A2.3 Viruses HL

Question 1

Viruses

Answer 1

Small infectious particles, ranging from 20 nm to 500 nm in size

Question 2

Capsid

Answer 2

Protein sheath surrounding and protecting a virus’s genetic material.

Question 3

Genetic Material of Viruses

Answer 3

Either DNA or RNA, can be single- or double-stranded.

Question 4

Single-stranded RNA Viruses

Answer 4

Examples include HIV, influenza, coronaviruses.

Question 5

Double-stranded DNA Viruses

Answer 5

Include bacteriophage lambda, variola virus, herpesviruses.

Question 6

Enveloped Viruses

Answer 6

Viruses surrounded by a lipid and protein membrane, like HIV and influenza.

Question 7

Non-enveloped Viruses

Answer 7

Viruses without an envelope, more stable, e.g., adenovirus.

Question 8

Viral Genome Size

Answer 8

Ranges from as few as four genes to thousands of genes

Question 9

Lytic Cycle

Answer 9

Viral replication process causing host cell destruction

Question 10

Lysogenic Cycle

Answer 10

Dormant viral state, integrating its genome into the host cell genome

Question 11

Obligate Intracellular Parasites

Answer 11

Viruses rely on host cells for replication and survival

Question 12

Convergent Evolution in Viruses

Answer 12

Unrelated viruses develop similar traits independently

Question 13

Retroviruses

Answer 13

RNA viruses with high mutation rates, e.g., HIV.

Question 14

Viral Evolution

Answer 14

Fast adaptation and change over time, especially in RNA viruses

Question 15

Recombination in Viruses

Answer 15

Exchange of genetic material between viruses

Question 16

Host Cell Dependency

Answer 16

Viruses depend on host cells for energy, nutrients, and replication machinery

Question 17

Viral Structure Diversity

Answer 17

Wide variety in shapes and genome types

Question 18

Viral Origins

Answer 18

Possible origins include ancient genetic material, viroids, and transposons

Question 19

Viral Reproduction

Answer 19

Cannot occur independently; relies on host cell machinery

Question 20

Viral Mutation Rates

Answer 20

RNA viruses mutate faster due to error-prone replication enzymes