Explain why even though only one sperm fertilizes an ovum, over 360 million are released during ejaculation.
What will be an ideal response?
During ejaculation, about 360 million, and as many as 500 million, sperm are released, bathed in a protective fluid called semen. After entering the female's vagina, the sperm's tail propels it through the cervix into the uterus and onward toward the ovum. Sperm must travel for about 6 hours to reach the fallopian tube where an ovum may-or may not-be present. The journey is difficult: Some sperm get tangled up with other sperm, some travel up the wrong fallopian tube, others do not swim vigorously enough to reach the ovum. On average, about 300 sperm reach the ovum, if one is present. Those that travel up the fallopian tube can live up to 6 days, able to fertilize a yet unreleased ovum. The ovum, however, remains viable for about only a day after being released into the fallopian tube.
You might also like to view...
The process of locating and returning information to consciousness is referred to as
a. retrieval. c. retrospective memory. b. subconscious transfer. d. maintenance rehearsal.
Unlike other designs, single-subject designs:
a. do not average the individual's data with the data of other subjects. b. use random sampling. c. use random assignment. d. are not concerned with internal or external validity.
Aesthetic needs include the need
a. to be competent and recognized. b. for harmony, order, and beauty. c. for curiosity and exploration. d. to love and be loved. e. to understand the world.
Which disorder is often accompanied by "free-floating" anxiety?
a) panic b) acrophobia c) generalized anxiety disorder d) obsessive-compulsive disorder