chapter 25 section 1 Flashcards Preview

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Flashcards in chapter 25 section 1 Deck (16):
1

what is a virus ?

a nonliving particle composed of a nucleic acid and a protein or lipoprotein coat

2

what is a capsid?

the protein coat that surrounds the nucleic acid in a virus

3

what is a retrovirus?

a virus that contains RNA and the enzyme reverse transcriptase

4

what is a viroid?

smallest known particles that are able to replicate.
consists of a short, single strand of RNA and has no capsid

5

what is a prion?

abnormal forms of protein that clump together inside a cell

6

the diameter of viruses range from about

20-250 nm (nanometers)

7

viruses can reproduce

only within host cells

8

the enzyme reverse transcriptase uses

RNA as a template to make DNA

9

the grouping of viruses is based partly on the

presence or absence of an envelope

10

a disease causing particle made of RNA without a capsid is called

a viroid

11

what did wendel stanley do

crystallize the tobacco mosaic virus

12

what did wendel stanleys work suggest about the nature of viruses

that viruses were chemicals rather than tiny cells

13

2 strucutres of cells but not viruses

nucleus
cytoplasm

14

2 activities of cells but not viruses

cells can reproduce without help
cells are living organisms

15

what is the function of the glycoprotein on the surface of enveloped viruses

the viruses use glycoprotein to attach to the surface of a host cell

16

viruses are mainly grouped according to their

shape and structure.