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

#Question id: 11050

#Unit 6. System Physiology – Plant

Three dimensional reconstructions of Arabidopsis sieve plates using a staining technique that can be used to image entire plant organs and Open sieve pores are visible as well as callose plug are also visible which technique used to analyze

#Question id: 7256

#Unit 5. Developmental Biology

Sox9 is an autosomal gene involved in several developmental processes, most notably bone formation. In the gonadal rudiments, Sox9 induces testis formation. Expression of the Sox9 gene is specifically upregulated by the combined expression of Sry and Sf1 proteins in Sertoli cell precursors. Thus, Sry may act merely as a “switch” operating during a very short time to activate Sox9, and the Sox9 protein may initiate the conserved evolutionary pathway to testis formation. Following statements are regarding to the functions of Sox9.

A. It appears to be able to activate its own promoter, thereby allowing it to be transcribed for long periods of time.

B. It activates the ability of β-catenin to induce ovary formation, either directly or indirectly.

C. It binds to cis-regulatory regions of numerous genes necessary for testis production.

D. Sox9 binds to the promoter site on the gene for anti-Müllerian hormone, providing a critical link in the pathway toward a male phenotype.

E. Sox9 inhibits the expression of the gene encoding Fgf9, a paracrine factor.

Which of the following statements are correct?

#Question id: 30079

#Unit 2. Cellular Organization

#Question id: 27503

#Unit 2. Cellular Organization

Bacterial DNA are atchitected in form of loop sized with

#Question id: 31289

#Unit 5. Developmental Biology