Kaplan Nursing Entrance Practice Exam

What is a key characteristic of oogenesis?

1. Continuous production of mature eggs

2. Production of eggs only with Y chromosomes

3. Production of ova that donate mitochondria to embryos

4. Four mature eggs are produced each cycle

The correct answer is: Production of ova that donate mitochondria to embryos

A key characteristic of oogenesis is the production of ova that donate mitochondria to embryos. During the development of the female gamete, known as an oocyte, the oocyte is filled with cytoplasmic components including mitochondria. When fertilization occurs, the mitochondria from the ova are passed on to the embryo, while the sperm's mitochondria are typically not inherited. This maternal contribution to the embryo is crucial for early development, as mitochondria are responsible for energy production through cellular respiration. In contrast to this, the other options inaccurately represent aspects of oogenesis. Continuous production of mature eggs is not characteristic because unlike spermatogenesis, which occurs continuously, oogenesis is a cyclical process that begins before birth and resumes at puberty in a monthly cycle, resulting in the release of a single mature egg rather than continuous production. The production of eggs only with Y chromosomes is incorrect as ova always carry an X chromosome; it is the sperm that determines the sex of the offspring by contributing either an X or a Y chromosome. Lastly, while oogenesis can produce up to four oocytes from a single process, only one of these typically matures into a functional egg during each reproductive cycle, making the notion that four mature eggs are produced each