Suppose that there are 500 units of energy available at the producer level of the energy pyramid. Approximately how many units of energy are available to the first level consumer?

Which of these is the major difference between asexual and sexual reproduction in sea stars?

Which factors can have the greatest effect on the health of a river system? A. type of soil and salinity B. nitrate levels and turbidity C. human consumption and pH D. natural disasters and tidal changes

What was the name of the kingdom that all bacteria were once classified into

The white blood cells primarily responsible for adaptive immunity are

Each enzyme produced by the body is specific-meaning it is only able to catalyze a reaction with a certain substrate. What causes an enzyme to be specific? The enzyme's surface folds are complementary to the substrate's surface folds.

What characteristic of Charales would enable them to survive a dry spell? sperm with flagella phragmoplasts sporopollenin chlorophyll a

Many Head Start programs have a community aide who A. tutors at-risk children in the home. B. gives families the money they need to survive. C. connects families to community resources they need. D. represents families at family/teacher conferences.

Stranded on an island, you have two sources of water to drink: salty ocean water and contaminated fresh water. explain your choice of drinking water and indicate why your selection is the best choice.

How are a hypothesis a prediction and an experiment related

Two species of garter snakes live in the same geographic area. One lives mainly in water and the other mainly on land; therefore, they rarely encounter each other and do not interbreed. What type of isolation is this?