About how many major mass extinctions have there been in the earth's history

The humerus is the: select one: a. bone in the upper arm. b. bone in the upper leg. c. smaller of the two bones in the lower leg. d. larger of the two bones in the lower arm.

What is the dominant gas in the atmosphere that forms clouds is?

All organisms need energy to function witch cell organell provides this energy

In this food web, what is represented by the chains of arrows from the grass to the fox?

What is the gastrointestinal system? What does it do?

Which statement is an example of absolute age? 1) Dinosaurs lived a long time ago 2) Trilobites lives before dinosaurs 3) Teachers are old 4) Dinosaurs went extinct 65.5 million years ago

Identify the structure in the cell that will produce atp from the starch building blocks

True or false: plant cell cytokinesis is different from animal cell cytokinesis because the contractile filaments found in plant cells are structures composed of carbohydrates and the cleavage furrow in animal cells is composed of contractile

When you get a minor cut platelets in your blood stick to the wound and cause?

Why are phospholipids ideal for making up the selectively permeable membrane?