MOD 8

Question 1

What methods are used to detect miRNA expression changes?

Answer 1

miRNA microarray, Next Gen Sequencing, RT-qPCR

Question 2

How is gain of function studied in miRNA research?

Answer 2

Using miRNA mimics or expression vectors

Question 3

How is loss of function studied in miRNA research?

Answer 3

Using synthesized inhibitors or gene knockouts

Question 4

What is the goal of functional miRNA studies?

Answer 4

To confirm gene targets by measuring expression changes

Question 5

What is the genome type of most plant viruses?

Answer 5

ssRNA

Question 6

What are examples of plant viruses with different genome types?

Answer 6

Badnavirus: dsDNA, Geminivirus: ssDNA, Potyvirus: +ssRNA

Question 7

What are the common virus shapes?

Answer 7

Helical and icosahedral

Question 8

What are the five methods of virus transmission in plants?

Answer 8

Vegetative propagation, seed, pollen, contact, vectors

Question 9

What defines persistent propagative insect vectors?

Answer 9

Virus replicates in the insect and is transmitted both vertically and horizontally

Question 10

Name common insect vectors of plant viruses.

Answer 10

Aphids, whiteflies, leafhoppers, thrips, mealybugs

Question 11

What are virus satellites?

Answer 11

RNA molecules dependent on helper virus for replication

Question 12

What are characteristics of virus satellites?

Answer 12

No sequence homology, may or may not encode a coat protein, use rolling circle replication

Question 13

What are viroids?

Answer 13

Circular, single-stranded RNAs that do not encode proteins

Question 14

How do viroids replicate?

Answer 14

Autonomously via rolling circle mechanisms

Question 15

What are the two viroid families and their characteristics?

Answer 15

Pospiviroidae: nucleus replication, Avsunviroidae: chloroplast replication and autocatalytic cleavage

Question 16

How do viruses move between plant cells?

Answer 16

Through plasmodesmata assisted by movement proteins

Question 17

What is the triple gene block (TGB)?

Answer 17

Three overlapping genes, including RNA helicase TGB1, that enable virus movement

Question 18

What is the function of the 30K movement protein superfamily?

Answer 18

Increase size exclusion limit of plasmodesmata, bind RNA, form tubular structures

Question 19

What pathway allows systemic virus movement in plants?

Answer 19

Via vascular tissue, primarily phloem

Question 20

What protein is required for systemic virus movement?

Answer 20

Capsid protein

Question 21

What is ‘spillover’ in plant virus ecology?

Answer 21

Virus moves from natural to new host

Question 22

What are three levels of plant virus control?

Answer 22

Elimination, prevent transmission, protect plants

Question 23

Name two examples of protection strategies for plants.

Answer 23

Mild strain protection, genetic engineering

Question 24

What defines innate immunity in plants?

Answer 24

No detectable virus replication

Question 25

What defines tolerance in plants?

Answer 25

Virus replication without visible symptoms

Question 26

What defines resistance in plants?

Answer 26

Reduced severity or hypersensitive response

Question 27

What are the two phases of plant immune response?

Answer 27

Cellular level (extreme resistance), tissue level (hypersensitivity)

Question 28

What is VIGS?

Answer 28

Virus-induced gene silencing via mild strain cross-protection

Question 29

What is HIGS?

Answer 29

Host-induced gene silencing via transgenic disruption of viral genes

Question 30

What triggers RNA interference in plants?

Answer 30

Double-stranded RNA leading to mRNA degradation

Question 31

Why is RNA-based biopesticide advantageous?

Answer 31

Highly specific, biocompatible, effective, non-toxic, and leaves no residue

Question 32

What challenge limits transgenic crop use?

Answer 32

Cost, time, and lack of transformation protocols