The principle stating that the oldest rocks occur on the bottom of an undisturbed rock sequence is known as a. superposition. b. original juxtaposition. c. relative age dating. d. original parallelism.

The following image is of a diatom. it lives in water and gets food from photosynthesis. it is encased in a hard shell made of something similar to glass or sand . a diatom is a(n) because it has a) multi-celled organism; specialized parts. b) vertebrate; a skeleton. c) insect; an exoskeleton. d) single-called organism; only one cell.

Why is excretion necessary to maintain homeostasis?

How many copies of genes do gametes have?