1) Which organisms accomplish most of the work of converting atmospheric nitrogen into a form usable to green plants?

A) bacteria and archaea

B) viruses

C) protists

D) fungi

2) The main decomposers on Earth are the:

A) viruses and protists.

B) plants and animals.

C) bacteria and fungi.

D) plants and fungi.

3) The material in the core of HIV (AIDS virus) is:

A) protein.

B) xarbohydrate.

C) DNA.

D) RNA.

4) The viral capsid is:

A) a fatty membrane surrounding the virus.

B) the genetic material at the core.

C) a protein coat around the genetic material.

D) the viral offspring that rupture the cell and escape.

5) Which of the following is the best description of a virus?

A) A virus is the smallest living thing.

B) A virus is a life-form that can reproduce inside cells or independently.

C) A virus is a tiny spore-producing cell.

D) A virus is a noncellular, replicating entity.

6) The process by which viruses can exchange genetic sequences to come up with a “new” virus such as H1N1 is:

A) recombination.

B) reassortment.

C) independent assortment.

D) conjugation.

7) The life cycle of viruses involves:

A) production of new virus particles on the outside of a cell.

B) reproducing on the surface of a cell.

C) filling the host cell with viral particles.

D) attaching viral DNA to the surface of a cell.

8) Which phrase most accurately describes the genome of most viruses?

A) surprisingly complex, with tens of thousands of genes

B) surprisingly complex, with around 1 million genes

C) the same as most bacteria, with hundreds of genes

D) relatively simple, with around a dozen genes or fewer

9) The human immunodeficiency virus targets:

A) lymph nodes.

B) all white blood cells.

C) helper T cells.

D) bone marrow cells.

10) A major difference between bacteria and eukaryotes is that bacteria have:

A) a rod-shaped nucleus.

B) no membrane-bound organelles.

C) faster mitosis as their method of sexual reproduction.

D) no ribosomes.