, specifically in cell-mediated immunity.