Following statements are regarding to gastrulation in chick embryo.

A. During gastrulation, future mesodermal and endodermal cells migrate from the epiblast through the primitive streak into the interior of the blastoderm.

B. An aggregation of cells, known as Hensen’s node, forms at the posterior end of the streak.

C. As the streak extends, cells of the epiblast move toward the primitive streak, through it, and then outward again underneath the surface to give rise internally to the mesoderm and endoderm, the latter displacing a lower layer of cells called the endoblast.

D. Cells that remain in the epiblast form the endoderm.

Which of the following statements are correct?

#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

#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

#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?

#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?

#Question id: 3263

#Unit 11. Evolution and Behavior

From an evolutionary point of view, plant tendrils derived from leaves and those derived from stems are examples of

#Question id: 3264

#Unit 11. Evolution and Behavior

Which of the following is (are) true of natural selection?