Nokea
Choose the statement that is NOT TRUE:
- A. Fragmentation is followed by regeneration.
- B. The offspring from asexual reproduction is genetically identical.
- C. The embryo of ovoviviparous gets nourishment from the egg yolk.
- D. Crossing-over occurs between sister chromatids of homologous chromosomes.
Correct Answer: D
Rationale: The correct answer is D because crossing-over occurs between non-sister chromatids of homologous chromosomes during meiosis, not between sister chromatids. This genetic exchange results in genetic variation. Fragmentation is followed by regeneration in some organisms, asexual reproduction produces genetically identical offspring, and ovoviviparous embryos do get nourishment from the egg yolk.
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The cell produced by fertilization is called
- A. gamete
- B. embryo
- C. fetus
- D. zygote
Correct Answer: D
Rationale: The correct answer is D: zygote. After fertilization, the sperm and egg unite to form a zygote, which is the initial cell of a new organism with a full set of chromosomes. A gamete (A) is a reproductive cell before fertilization, an embryo (B) is the early stage of development after the zygote, and a fetus (C) is the later stage of development in the womb. Therefore, the zygote is the correct term for the cell produced by fertilization.
During a physical examination of the male reproductive system, how does the nurse assist the examiner to gather clues about the density of scrotal tissue?
- A. Through a digital rectal examination
- B. By externally inspecting the size of the scrotum
- C. Through transillumination
- D. Through a scrotal radiography
Correct Answer: C
Rationale: Transillumination helps assess the density and presence of fluid in the scrotum.
A fertilized egg, which represents the first cell of a new individual, is called a(n) ________.
- A. blastocyst
- B. zygote
- C. fetus
- D. embryo
Correct Answer: B
Rationale: The correct answer is B: zygote. A zygote is formed when a sperm cell fertilizes an egg cell, marking the beginning of a new individual's development. It is the first cell of the new organism with a full set of chromosomes.
A: Blastocyst is a later stage of development after the zygote has undergone several cell divisions.
C: Fetus refers to the later stages of development when the embryo has developed recognizable features.
D: Embryo is the stage after the zygote when the cells start to differentiate into different tissues and organs.
In order for milk to flow from the nipple of the mother into the mouth of the nursing infant, which of the following must occur?
- A. Myoepithelial cells must relax
- B. Prolactin levels must fall
- C. Oxytocin secretion from the posterior pituitary must take place
- D. The baby’s mouth must develop a strong negative pressure over the nipple
Correct Answer: C
Rationale: The correct answer is C because oxytocin is responsible for stimulating the contraction of myoepithelial cells around the alveoli in the mammary glands, causing milk ejection. This process is known as the let-down reflex. In contrast, choice A (myoepithelial cells must relax) is incorrect because they need to contract to push milk out. Choice B (prolactin levels must fall) is incorrect because prolactin is responsible for milk production, not milk ejection. Choice D (the baby's mouth must develop a strong negative pressure over the nipple) is incorrect because it is the mother's hormone release, not the baby's action, that causes milk flow.
The straight tubules in the testis lead into the
- A. Efferent ducts
- B. Afferent ducts
- C. Rete testis
- D. Ductus epididymis
Correct Answer: D
Rationale: The correct answer is D: Ductus epididymis. The straight tubules in the testis lead into the ductus epididymis because the sperm produced in the testis pass through the straight tubules and enter the epididymis for maturation and storage. This is a crucial step in the sperm development process before they are ready for ejaculation.
Rationale:
- A: Efferent ducts are incorrect because they connect the rete testis to the epididymis and are responsible for transporting sperm from the testis.
- B: Afferent ducts are incorrect as they carry sperm from the rete testis to the epididymis.
- C: Rete testis is incorrect as it is a network of tubules where the straight tubules converge and connect to the efferent ducts, not directly to the epididymis.