In vertebrate animals, spermatogenesis and oogenesis differ in that
A) oogenesis begins at the onset of sexual maturity, whereas spermatogenesis begins during embryonic development.
B) oogenesis produces four haploid cells, whereas spermatogenesis produces only one functional spermatozoon.
C) cytokinesis is unequal in oogenesis, whereas it is equal in spermatogenesis.
D) oogenesis ends at menopause, whereas spermatogenesis is finished before birth.
E) spermatogenesis is not completed until after fertilization occurs, but oogenesis is completed by the time a girl is born.
Organization of the vertebrate nervous system.
Deserts differ across the world. (a) Acacia trees between a gravel plain and sand dunes in the Namib
The Xenopus frog tadpole is a small, simple vertebrate.
An Extinct Vertebrate and a Modern Relative
The skulls of living haplorhines differ from those of strepsirhines by having large brains, an enclo
Examples of transgenic animals