Hook formation and maintenance result from ethylene-induced asymmetric growth,  indicating that phytochrome is the photoreceptor involved in this process

a) Red light induces hook folding, and far-red light reverses the effect of red

b) close interaction between phytochrome and ethylene controls hook opening

c) Red light inhibits ethylene formation, promoting growth on the inner side, thereby causing the hook to open

Which of the following combination from the given statements is correct?

#Question id: 2916

#Unit 2. Cellular Organization

Which of the following statement is INCORRECT regarding the packaging of DNA into higher order chromatin structure?

#Question id: 2917

#Unit 2. Cellular Organization

With respect to the interconversion between open and condensed chromatin shown below: Which of the directions (i) or (ii) would you anticipate would be the consequence of the following types of chromatin modification?

#Question id: 2918

#Unit 2. Cellular Organization

Some DNA sequences in our cells have high frequencies of methylated cytosines (hypermethylation); some others have a low frequency of methylated cytosines (hypomethylation). Which of the two methylation states best describes the kind of sequences listed below? 

 I. Satellite DNA in pericentromeric heterochromatin

II. Promoters 

III. Dispersed transposon repeats

IV. CpG islands 

V. Enhancers

#Question id: 2919

#Unit 2. Cellular Organization

Topoisomerases play the essential role of unlinking the DNA molecules to allow them to separate into the two daughter cells for cell division. Which of the following statements regarding the mechanism of topoisomerases is INCORRECT?

#Question id: 2920

#Unit 2. Cellular Organization

Which of the following statements is INCORRECT with respect to the organization and content of the human genome?

#Question id: 4256

#Unit 2. Cellular Organization

With respect to CpG islands in our genomic DNA, which, if any, of the following descriptions do not apply?

1) frequently occurring (there are about 30,000 in the human genome).

2) long DNA sequences (typically from 10 kb to 100 kb in length).

3) low CG dinucleotide frequency.

4) frequently associated with transcriptional start sites.