To avoid being degraded by nuclear exonucleases, nascent transcripts, pre-mRNA-processing intermediates, and mature mRNAs in the nucleus must have their ends protected. Which of the following mechanism are present in the cell to protect mRNA from degradation?

I. The 5′ cap is protected because it is bound by a heterodimeric nuclear cap-binding complex (CBC), which protects it from 5′ exonucleases and also functions in export of the mRNA to the cytoplasm.

II. 5’-5’ phosphodiester bond in the cap of mRNA plays crucial role in protection

III. The 3′ end of a nascent transcript lies within the RNA polymerase and is thus inaccessible to exonucleases 

#Question id: 11410

#Unit 10. Ecological Principles

Biodiversity hot spots, those areas with the greatest number of endemic species. Which of the following criteria to qualify as a hot spot region?

A. It must contain at least 1,500 species of vascular plants as endemics

B. It must have lost at least 70% of its original habitat

C. It must contain at least 500 species of bird species

D- It must contain high numbers of species

#Question id: 11411

#Unit 10. Ecological Principles

Vulnerability to extinction can be linked to species following characteristics. Which of the following statement are correct?

 A. Rare species are more prone to extinction than common ones.

 B. Species that are capable of migrating between fragments of habitat, such as between mainland areas and islands, may be more resistant to extinction

 C. Organisms that are specialists are more likely to go extinct

 D. Species with naturally long life spans may be more likely to become extinct

#Question id: 11412

#Unit 10. Ecological Principles

following is criteria to qualify Hot spot.

a) r-selected species

b) High numbers of endemic species

c) Many different types of habitats

d) k- selected species

#Question id: 11413

#Unit 10. Ecological Principles

Which of the following is NOT an attribute of a species that makes it vulnerable to extinction?

#Question id: 11414

#Unit 10. Ecological Principles

Which of the following combination of species feature that affecting a species’ sensitivity to extinction?

#Question id: 11415

#Unit 10. Ecological Principles

Below is a list of various bird groups, with their typical age at maturity (in years). Which of these would you expect to have the greatest annual survival?