Bat shaped bone that form part of the base of the skull is called as

Correct Answer: B

Rationale: The correct answer is B: Sphenoid bone. The sphenoid bone is bat-shaped and forms part of the base of the skull. It is located in the middle of the skull, helping to connect the cranial bones. The other choices, A: Ethmoid bone, C: Parietal bone, and D: Occipital bone, do not match the description of a bat-shaped bone at the base of the skull. The ethmoid bone is located between the eyes, the parietal bone forms the top and sides of the skull, and the occipital bone forms the back and base of the skull. Therefore, B is the correct answer based on the specific description given in the question.

Correct Answer: B

Rationale: The correct answer is B: Elbow. The radius, ulna, and humerus form the elbow joint. The ulna and humerus articulate at the trochlear notch, forming the hinge joint, while the radius articulates with the humerus at the capitulum, allowing for rotation. This combination of movements allows for flexion and extension of the forearm. The other choices, knee (A), ankle (C), and shoulder (D), involve different bones and joints in the body that do not include the radius, ulna, and humerus.

Correct Answer: C

Rationale: The correct answer is C because the external female reproductive organs typically include the vaginal opening, the labia majora, and the clitoris. The vaginal opening is where sperm enters and a baby exits during childbirth. The labia majora are the outer folds of skin that protect the vaginal and urethral openings. The clitoris is a highly sensitive sexual organ that plays a key role in sexual pleasure. Option A is incorrect because it includes the mons pubis, which is not considered an external reproductive organ. Option B is incorrect because it includes the hymen, which is a thin membrane that may partially cover the vaginal opening but is not a consistent external organ. Option D is incorrect because it includes the ovaries, which are internal organs responsible for producing eggs, not external reproductive organs.

Correct Answer: D

Rationale: The correct answer is D: primary spermatocyte. Primary spermatocytes are the cells in the seminiferous tubules that progress through the first meiotic division. During this division, primary spermatocytes undergo DNA replication and then divide into two secondary spermatocytes. These secondary spermatocytes will then undergo the second meiotic division to produce haploid spermatids. Explanation for why other choices are incorrect: A: Sertoli cells are supporting cells in the seminiferous tubules but do not undergo meiotic divisions. B: Spermatogonia are the undifferentiated germ cells that give rise to primary spermatocytes but do not progress through meiotic divisions. C: Spermatids are the haploid cells produced after the two meiotic divisions, so they do not progress through the first meiotic division. In summary, primary spermatocytes are the cells that go through the first meiotic division in the seminiferous tubules

Correct Answer: A

Rationale: The correct answer is A: seminiferous tubules. Sperm production starts in the seminiferous tubules of the testes through a process called spermatogenesis, involving the division and maturation of germ cells. The other choices, B: epididymis, C: vas deferens, and D: ejaculatory duct, are incorrect as they are not sites of sperm production but rather play roles in sperm storage, transport, and ejaculation, respectively. The seminiferous tubules are specifically designed for sperm production, making them the correct choice in this context.