1. Which sexually transmitted infection (STI) can potentially cause infertility in both men and women if left untreated?

A. Human papillomavirus (HPV)
B. Chlamydia
C. Gonorrhea
D. Syphilis

Correct answer: D

Rationale: The correct answer is D: Syphilis. Syphilis is a sexually transmitted infection that can potentially cause infertility in both men and women if left untreated. In men, untreated syphilis can lead to damage to the testicles and epididymis, affecting sperm production. In women, syphilis can result in pelvic inflammatory disease (PID) which can lead to scarring and blockages in the fallopian tubes, causing infertility. While other STIs like chlamydia and gonorrhea can also lead to infertility if left untreated, syphilis is particularly known for its severe impact on reproductive health in both genders.

2. How does the potential energy of an object change when it is compressed?

A. Potential energy decreases
B. Potential energy increases
C. Potential energy remains constant
D. Potential energy becomes zero

Correct answer: b

Rationale: When an object is compressed, it stores potential energy due to its altered position or configuration.

3. What is the primary function of DNA polymerase?

A. Packaging DNA
B. Replicating DNA
C. Transcribing DNA
D. Translating mRNA

Correct answer: B

Rationale: Rationale: DNA polymerase is an enzyme responsible for synthesizing new DNA strands during DNA replication. It adds nucleotides to the growing DNA strand based on the template provided by the existing DNA strand. This process ensures that genetic information is accurately copied and passed on to daughter cells during cell division. Packaging DNA (option A) refers to the coiling and organization of DNA into chromatin, a process involving histones and other proteins. Transcribing DNA (option C) involves the synthesis of RNA from a DNA template, a process carried out by RNA polymerase. Translating mRNA (option D) refers to the process of protein synthesis where the information encoded in mRNA is used to assemble amino acids into a polypeptide chain.

4. During gas exchange in the alveoli, what happens to oxygen?

A. Oxygen is released from the bloodstream into the alveoli.
B. Oxygen is absorbed from the alveoli into the bloodstream.
C. Oxygen is converted into carbon dioxide.
D. Oxygen is stored in the alveoli for later use.

Correct answer: B

Rationale: During gas exchange in the alveoli, oxygen is absorbed from the alveoli into the bloodstream. In the alveoli, oxygen diffuses across the thin walls of the alveoli and into the surrounding capillaries where it binds to hemoglobin in red blood cells. This oxygen-rich blood is then transported to the body's tissues for cellular respiration. Therefore, option B is correct as it accurately describes the direction of oxygen movement during the process of gas exchange in the lungs.

5. Which of the following is the main organ responsible for producing antibodies?

A. Thymus gland
B. Spleen
C. Bone marrow
D. Lymph nodes

Correct answer: C

Rationale: Rationale: Antibodies are proteins produced by specialized white blood cells called B lymphocytes (B cells). These B cells mature in the bone marrow, where they undergo a process of differentiation and maturation to become plasma cells that secrete antibodies. The bone marrow is the primary site for the production of B cells and antibodies in the immune system. The thymus gland is responsible for the maturation of T lymphocytes (T cells), not antibody production. The spleen and lymph nodes play roles in filtering and trapping pathogens but are not the main organs responsible for producing antibodies.

6. The major site for nutrient absorption in the digestive system is the:

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: C

Rationale: The correct answer is C: Small intestine. The small intestine is the major site for nutrient absorption in the digestive system. It is where most of the digestion and absorption of nutrients from food takes place. The small intestine has villi and microvilli that increase its surface area, allowing for efficient absorption of nutrients like sugars, amino acids, and fatty acids into the bloodstream. The mouth is primarily responsible for mechanical digestion through chewing, while the stomach's main function is to break down food with enzymes and acids. The large intestine mainly absorbs water and electrolytes, with minimal nutrient absorption.