Which type of organism is responsible for performing the majority of nitrogen fixation ... ?

A. Humans

B. Aquatic organisms

C. Plants

D. Bacteria

What feature of alveoli adapts them to efficient gas exchange? A. They have muscles which pump air in and out regularly. B. Their membranes are more permeable to gases than water. C. A constant blood supply flows through them. D.

Where is the moon located, relative to earth and sun, when is it new? what about venus?

Explain the different preparations of cocaine and how they are used.

A gene exists as two alleles in a population of freely mating individuals. if 40% of the population carries the recessive allele (a for the gene, what percentage of the population has the homozygous recessive aa genotype?

Why are decomposers important? They break down dead and decaying organic material. They return nutrients and elements to a usable form in the environment. They consume the most energy of all the trophic levels. Both A & B are correct.

Mt. Aconcagu is the highest peak of which range

Members of Porifera are diploblastic. Which statement clarifies this? A. They are unsegmented. B. They have a true body cavity. C. They have two germ layers.

In what part of the cell does glycolysis take place

Geological evidence indicates that two landmasses, separated by a deep ocean channel, have been moving apart since 45 million years ago. You are studying a group of organisms that has widespread populations on both of the landmasses.

These are organisms produced with externally introduced genes