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TLS Online TPP Program

#Question id: 15297

 Which of the following statement is correct regarding mammalian cleavage?

#Unit 5. Developmental Biology
  1. In all mammalian embryos, the first cleavage is a normal meridional division; however, in the second cleavage, one of the two blastomeres divides equatorially and the other divides meridionally.
  2. Mammalian embryos increase exponentially from 2 to 4 to 8 cells, but frequently contain odd numbers of cells.
  3. Mammalian genome is inactivated during early cleavage and zygotically transcribed proteins are necessary for cleavage and development.
  4. Maternally encoded proteins can persist through most of the cleavage stages and play important roles in late stages of development.
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TLS Online TPP Program

#Question id: 3368

#Unit 11. Evolution and Behavior

The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of
TLS Online TPP Program

#Question id: 3369

#Unit 11. Evolution and Behavior

Genetic drift refers to random changes in allele frequencies over time leads to following consequence

a. Loss of genetic diversity per generation   

b. change in allelic frequency just by chance 

c. It caused adaptive evolution

d. It one allele may reach to 0 frequency
TLS Online TPP Program

#Question id: 3370

#Unit 11. Evolution and Behavior

One thousand independent populations of Drosophila are established with 25 individuals in each population, of which, one individual is of Aa genotype and the other nine are of AA genotype. If random genetic drift is the only mechanism acting on these populations, then, after a large number of generations, the expected number of populations fixed for the "a" allele is
TLS Online TPP Program

#Question id: 3371

#Unit 11. Evolution and Behavior

If a given gene in a randomly mating population has three alleles a, b and c in the ratio of 0.6, 0.3 and 0.1 respectively, what is the expected frequency of all heterozygote?
TLS Online TPP Program

#Question id: 3372

#Unit 11. Evolution and Behavior

Fish, penguin and Dolphin are independently evolved similar traits as a result of having to adapt to similar environments or ecological niches.

A. On a molecular level, this can happen due to random mutation in unrelated taxon to adaptive changes

B. This is the example of divergent evolution, occurred due to similar group of organisms inhabiting different environments

C. Similar phenotype are produced by identical change in orthologous gene

D. This is the example of convergent evolution, occurred due to similar group of organisms inhabiting different environments

Which of the following is the correct combination?
TLS Online TPP Program

#Question id: 3373

#Unit 11. Evolution and Behavior

Which of the following is correct statement?

A. Reproduction alone does not alter allelic or genotypic frequencies from generation to generation

B. Frequency of the heterozygote is always greatest when allelic frequencies are range between .33 and .66

C. Inbreeding is more likely to take place in nature when population size becomes very small and the number of mates is limited.

D. The movement of a few individuals between populations can counteract the effects of genetic drift