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TLS Online TPP Program

#Question id: 2896

Different modification states of the residue Lys-9 on the tail of histone H3 could be interpreted to have different meanings. One example of how a histone modification can apparently influence a second modification present nearby is illustrated by the Drosophila HP1 protein. Which of the following statement is correct regarding this kind of epigenetic regulation?

#Unit 2. Cellular Organization

  1. During metaphase, the HP1 protein binds in high concentration to the mitotic chromosomes, as they retain the essential “mark—namely, histone H3 methylation of lysine 9 (H3K9).

  2. The dissociation of HP1 by the Aurora B kinase seems to be required for the attachment of the mitotic spindles to the centrosomes and the subsequent separation of sister chromatids during cytokinesis.

  3. After the completion of mitosis, the phosphorylation of serine 10 is still retained because of Aurora B kinase activity, and HP1 dissociates from the chromosome to maintain the euchromatin state of chromosomes.

  4. Loss of HP1 binding is associated with phosphorylation of the neighboring serine residue at position 10 of H3 which is mediated by a cell cycle kinase called Aurora B that becomes active only after the M phase of the cell cycle.

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TLS Online TPP Program

#Question id: 3257

#Unit 11. Evolution and Behavior

Which of the following statements about evolution is NOT true?
TLS Online TPP Program

#Question id: 3258

#Unit 11. Evolution and Behavior

Which of the following incorrect about genetic drift
TLS Online TPP Program

#Question id: 3259

#Unit 11. Evolution and Behavior

Different type of evolution leads to group of taxon in following three manners

A- group of taxon whose member have descended from common ancestor

B- when two lineages convergently  evolve similar character states form  groups that are recognized by pheneticists

c. taxon that include most recent ancestor but not all of its descendent
TLS Online TPP Program

#Question id: 3260

#Unit 11. Evolution and Behavior

Consider a diploid population at Hardy-Weinberg equilibrium. For a locus with two alleles, the frequency of the A1A1 genotype is 0.04) The frequency of A2 allele is
TLS Online TPP Program

#Question id: 3261

#Unit 11. Evolution and Behavior

A parent population (P) is change into daughter populations (Q) which grow in habitats. After 1000 generations, the equilibrium frequency distribution of of the daughter populations is shown in the figure below. For reference, the vertical line represents the mean of the parent population. Which type of natural selection?
TLS Online TPP Program

#Question id: 3262

#Unit 11. Evolution and Behavior

In a population, the genotype frequencies are: f(A1A1)= 0.35; f(A1A2) = 0.30; f(A2A2) = 0.35; Which of the following statement is correct?