ATI RN
Human Reproductive System pdf NCERT Questions
Question 1 of 5
Which of the following is greater after birth than before birth?
Correct Answer: D
Rationale: Step-by-step rationale: 1. After birth, the foramen ovale closes, reducing flow (A) 2. Pressure in the right atrium decreases due to closing of fetal shunts (B) 3. Ductus arteriosus closes, reducing flow (C) 4. Aortic pressure increases as systemic circulation begins (D) Summary: A, B, and C decrease after birth due to closure of fetal shunts, while D increases as systemic circulation takes over, making it the correct choice.
Question 2 of 5
A scientist studying developmental physiology performs an experiment in which a substance is given to pregnant rats that give birth to pups that have XY chromosomes but female genital organs. What was the substance given to the rats?
Correct Answer: A
Rationale: The correct answer is A: An antibody that blocked the effect of human chorionic gonadotropin in the embryo and fetus. Human chorionic gonadotropin (hCG) is crucial for male sexual differentiation. Blocking its effects would lead to the development of female genital organs in pups with XY chromosomes. Estrogen-like compounds (B) and follicle-stimulating hormone (C) are not directly involved in male sexual differentiation. Testosterone (D) is responsible for male sexual development, so giving testosterone would not result in female genital organs in XY pups.
Question 3 of 5
A man who has been exposed to high levels of gamma radiation is sterile due to destruction of the germinal epithelium of the seminiferous tubules, although he has normal levels of testosterone. Which of the following would be found in this patient?
Correct Answer: A
Rationale: Step 1: High levels of gamma radiation cause destruction of germinal epithelium, leading to infertility. Step 2: Normal testosterone levels indicate intact Leydig cells, responsible for testosterone production. Step 3: Normal secretory pattern of gonadotropin-releasing hormone (GnRH) is expected as it regulates pituitary hormone secretion. Step 4: Inhibin is produced by Sertoli cells (part of germinal epithelium) and would be decreased due to destruction. Step 5: Follicle-stimulating hormone (FSH) levels would be elevated, not suppressed, due to lack of inhibin feedback. Step 6: Leydig cells are intact, so Leydig cells are not absent in this scenario.
Question 4 of 5
At what point in life does a female begin her monthly ovarian cycle?
Correct Answer: B
Rationale: The correct answer is B: At puberty. The monthly ovarian cycle, also known as the menstrual cycle, begins at puberty when a female's body matures and starts ovulating. This is typically around the age of 11-14. At birth (A), females already have all their eggs but do not start ovulating until puberty. Middle age (C) refers to the period around 40-65, which is not when the cycle begins. Menopause (D) is the cessation of the menstrual cycle, marking the end of reproductive years, typically around the age of 45-55.
Question 5 of 5
What excess cellular component do spermatids shed to become sperm during spermiogenesis?
Correct Answer: B
Rationale: During spermiogenesis, spermatids shed excess cytoplasm to become mature sperm. This process helps streamline the sperm structure for efficient motility and fertilization. DNA (choice A) is essential for sperm function and remains within the sperm. The flagellum (choice C) is actually a necessary structure for sperm motility. Mitochondria (choice D) play a crucial role in providing energy for sperm movement. Shedding excess cytoplasm ensures that the mature sperm is streamlined and optimized for its specific functions.