TLS Online TPP Program

#Question id: 7254


Following statements regarding to the micromeres specification and regulatory input  in sea urchin embryo. Which of the following statement is correct?

#Unit 5. Developmental Biology
  1. OTX is a general transcription factor, and β-catenin from the maternal cytoplasm is concentrated at the vegetal pole of the egg. These transcriptional regulators are inherited by the macromeres and activate the Pmar1 gene.
  2. Pmar1 encodes a repressor of HesC, which in turn encodes activator of several genes involved in micromere specification.
  3. In the veg2 cells, Pmar1 is not activated and the HesC gene product shuts down the non-skeletogenic genes.
  4. As soon as the micromeres form, maternal β-catenin and Otx activate the Blimp1 gene, whose product activates the Wnt8 gene. Wnt8 protein is then received by the same micromeres that made it (i.e., autocrine regulation), activating the micromeres’ own genes for β-catenin.
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TLS Online TPP Program

#Question id: 3395

#Unit 9. Evolution & Diversity of Life Forms

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 9. Evolution & Diversity of Life Forms

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?

TLS Online TPP Program

#Question id: 3397

#Unit 9. Evolution & Diversity of Life Forms

In a large natural population of Mimulus guttatus, one leaf was sampled from each of a large number of plants. The leaves were crushed and subjected to gel electrophoresis. The gel was then stained for a specific enzyme, X. Six different banding patterns were observed, as shown in the accompanying diagram.

 Which one of the following conclusions is most appropriate based on the above observations?

A) There are three alleles of one locus and that the individuals with two bands are heterozygotes.

B) There are two alleles of one locus and that the individuals with two bands are heterozygotes

C) Population is present as hardy-Weinberg equilibrium

D) Population is not present as hardy-Weinberg equilibrium

TLS Online TPP Program

#Question id: 3398

#Unit 9. Evolution & Diversity of Life Forms

Genetic drift in a small population for multiple generations can significantly affect the composition of a population’s gene pool. Following some observation are given for reason of Genetic drift?

A) Small populations are threatened by a loss of genetic variability. This loss may be caused by inbreeding, genetic drift, and limited mating.

B) Sampling error can arise is through the founder effect, which is due to the limited matting within population

C) Genetic drift arises is through a genetic bottleneck, which develops when a population undergoes a drastic reduction in population size.

D) Variance in allele frequency due to genetic drift will be maximal when one allele is very rare and the population size is small.

Which of the above observation are true?

TLS Online TPP Program

#Question id: 3399

#Unit 9. Evolution & Diversity of Life Forms

What is probability of neutral mutation to be lost from the population size 100 and Probability of being homozygote in given population size 10 respectively?

TLS Online TPP Program

#Question id: 3400

#Unit 9. Evolution & Diversity of Life Forms

Which of the following influence effective population size?

a. Sex ratio

b. variation between individuals in reproductive success

c. Fluctuations in population size

d. Small breeding group