Scientific theories, such as the theory of evolution, must be

A - neither testable nor observable

B - testable and observable

C - observable

D - testable

Sperm cells have a very specialized structure, including a flagellum and very little cytoplasm. explain how the structure of a sperm cell contributes to its function.

From the initial stage to the final stage of ecological succesion what kind of change is occuing

What is meant when we say that organisms evolve?

How does the wind transport sediment particles

A pneumothorax is a possible complication of COPD. Symptoms will depend on the suddenness of the attack and the size of the air leak. The most common, immediate symptom that should be assessed is:

This is an organ in the digestive system which transports waste out of the body and absorbs water from the waste before it leaves the body.

Which two actioms happens when bonds in ATP moecules are broken

Explain how inherited cancer alleles can lead to a predisposition to certain cancers.

Which organelle is responsible for poviding a barrier?

Which of the following are outputs of the process of photosynthesis? A. Energy from food and oxygen B. Energy from the sun, carbon dioxide, and water C. Nutrients from food and oxygen D. Food and oxygen