Who came up with the cell theory and the three cell theory?

Wich idea states the earth took thousands of years to form

The coloration of Adelie penguins is very simple compared to some of their more colorful cousins. Their coloration could also be compared to that of some predatory fish (for example, the great white shark).

The secretion of parathyroid hormone is controlled primarily by the

What do scientists usually do when a scientific problem first arises?

the circulaatory and respitortory system wor together to provide cells with oxygen and nutrients and remove waste products such as cabon dioxide. when u need more oxygen, how does the circulatory system respond?

Which organisms are prokaryotes a. Archaea b. Fungi c. Protist d. Plants

A population of lizards that originally had no predators lived on a small isolated island. Predators of the lizards were accidently introduced to the island from a visiting ship.

If there are 50 kcal of energy in the tertiary consumer trophic level, how many kcal would you expect to find in the primary consumer level

The plasma membranes of some plant cells use transport proteins to move protons out of the cell against their concentration gradient (from areas of low proton concentration to areas of high proton concentration). this is an example of:

What is algae? and where is come from?