In spermatogenesis, the spermatogonia produce(s) ____ sperm and in oogenesis, the oogonia produce(s) ____ ovum(s).
4; 1
4; 2
2:4
4; 4
1; 4
The Correct Answer is A
A. 4; 1: During spermatogenesis, a single primary spermatocyte undergoes two meiotic divisions to produce four functional, haploid spermatozoa. In contrast, oogenesis involves asymmetrical cytokinesis, where one primary oocyte yields only one functional secondary oocyte and three non-functional polar bodies. This allows the single ovum to retain the cytoplasm necessary for early embryonic life.
B. 4; 2: Oogenesis does not result in two functional ova under normal physiological conditions. While two polar bodies may be visible at different stages, only one cell matures into the gamete capable of being fertilized. Producing two functional eggs would be the result of a double ovulation event rather than the standard meiotic process.
C. 2:4: This ratio is the reverse of biological reality. Males produce significantly more gametes per meiotic event than females to ensure a higher probability of fertilization. Females prioritize the quality and nutrient content of a single cell over the quantity of gametes produced. This ensures the zygote has an adequate supply of organelles.
D. 4; 4: If oogenesis produced four functional ova, human multiple births would be the standard rather than the exception. The energy cost of producing four nutrient-rich eggs is too high for the female reproductive strategy. Asymmetrical division is a specific evolutionary adaptation to ensure the survival of a single fertilized zygote.
E. 1; 4: This choice suggests males produce fewer gametes than females per meiotic cycle, which is incorrect. A single spermatogonium eventually leads to the production of four spermatids through the process of meiosis. Oogenesis is the pathway that results in a single functional gamete due to the formation of polar bodies.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
A. decreases surface area of the scrotum, increases its thickness, and prevents heat loss: The dartos is a layer of smooth muscle within the superficial fascia of the scrotum. When it contracts in response to cold temperatures, it causes the scrotal skin to wrinkle and tighten. This reduction in surface area and the resulting thickening of the wall minimizes radiant heat loss to the environment.
B. allows scrotum and testes to hang lower from the body: This occurs when the dartos and cremaster muscles relax, typically in response to warm temperatures. Moving the testes away from the pelvic cavity promotes cooling by increasing the distance from core body heat. Relaxation is a heat-dissipating mechanism rather than a result of muscle contraction.
C. elevates the scrotum: While the dartos contributes to the tightening of the sac, the primary muscle responsible for the vertical elevation of the testes toward the inguinal canal is the skeletal cremaster muscle. The dartos primarily affects the texture and surface area of the skin itself. Elevation is a coordinated effort but is specifically the cremasteric reflex.
D. increases surface area of the scrotum, decreases its thickness, and allows heat loss: This description characterizes the physiological state of the scrotum during heat exposure. When the dartos muscle is flaccid, the skin becomes thin and smooth, maximizing the area available for cooling. This is the opposite effect of the contraction described in the question stem.
Correct Answer is B
Explanation
A. collecting duct: While the collecting duct plays a critical role in final water reabsorption and urine concentration, it receives drainage from multiple nephrons. It is not considered the basic unit because it is shared among many functional units. Its activity is primarily regulated by antidiuretic hormone.
B. nephron: This is the microscopic structural and functional unit responsible for filtering blood and forming urine. Each kidney contains approximately 1 million nephrons, each consisting of a renal corpuscle and a renal tubule. It performs all primary renal functions including filtration, reabsorption, and secretion.
C. capsular space: This is the physical gap between the visceral and parietal layers of the glomerular capsule. It serves as the initial reservoir for glomerular filtrate before it enters the proximal tubule. It is merely a compartment within a larger structure rather than a complete functional unit.
D. nephron loop: Also known as the loop of Henle, this is a specific U-shaped segment of the renal tubule. It is essential for establishing the medullary osmotic gradient via the countercurrent multiplier system. It represents only one part of the entire nephron's complex tubular system.
E. glomerular capsule: This epithelial structure captures the fluid filtered from the glomerular capillaries. While it is a vital part of the renal corpuscle, it cannot function independently to produce urine without the associated glomerulus and tubules. It is a sub-component of the nephron unit.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.