Unit 8: Biodiversity, Viruses (8.2)

Question 1

First person to isolate a virus

Answer 1

Wendell Stanley

Question 2

The virus Wendell Stanley isolated

Answer 2

The virus was Tobacco Mosaic Virus - TMV

Question 3

Viruses possess either a ______ or_________ strand of DNA or RNA. (This is how viruses are classified.)

Answer 3

double, single

Question 4

Viruses contain very small amounts of _____ or ______– most are 4 to 500 genes total.

Answer 4

DNA, RNA

Question 5

The 2 purposes of the Capsid (Viral Protein Coat)

Answer 5

1. Protection of the DNA or RNA strands inside.

2. Attachment of the virus to a host cell.

Question 6

The capsid is built from protein units called ___________. (means “capsid unit”)

Answer 6

capsomeres

Question 7

Some viruses can also have a ______ _________.

Answer 7

viral envelope

Question 8

This is a cloak derived from the previous host cell plasma membrane. (It is an example of mimicry. It looks like a normal cell, but it is actually like a Trojan horse. The danger is inside.)

Answer 8

Viral Envelope

Question 9

The _____/______ virus has a viral envelope derived from the T-helper white blood cells.

Answer 9

AIDS/HIV

Question 10

These are viruses that attack bacteria.

Answer 10

Bacteriophages (A.K.A. Phages)

Question 11

These are some of the largest and most complex viruses.

Answer 11

Bacteriophages

Question 12

Viruses are not ______ organisms. They cannot be _______. They can be broken apart using chemicals though.

Answer 12

living, killed

Question 13

Viruses must have a host cell in order to reproduce. (They are considered _______ _________ _______. As the name indicates, viruses must get inside the host cell in order to reproduce.)

Answer 13

Obligate Intracellular Parasites

Question 14

Viruses need to use the ____ cells ribosomes and enzymes to make new DNA or RNA strands and new capsomeres to form new viruses.

Answer 14

host

Question 15

Refers to what organisms a virus can attack. It is determined by recognition of certain glycoproteins or glycolipids on the host cell membrane.

Answer 15

Host Range

Question 16

These enzymes, found in bacteria, act as primitive defense against viruses. These enzymes cut up the viral genome and thus inactivate the genes from being transcribed. They are called restriction enzymes because they only cut at certain nucleotide sequences. In other words, they are restricted in where they can cut.

Answer 16

Restriction Enzymes

Question 17

a unique type of viruses. They use reverse transcriptase, an enzyme, to turn RNA into DNA. (It does transcription backwards. It turns “mRNA” into double stranded DNA, so that it can incorporate into the host DNA.

Answer 17

Retroviruses

Question 18

Examples of retroviruses (2)

Answer 18

Aids/Hiv and the common cold virus

Question 19

Major viruses (4)

Answer 19

HIV/AIDS, Ebola, Influenza, SARS

Question 20

Big Outbreak in one area

Answer 20

Epidemic

Question 21

Global Outbreak

Answer 21

Pandemic

Question 22

(Over 2,000 are known to exist.) (Big financial loss for farmers because of destroyed crops.)

Answer 22

Plant viruses

Question 23

(These are naked, infectious RNA molecules.) They attack plants only. (“oid” means “like”… they are “like” viruses as they are infectious.)

Answer 23

Viroids

Question 24

(These are infectious proteins) Mad Cow – Kruetzfeldt-Jacob Disease is one example. The destroy brain cells thus driving the cow “mad” until it dies. The human version is KJD above.

Answer 24

Prions