A zygote is

Correct Answer: C

Rationale: The correct answer is C: a diploid fertilized ovum. A zygote is formed when a sperm fertilizes an ovum, resulting in a diploid cell with a complete set of chromosomes. This marks the beginning of a new individual. A) Incorrect: An ovum is a haploid cell produced by the female reproductive system. B) Incorrect: A secondary oocyte is a haploid cell that has undergone meiosis II but has not been fertilized yet. D) Incorrect: A polar body is a haploid cell that is produced during oogenesis and eventually disintegrates.

Correct Answer: C

Rationale: The correct answer is C: Nullipara. Nullipara refers to a woman who has never given birth to a child. "Nulli-" means none or zero, and "-para" refers to giving birth. This term specifically indicates the absence of any childbirth experience, regardless of pregnancy history. A: Primipara would refer to a woman who has given birth to one child. B: Nulligravida would refer to a woman who has never been pregnant. D: Primigravida would refer to a woman who is pregnant for the first time. Therefore, C is the correct choice as it accurately describes a woman who has not experienced childbirth.

Correct Answer: C

Rationale: The correct answer is C, Herpes. Herpes is a viral infection caused by the herpes simplex virus, not a bacterial infection. Chlamydial (A), Gonorrhea (B), and Syphilis (D) are all bacterial infections caused by specific bacteria. Therefore, Herpes does not fit the category of bacterial infections, making it the correct choice.

Correct Answer: B

Rationale: The correct answer is B: Fossa. A fossa is a hollow cavity or depression within a bone. It serves as an attachment site for muscles, ligaments, or tendons. Sulcus (A) is a groove or furrow, not a hollow cavity in a bone. Fissure (C) is a narrow opening or cleft, not a hollow cavity. Sinus (D) is a cavity within a bone filled with air, not necessarily hollow. Therefore, the best choice for a hollow cavity within a bone is a fossa.

Correct Answer: C

Rationale: The correct answer is C: 11, 12 ribs. Floating ribs are ribs that do not have a direct attachment to the sternum. Ribs 11 and 12 are considered floating ribs because they do not attach to the sternum or cartilage of other ribs, only to the vertebrae in the back. Choices A and B are incorrect because ribs 1-10 are not considered floating ribs. Choice D is incorrect because ribs 11 and 12 are indeed the floating ribs of the thoracic cage.