With respect to nucleosome, which of the following statements is incorrect ?
1. | Nucleosome contains 120 bp of DNA helix. |
2. | Nucleosomes are seen as 'beads' on string' under Electron Microscope. |
3. | DNA is wrapped around positively charged histone octamer to form nucleosome. |
4. | Nucleosome is the repeating unit of chromatin. |
One of the strands of double stranded DNA has base composition as follows: 15% A, 15% T, 40%G and 30%C. What will be the percentage of these bases in the complementary strand ?
1. 15% A, 15% T, 30% G , 40% C
2. 15% A, 30% T, 40% G , 15% C
3. 15% A, 15% T, 40% G , 30% C
4. 15% A, 40% T, 15% G , 30% C
What would be the proportions of light and hybrid density DNA molecule, respectively if Meselson and Stahl's experiment was continued for 60 minutes?
1. 50%, 50%
2. 25%, 75%
3. 75%, 25%
4. 100%, 0%
Assertion (A): | Expressed sequence tags (ESTS) which was used in human genome project it identify all the genes that are expressed as DNA. |
Reason (R): | Complete DNA sequence is decoded. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
1. | If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only). |
2. | If one stop codon, such as UGA, is found to have a different effect on translation than another stop codon, such as UAA. |
3. | If prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide. |
4. | If several codons are found to translate to the same amino acid, such as serine. |
1. | The number of repeats varies widely from person to person or animal to animal. |
2. | The sequence of DNA that is repeated varies, significantly, from individual to individual. |
3. | The sequence variation is acted upon differently by natural selection in different environments. |
4. | Every racial and ethnic group has inherited different short tandem repeats. |