TLS Online TPP Program

#Question id: 3292


Which of the following is correct observation?

#Unit 11. Evolution and Behavior
  1. Niche partitioning allows for selection of differential patterns of resource usage, which can drive speciation

  2. This narrowing of phenotypes causes a reduction in genetic diversity in a population

  3. Extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype

  4. The phenotypes grade become wide and caused increases the genetic diversity in a population

More Questions
TLS Online TPP Program

#Question id: 7273

#Unit 5. Developmental Biology

Hox9 and Hox10 paralogues specify the stylopod, Hox11 paralogues specify the zeugopod, and Hox12 and Hox13 paralogues specify the autopod. This scenario has been confirmed by numerous experiments.

Which of the following experiment correctly describe this scenario?

TLS Online TPP Program

#Question id: 7272

#Unit 5. Developmental Biology

Few statements regarding the role of disheveled (dsh) and beta-catenin in the development of sea urchin.

A. beta-catenin accumulates predominantly in the macromeres and somewhat in veg2 tier cells.

B. At the fourth cleavage disheveled and β-catenin, both of which are found in the cytoplasm and are inherited by the micromeres.

C. Treating sea urchin embryos with lithium chloride allows β-catenin to accumulate in every cell and transforms presumptive ectoderm into endoderm.

D. When β-catenin is prevented from entering the nuclei (i.e., it remains in the cytoplasm), the vegetal cell fates are specified, and the entire embryo develops as a ciliated ectodermal ball.

Which one of the following options represents a combination of correct statement?

TLS Online TPP Program

#Question id: 7271

#Unit 5. Developmental Biology

In drosophila, Head formation required higher Bicoid concentrations than thorax formation, because

TLS Online TPP Program

#Question id: 7270

#Unit 5. Developmental Biology

According to this figure which of the following option is incorrect?

TLS Online TPP Program

#Question id: 7269

#Unit 5. Developmental Biology

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?

TLS Online TPP Program

#Question id: 7268

#Unit 5. Developmental Biology

Match the columns and choose the correct option.

Column I           

Column II

A.    Progress zone

i.                    thickening of the ectoderm at the apex of the developing limb bud

 

B.     Apical ectodermal ridge

ii.                  The cells found within the most posterior region

C.     Zone of polarizing activity

iii.                The highly proliferative mesenchyme that fuels limb bud growth