TLS Online TPP Program

#Question id: 2912


HOTAIR is a lncRNA whose gene is found in the Hox C cluster in humans, but it acts by regulating expression of the Hox D genes on another chromosome (in trans) by recruiting to that locus Polycomb Repressive Complex 2. Which of the following statements is/are correct regarding this regulation?

#Unit 2. Cellular Organization
  1. PRC2 adds trimethyl groups to lysine 27 of histone H3, a mark (H3K27me3) associated with repressed gene expression.

  2. HOTAIR also recruits a second complex that removes histone modifications typically associated with active genes.

  3. Deleting the PRC2-binding domain of HOTAIR destroys its regulatory functions in both development and cancer.

  4. All of the above

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TLS Online TPP Program

#Question id: 3391

#Unit 11. Evolution and Behavior

Which of the following statements is an example of genetic drift?

a. Allele g for fat production increases in a small population because birds with more body fat have higher survivorship in a harsh winter.

b. Random mutation increases the frequency of allele A in one population but not in another.

c. Allele R reaches a frequency of 1.0 because individuals with genotype rr are sterile.

d. Allele m is lost when a virus kills all but a few individuals and just by chance none of the survivors possess allele m

TLS Online TPP Program

#Question id: 3392

#Unit 11. Evolution and Behavior

Color blindness is X linked recessive disorder. X+ chromosome carry a normal allele but Xc chromosome carries defective allele. When frequency of colorblindness female (0.10), colorblind male (0.30) and heterozygous female (0.20). Random matting population, what will be frequency of carrier female?

TLS Online TPP Program

#Question id: 3393

#Unit 11. Evolution and Behavior

Natural Selection can maintain a polymorphism when

a. heterozygote is fitter than the homozygote

b. Fitnesses of genotypes are negatively frequency dependent.

c. Fitnesses of genotypes are positive frequency dependent.

d. One homozygote is fitter than the heterozygote

TLS Online TPP Program

#Question id: 3394

#Unit 11. Evolution and Behavior

All genetic drift arises from sampling error.  There are several different ways in which sampling error can arise as a following

a. Reduced population size      b. Founder effect

c. Genetic bottleneck                d. Differ in sex ratio

Which of the following above way cause sampling error in succeed generation?

TLS Online TPP Program

#Question id: 3395

#Unit 11. Evolution and Behavior

The Hardy-Weinberg principle states that allele frequencies in a population will remain constant over generations if certain assumptions are met.

A. Random mating

B. Sexual selection

C. Migration

D. Large population size

E. Reproductive isolated from other population

F. Linkage of many genes

Which of the above factors will cause changes in allele frequencies overgenerations?

TLS Online TPP Program

#Question id: 3396

#Unit 11. Evolution and Behavior

The Galapagos finches were an important clue to Darwin's thinking about the origin of species. These finches are believed to have descended from a single ancestral species that colonized the Galapagos archipelago, America, over a short period of time. The Galapagos finches differ in their beak shape and size. Different species feed on seeds that vary in size and hardness. Which of the following is the most likely explanation for these patterns?