Biodiversity lesson 3: viruses

Question 1

what are viruses?

Answer 1

non-cellular particle made up of genetic material and protein that can invade living cells

Question 2

what are retro viruses?

Answer 2

a special class of viruses that contain RNA as their genetic material that contains reverse transcriptase

Question 3

what does reverse transcriptase do?

Answer 3

allows the virus to reverse transcribe viral RNA to DNA that is inserted to host genome

Question 4

are viruses alive?

2 valid reasons

Answer 4

NO=
1. because all viruses depend on live hosts to exist, it is unlikely that they evovled first
OR
2. more likely that viruses developed from genetic material of living things and have continued to evolve since then

Question 5

when does lysogenic cycle begin?

Answer 5

after an infection the viral DNA inserts itself into hosts of DNA

Question 6

what is the product of the combination of viral dna and host dna in lysogenic cycle?

Answer 6

prophage

Question 7

what can prophage cause

(3 things can happeeeen)

Answer 7

1. block entry of other virsus to host cells
2. may insert useful DNA
3. may become acive and seperate from the host cell to create replicase of itself

Question 8

are viruses alive?

( 2 non-valid reasons)

Answer 8

1. viruses are considerd parasites that pray on living organisims, ezpecially to survive
   ** OR**
2. viruses are not considered living cells however they are clearly part of the system of life on earth

first reason is bad because parasites are alive

Question 9

what is a capsid?

Answer 9

the protective layer that surrounds the cone of nucleic acid (DNA or RNA) contained in all viruses.