Lesson 4.8: Viruses in Plants, Viroids, Prions

Question 1

Viral infections on plants commonly spread on the _______

Answer 1

mouth of insect-eating plants (pitcher plants)

Question 2

Plants do not have an active immune system instead it undergo

while some may degrade

Answer 2

plant cells undergo apoptosis or programmed cell death when infected (preventing cancer)

viral mRNA

Question 3

What are Viroids?

Answer 3

infectious small and circular RNA molecules,

Question 4

Size of viroids and compare it to the size of a typical virus

Answer 4

240-600 nucleotides
which is one tenth of the typical virus

Question 5

Virus do not also encode proteins but they use host __________to ____

Function n

Answer 5

RNA polymerase to replicate
synthesizes RNA molecules from a DNA

Question 6

EXAMPLE OF VIROIDS

Answer 6

potato spindle virus

Question 7

what are prions

Answer 7

Infectious protein molecules

Question 8

what is TSEs

Answer 8

Transmissible Spongiform Encephalopathies (TSEs)
-degenerative brain diseases caused by prions

Question 9

Prions are responsible for _____ and some cases of ____- in humans

how are they transmitted?

Answer 9

mad cow disease

Creutzfeldt-Jakob Disease (Bovine Spongiform Encephalopathy)

By eating infected cow brain

Question 10

Which helped scientists to determine that evolutionary tree of these related viruses?

Some strains of HIV

Answer 10

Amino acid sequences

Group M, N, and O.