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

Correct Answer: B

Rationale: Chlamydia is the correct answer because if left untreated, it can lead to serious complications such as pelvic inflammatory disease (PID) in women and epididymitis in men, both of which can cause infertility. Chlamydia is a common sexually transmitted infection that often presents with no symptoms, making it important for individuals to get tested regularly, especially if they are sexually active. It is crucial to detect and treat Chlamydia early to prevent long-term consequences such as infertility. Human papillomavirus (HPV) can lead to genital warts and certain types of cancer but is not typically associated with infertility. Gonorrhea and syphilis can cause serious health problems if untreated, but infertility is more commonly associated with Chlamydia.

Correct Answer: C

Rationale: Chronic stress can weaken the immune system by increasing the production of stress hormones like cortisol, which can suppress the immune response. This suppression can make individuals more susceptible to infections and illnesses. Conversely, regular exercise, a balanced diet, and adequate sleep actually support a healthy immune system and help strengthen it. Choices A, B, and D are incorrect as they are factors that generally contribute positively to the immune system. Regular exercise, a balanced diet, and adequate sleep are crucial for maintaining overall health and boosting the immune system rather than weakening it.

Correct Answer: A

Rationale: Epithelial tissue is the correct answer as it aligns with the description provided in the question. Epithelial tissue is characterized by tightly packed cells with minimal extracellular matrix, which allows it to form protective barriers on the body's surface and line internal organs, providing structural support and protection. Connective tissue, while important for support and connection between tissues and organs, does not fit the description in the question of being tightly packed with minimal extracellular matrix. Muscle tissue is responsible for movement, and nervous tissue transmits signals throughout the body, neither of which are primarily involved in providing structural support and protection as described. Therefore, based on the characteristics described in the question, epithelial tissue best fits the description of tissue that provides structural support and protection.

Correct Answer: B

Rationale: Sebaceous glands are responsible for secreting an oily substance called sebum, not sweat, cerumen, or mucus. Sebum plays a vital role in lubricating and waterproofing the skin and hair, preventing them from drying out. Sweat glands produce sweat to regulate body temperature. Cerumen is the medical term for earwax, produced by ceruminous glands in the ear canal, while mucus is a slimy substance that protects and lubricates body tissues. Therefore, the correct answer is B: Sebum, as it is the oily substance secreted by sebaceous glands.

Correct Answer: A

Rationale: Calcium is crucial for bone strength as it is a major mineral stored in bones and teeth. It plays a vital role in maintaining bone density and strength, making it essential for overall bone health. Calcium is essential for various physiological functions, including muscle contraction, nerve transmission, and blood clotting. Inadequate calcium intake can lead to conditions like osteoporosis, where bones become weak and brittle. Iron (Choice B) is important for transporting oxygen in the blood, but it is not stored in bones and does not play a significant role in bone strength. Magnesium (Choice C) is essential for bone health, but it is not primarily stored in bones and teeth. Potassium (Choice D) is crucial for various physiological functions, such as fluid balance and muscle function, but it is not a major mineral stored in bones and teeth for bone strength.