What are alveoli? A. Part of a red blood cell

B. Air sacs used during respiration

C. Tubes that connect the heart to the lungs

D. Carbon dioxide molecules

What does is mean if a population meets all five conditions

How does the atmosphere primarily replenish its supply of nitrogen?

List the two groups of seedless plants

Despite being farther away from the sun than Mercury, Venus has a much warmer temperatures. What accounts for Venus is temperature being higher than mercury's?

The role of enzymes in biological systems is to do which of the following? Bulid cell membranes, Slow down chemical reactions, building blocks of DNA and RNA, speed up chemical reactions

Can energy be transferred from animal to animal

The more stomata the more water loss?

Why does it take a long time to develop a new variety of tomato? A. Changes in traits happen gradually, over many generations. B. Many plants resist change. C. Tomatoes cannot acquire new traits. D. A species cannot change over time.

Select the one true statement. Vacuoles store nutrients, water, and waste in animal cells. Plant cells can have chloroplasts but do not have a cell wall.

Using water more effectively A. Protects the environment B. Causes the loss of natural pollution filters C. Increases with contamination D. All of the above