Describe the outer covering of a reptile's egg.

Are the earth's ocean floor and continents the same age geologically? why or why not?

Explain what a zygote is. use the terms egg cell, sperm cell, and fertilization in your explanation.

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes