Q22 of 30 Page 1

(i) Name the enzyme that catalyses the transcription of hnRNA.

(ii) Why does the hnRNA need to undergo changes? List the changes hnRNA undergoes and where in the cell such changes take place.


i) The enzyme which catalyses the transcription of hnRNA is the DNA independent RNA polymerase.

ii)hnRNA undergoes changes so as to convert non-functional hnRNA to functional mRNA.


The changes which take place are :


a) RNA Splicing: In this process the introns are removed from the RNA and exons are left and joined together via ligase.


b) Capping: In this process a 7-methyl guanosine triphosphate nucleotide is added to the 5’ end of the hnRNA.


c) Tailing: In this process the 3’ end is adenylated


More from this chapter

All 30 →
20

Branching descent and natural selection are the two key concepts of Darwinian Theory of Evolution. Explain each concept with the help of a suitable example.

 21

Scientists have succeeded in recovering healthy sugarcane plants from a diseased one.

(a) Name the part of the plant used as explant by the scientists.


(b) Describe the procedure the scientists followed to recover the healthy plants.


(c) Name the technology used for crop improvement.


 23

(i) Write the scientific names of the two species of filarial worms causing filariasis.

(ii) How do they affect the body of infected person(s)?


(iii) How does the disease spread?


 24

Name the genus to which baculoviruses belong. Describe their role in the integrated pest management programmes.