39. NON-CODING RNA

Question 1

1. What happens to Non-Coding DNA?

Answer 1

• it is transcribed
• a large part of it is transcribed into Non Coding RNA
• ncRNA
• it is not translated
• part of it has genes for rRNA and tRNA

Question 2

2. What is the function of the non-coding RNA?

Answer 2

• it regulates the translation of mRNA
• it regulates Chromatin Configuration
• it regulates gene expression

Question 3

3. What are MicroRNAs?

Answer 3

• these are known as miRNAs
• they are single stranded RNA molecules
• they can bind to mRNA
• they have incomplete base pairing with many mRNA
  molecules
• they target many mRNA
• they degrade mRNA
• they mostly block the translation of mRNA

Question 4

4. What size are miRNAs?

Answer 4

• 20-25 bp

Question 5

5. What are Small Interfering mRNAs?

Answer 5

• these are known as siRNA
• they are double stranded RNA molecules
• they bind to the mRNA
• they have complete base pairing with the mRNA
  molecule
• they cause RNA interference (RNAi)
• this inhibits a gene expression coming from specific
  genes only
• they also degrade the mRNA

Question 6

6. How large are siRNAs?

Answer 6

• 20 to 25 bp

Question 7

7. What is Chromatin Modification?

Answer 7

• siRNAs induce heterochromatin formation
• they can block large regions of the chromosome
• this is done by inhibition of transcription
  and by the inhibition of gene expression

Question 8

8. What is Transcription regulation?

Answer 8

• the inhibition of transcription of specific genes