1. What type of molecule forms the cell membrane and controls what enters and exits the cell?

A. Proteins
B. Carbohydrates
C. Lipids
D. Nucleic acids

Correct answer: C

Rationale: The correct answer is C: Lipids. The cell membrane is primarily composed of a double layer of lipids called phospholipids. These phospholipids have a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails, which arrange themselves to form a barrier that controls the passage of substances in and out of the cell. While proteins are also present in the cell membrane and play important roles in transport and cell signaling, lipids are the main structural component responsible for the selective permeability of the membrane. Carbohydrates are typically found on the outer surface of the membrane and are involved in cell recognition and communication. Nucleic acids are not a major component of the cell membrane; they are primarily responsible for storing and transmitting genetic information within the cell.

2. Which of the following is an example of aseptic technique?

A. Washing hands with soap and water before surgery
B. Coughing into your elbow
C. Sharing a stethoscope without cleaning
D. Leaving a wound dressing exposed

Correct answer: A

Rationale: Rationale: Aseptic technique refers to practices that help prevent the introduction of harmful microorganisms into a sterile environment. Washing hands with soap and water before surgery is an essential component of aseptic technique as it helps reduce the number of microorganisms on the hands, decreasing the risk of introducing pathogens into the surgical site. Coughing into your elbow is a good hygiene practice to prevent the spread of respiratory infections but is not specifically related to aseptic technique. Sharing a stethoscope without cleaning can introduce microorganisms from one patient to another, compromising aseptic conditions. Leaving a wound dressing exposed can lead to contamination and infection, which is contrary to aseptic technique.

3. Energy for most cellular processes is produced in the:

A. Nucleus
B. Cytoplasm
C. Mitochondria
D. Ribosomes

Correct answer: C

Rationale: The correct answer is C: 'Mitochondria.' The mitochondria are known as the powerhouse of the cell, where the process of cellular respiration takes place to produce energy in the form of ATP. The nucleus (option A) houses the cell's genetic material but is not directly involved in energy production. The cytoplasm (option B) is a jelly-like substance that surrounds organelles but is not the primary site of energy production. Ribosomes (option D) are involved in protein synthesis, not energy production. Therefore, the mitochondria play a crucial role in generating energy for most cellular processes.

4. The science of classifying organisms into different groups based on their evolutionary relationships is called:

A. Taxonomy
B. Microbiology
C. Genetics
D. Epidemiology

Correct answer: A

Rationale: Rationale: Taxonomy is the science of classifying organisms into different groups based on their evolutionary relationships. It involves identifying, naming, and categorizing living organisms according to their similarities and differences. Microbiology (option B) is the study of microorganisms, Genetics (option C) is the study of genes and heredity, and Epidemiology (option D) is the study of the distribution and determinants of health-related states or events in populations.

5. What is the protective fluid that surrounds the brain and spinal cord?

A. Blood
B. Cerebrospinal fluid
C. Myelin sheath
D. Insulin

Correct answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. This fluid acts as a cushion for the brain and spinal cord, providing protection from impacts. Blood is essential for transporting nutrients and oxygen, but it does not directly surround or protect these vital nervous system structures. Myelin sheath is a fatty substance that insulates nerve fibers, not the fluid surrounding the nervous system. Insulin is a hormone involved in regulating blood sugar levels and is not related to protecting the brain and spinal cord.

6. Negative feedback mechanisms are crucial in the endocrine system to:

A. Increase hormone production continuously
B. Maintain hormone levels within a specific range
C. Cause a constant release of hormones
D. Disrupt communication between glands

Correct answer: B

Rationale: The correct answer is B: 'Maintain hormone levels within a specific range.' Negative feedback mechanisms in the endocrine system are essential for regulating hormone levels. These mechanisms work to counteract any deviations from the set point, ensuring that hormone levels remain balanced and within the optimal range for proper physiological function. Continuous hormone production (A) or constant release of hormones (C) would lead to imbalances and potential harm to the body. Disrupting communication between glands (D) would hinder the coordination necessary for maintaining homeostasis. Therefore, option B is the best choice as it highlights the critical role of negative feedback in keeping hormone levels stable and regulated.