Nokea
Birth control pills containing combinations of synthetic estrogen and progesterone compounds given for the first 21 days of the menstrual cycle are effective in preventing pregnancy. What is the explanation for their efficacy?
- A. Prevention of the preovulatory surge of luteinizing hormone secretion from the pituitary gland
- B. Prevention of development of the ovarian follicles
- C. Suppressing function of the corpus luteum soon after it forms
- D. Prevention of normal development of the endometrium
Correct Answer: A
Rationale: The correct answer is A. Birth control pills containing estrogen and progesterone prevent the preovulatory surge of luteinizing hormone (LH) secretion from the pituitary gland. This leads to the inhibition of ovulation, preventing the release of an egg from the ovary. Without ovulation, fertilization cannot occur, effectively preventing pregnancy.
Choice B is incorrect because birth control pills do not prevent the development of ovarian follicles; they prevent ovulation. Choice C is incorrect because suppressing the function of the corpus luteum is not the primary mechanism of action of birth control pills. Choice D is incorrect because birth control pills do not prevent the normal development of the endometrium; they primarily prevent ovulation.
You may also like to solve these questions
The patient is unable to tolerate a bimanual pelvic examination due to pain in ovaries and fallopian tubes. Which disorder does the nurse suspect?
- A. Tertiary syphilis
- B. Genital herpes
- C. Human papillomavirus (HPV) infection
- D. Pelvic inflammatory disease
Correct Answer: D
Rationale: The correct answer is D: Pelvic inflammatory disease (PID). PID is characterized by inflammation and infection of the female reproductive organs, including ovaries and fallopian tubes, leading to pain during bimanual pelvic examination. This is due to the inflammatory response in the pelvic area. Tertiary syphilis (A), genital herpes (B), and HPV infection (C) do not typically present with acute pelvic pain during examination. Syphilis affects multiple organ systems, herpes presents with genital lesions, and HPV usually does not cause acute pelvic pain. Therefore, PID is the most likely diagnosis based on the symptoms described.
If a cell has 46 chromosomes at the beginning of mitosis, determine the number of chromatids at
- B. 23 chromatids
- C. 46 chromatids
- D. 92 chromatids
Correct Answer: D
Rationale: The correct answer is D: 92 chromatids. In mitosis, each chromosome consists of two sister chromatids. Since the cell begins with 46 chromosomes, there are a total of 92 chromatids present. This is because each chromosome duplicates during the S phase of interphase, resulting in two identical sister chromatids held together by a centromere. Therefore, the total number of chromatids in the cell at the beginning of mitosis is twice the number of chromosomes. Choices A, B, and C are incorrect because they do not account for the duplication of chromatids that occurs during the cell cycle.
Structurally, the ovary displays:
- A. on the outside, an elastic tissue;
- B. on the surface, the glandular parenchyma;
- C. the cortical area, which contains ovarian follicles;
- D. the medullar area, which contains blood vessels;
Correct Answer: C
Rationale: Step 1: The ovary is a complex organ with distinct internal structures.
Step 2: The ovarian cortex houses ovarian follicles, which are crucial for reproductive functions.
Step 3: Ovarian follicles contain oocytes and support cells for oocyte development.
Step 4: Therefore, choice C is correct as it accurately describes the structural aspect of the ovary.
Summary: Choices A, B, and D are incorrect as they do not accurately describe the structural components of the ovary. Choice A talks about elastic tissue, choice B mentions glandular parenchyma, and choice D refers to blood vessels, none of which are specific to the structural arrangement of the ovary.
Sperm are formed in tightly coiled tubes called seminiferous tubules that are found within each ________.
- A. spermatic cord
- B. testis
- C. ductus deferens
- D. epididymis
Correct Answer: B
Rationale: The correct answer is B: testis. The seminiferous tubules are located within the testes, where sperm are produced through the process of spermatogenesis. The spermatic cord (A) contains blood vessels, nerves, and the vas deferens but not the seminiferous tubules. The ductus deferens (C) is a tube that carries sperm from the epididymis to the urethra, not where sperm are formed. The epididymis (D) is where sperm mature and are stored but not where they are initially formed. Therefore, the testis is the only choice where the seminiferous tubules are located for sperm production.
Upon fertilization, an oocyte completes its second meiotic division and produces ________.
- A. the corona radiata and a polar body
- B. the morula and blastocyst
- C. the ovum and another polar body
- D. the primary oocyte and secondary oocyte
Correct Answer: C
Rationale: Rationale: Upon fertilization, an oocyte completes meiosis II, resulting in the formation of the ovum and another polar body. The ovum contains the majority of the cytoplasm and organelles needed for fertilization and embryonic development, while the polar body is a small non-functional cell. This process ensures proper distribution of genetic material and cytoplasm.
Incorrect Choices:
A: The corona radiata and a polar body are structures associated with the ovulated oocyte, not the result of fertilization.
B: The morula and blastocyst are early embryonic stages that form after several cell divisions following fertilization, not products of oocyte meiosis.
D: The primary oocyte and secondary oocyte are stages of oocyte development before fertilization and are not produced after fertilization.