The question refers to the following table, which compares the percent sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (for example, Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A.

Which of these four gene parts should allow the construction of the most accurate phylogenetic tree, assuming that this is the only part of the gene that has acted as a reliable molecular clock?

#Question id: 2849

#Unit 2. Cellular Organization

Methylation of lysines 4, 36, or 79 of histone H3 typically is associated……… of the genes, whereas methylation of lysines 9 or 27 of the same histone frequently is associated with …..

#Question id: 2850

#Unit 2. Cellular Organization

CCA-adding enzymes add a specific sequence without a template because

#Question id: 2851

#Unit 2. Cellular Organization

There is a growing body of evidence that acetylation of histone N-termini in specific chromosomal regions contributes to gene control by regulating the binding of histones to DNA and regulation of the folding state of chromatin. The extent of histone acetylation is correlated with the relative resistance of chromatin DNA to digestion by nucleases. Which combination of histone acetylation state and DNAse 1 resistance is characteristic of actively transcribed regions of chromatin?

#Question id: 2852

#Unit 2. Cellular Organization

The chromosomal karyotypes of two species of small deer, the Reeves muntjac and the Indian muntjac, are strikingly different despite the fact that the two genomes contain about the same amount of DNA. However, within a species, there are properties of chromosomes that are the same, i.e. species-specific. Select the answer that contains all of these species-specific properties of chromosomes at metaphase

#Question id: 2853

#Unit 2. Cellular Organization

Not all bacteria need to maintain their DNA in a negatively supercoiled state. Bacteria that prefer to grow at very high temperatures must expend energy. Which of the following observation found to be true?

A. Bacteria don’t need to expend energy to prevent their DNA from unwinding due to thermal denaturation

B. These bacterial organisms have a different topoisomerase called reverse gyrase

C. Reverse gyrase decrease the linking number of relaxed DNA in the presence of ATP

#Question id: 2854

#Unit 2. Cellular Organization

Negatively charged phosphate groups in the DNA backbone must be neutralized in order for folding of DNA to occur. In bacterial DNA, this charge neutralization is carried out by small positively charged molecules called polyamines. What proteins carry out this same function in eukaryotic cells?