Lecture 39 Viruses

Question 1

Viruses

Answer 1

infectious non-cellular agents

Question 2

What do viruses no have?

Answer 2

nucleus, organelles, or cytoplasm

Question 3

True or False: viruses contain only RNA

Answer 3

False! viruses can contain either DNA or RNA (but NEVER both)

Question 4

Can viruses replicated outside of the host cell?

Answer 4

No!

Question 5

Do viruses have metabolic processes such as digestion?

Answer 5

No!

Question 6

Nucleic Acid

Answer 6

either DNA or RNA (single or double stranded); huge variation in genome size; circular and linear

Question 7

Capside

Answer 7

protein coat that encloses and protect nucleic acid core

Question 8

What are capsids composed of?

Answer 8

capsomeres (they give proteins their distinctive shape)

Question 9

Viron

Answer 9

complete virus particle = nucleic acid + capsid + envelope

Question 10

Naked virus

Answer 10

have nucleic acid core and capsid (nucleocapsid)

Question 11

Enveloped virus

Answer 11

have nucleocapsid and envelope

Question 12

Envelope

Answer 12

phospholipid bilayer with proteins that can be used for attachment to host cell; derived from host cell so it is difficult for immune system to detect

Question 13

What are the spike-like projections of an enveloped virus used for?

Answer 13

used to bind to/attach to receptors on the host cell surface

Question 14

What are the spike-like projections of an enveloped virus made of?

Answer 14

proteins and/or carbohydrates

Question 15

What are some examples of larger viruses?

Answer 15

smallpox and measels

Question 16

What are som examples of smaller viruses?

Answer 16

yellow fever and polio

Question 17

Morphological types of viruses

Answer 17

1) polyhedral
2) helical
3) complex

Question 18

Polyhedral shaped virus example

Answer 18

Herpes

Question 19

Helical shaped virus example

Answer 19

Ebola, rabies

Question 20

How are complex viruses special?

Answer 20

can recognize specific hosts through their specifically defined tail fibers

Question 21

How can complex viruses be used by us?

Answer 21

can be helpful against antibiotic resistant bacteria

Question 22

Components of a complex virus

Answer 22

• capsid head
• sheath
• tail fiber
• pin
• baseplate

Question 23

What do family names of viruses end in?

Answer 23

-viridae

Question 24

What do genus names of viruses end in?

Answer 24

-virus

Question 25

Viral species

Answer 25

a group of viruses sharing the same genetic information and ecological niche

Question 26

What is used to name viral species?

Answer 26

common names

Question 27

What is used to name viral subspecies?

Answer 27

numbers

Question 28

What characteristics are viruses classified by?

Answer 28

size, shape, nucleic acid composition, presence/absence of an envelope, host range