The cell membrane protects the cell, separates the internal and external environments, and does not allow any material to enter or exit the cell.

Explain the process by which the land, atmosphere, and oceans of earth formed

What can you logically infer from the following facts: (There is a greenhouse effect (Carbon dioxide is a greenhouse gas (People have increased the concentration of carbon dioxide in the atmosphere dramatically since industrial times A) The Earth is

Five types of food for a healthy diet

Energy must be transformed in ecosystems because?

What type of mutation causes cystic fibrosis?

Which is a nonliving thing because it is not able to reproduce? a. bacteria b. cactus c. snake d. dust

Give examples of a property that depends on both heritage and environment

What is a reaction to tissue damage caused by injury or infection?

Where do the three steps of cellular respiration occur?

The smallest and most exclusive grouping