All the information necessary for growth,
development, and eventual reproduction of
sexually reproducing organisms is present in
(1) sperm cells, only
(2) egg cells, only
(3) zygotes
(4) either sperm cells or egg cells

All eukaryotic cells contain small bodies called

Parthenogenesis is a type of reproduction that does not require a mate. it’s rarely seen in birds and higher vertebrates. parthenogenesis involves the formation of a zygote. but this zygote is formed without fertilization. in parthenogenesis, in the absence of a male gamete, the ovum develops directly in the zygote.

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.