Species that are critical to the functioning of an ecosystem

What is the main reason people moved to cities during the Gilded Age? A. to get jobs in factories and corporate headquarters. B. to enable their children to attend universities there. C. to discover and create new technologies. D.

What is a substrate? A. a molecule that changes stateB. a place where the reaction occursC. a place on the product where the enzyme fitsD. a reactant that is catalyzed by an enzyme

A human impact on the nitrogen cycle, such as fertilizer

What happens when sunlight transfers energy to the air closest to the ground?

If forests serve as important sinks for greenhouse gases, describe how past ice ages might have affected the concentration levels of carbon dioxide in the atmosphere.

Maria is testing the behavior of monkeys. First, she shows the monkey a rectangle. Then she shows the monkey a rectangle and a cylinder. If the monkey pushes aside the rectangle, Maria gives the monkey a food reward.

Why is the phloem in a leaf important to the roots of a plant? A. It provides the roots with carbohydrates. B. It provides the roots with nutrients from the soil. C. It transports water to the leaves from the roots. D.

A mutation causing an addition or a deletion of one base pair resulted in the production of a nonfunctional mutant protein. The sequences of the normal and mutant proteins are given below.

What job does each organelle do in a cell?

Which of the following statements is true of an object composed of a single cell? It could be considered living only if it has some of the other characteristics of life. It is a living thing. It is not a living thing. It could become a living thing.