Micro-evolution is the term used for changes in allele frequencies that occur over time.

A) It gives rise to changes in the gene pool, which results in few changes in the same species

B) It occur above species level

C) New addition, deletion in the genetic structure, resulting in the formation of new species

D) It changes occurs over short time scales

Which of the following combinations is correct?

#Question id: 2886

#Unit 2. Cellular Organization

Match the following sites of modifications on histones given in Column I with their effect on transcription given in Column II.

COLUMN I                                               COLUMN II

1) Methylation of H3K36 in transcribed region               a) Activation

2) Ubiquitinylation of H2BK120 in mammals                b) Repression

3) Phosphorylation of H2AT120                                    c) Elongation

4) Hypoacetylated Lysine

5) Acetylation of H4K8

#Question id: 2887

#Unit 2. Cellular Organization

Which of the following reasons has led to the evolutionary selection of an extra methyl group in DNA?

#Question id: 2888

#Unit 2. Cellular Organization

Repressive complexes have been discovered that are composed of multiple repressing proteins bound to RNAs many kilobases in length that do not contain long open reading frames and are consequently called long noncoding RNAs or lncRNAs. Which of the following statements is correct regarding the regulation of these lncRNAs?

#Question id: 2889

#Unit 2. Cellular Organization

The edges of each base pair are exposed in the major and minor grooves, creating a pattern of hydrogen-bond donors and acceptors and of hydrophobic groups (allowing for Vander Waals interactions) that identifies the base pair. The edge of an C : G base pair displays the following chemical groups in the following order in the major groove:

#Question id: 2890

#Unit 2. Cellular Organization

Match individual variant histones i) to iv) to one or more of the possible functions listed in a) to g).

Variant histones              Functions 

i) CENP-A                         a) DNA replication

ii) H2A.X                           b) As a barrier to stop heterochromatin spreading

iii) H2A.Z                          c) DNA repair

iv) H3.3                             d) Transcriptional activation

                                          e) Kinetochore assembly 

                                           f) Recombination

                                          g) Genome maintenance

#Question id: 2891

#Unit 2. Cellular Organization

Which of the following statements regarding the Structural Maintenance Chromosomal proteins is correct?

A. The cohesins, along with a third protein, kleisin, are thought to form a ring around the replicated chromosomes.

B. Condensin binding causes the DNA to become underwound, in contrast to the overwinding induced by the binding of nucleosomes.

C. Cohesins are made up of pairs of Smc1 and Smc3 proteins, and condensins consist of Smc2-Smc4 pairs.

D. The primary structure of SMC proteins consists of three distinct domains.