In individuals heterozygous for a chromosome inversion, the homologous chromosomes form a loop in prophase I of meiosis.

Which of the following is effect of inversion?

A. A dicentric and an acentric chromosome in meiosis I as the chiasmata gets terminated when inversion includes centromere  

B. Appearance of deletion and duplication in both the cross over products chromosomes when centromere outside of inversion region  

C. All recombinant gamete are non-viable gametes when single crossing over within inverted region; irrespective to paracentric or pericentic inversion

D. Nonviable gametes are usually produced, resulting in a depression in observed recombination frequencies.

Which of the above statements are correct?

#Question id: 18960

#Unit 13. Methods in Biology

#Question id: 1520

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to enzymatic processing of benzo(a)pyrene to a more potent mutagen and carcinogen.

A. Liver enzymes, particularly P-450 enzymes, modify benzo(a)pyrene in a series of reactions, producing 7,8-diol-9,10-epoxide, a highly potent mutagenic species that reacts with DNA primarily at the N2 atom of a guanine base.

B. The adduct, (+)-trans-anti-B(a)P-N2-dG, causes polymerase to insert an A rather than a C opposite the modified G base. Next time the DNA is replicated, a T will be inserted opposite the A, and the mutation will be complete.

C. Potent mutagen majorly causes conversion of guanine (G) to thymine (T) bases, a transition mutation.

D. When this potent mutagen applied to cultured bronchial epithelial cells, activated benzo(a)pyrene induces many mutations, including activating mutations at codons 175, 248, and 273 of the p53 gene.

Which of the following statements are correct?

#Question id: 11999

#Unit 10. Ecological Principles

#Question id: 1377

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements apply to both eukaryotic cell walls and animal cell extracellular matrices? Please select all that apply.

a) They are inflexible structures that support cells.

b) They are built to a common overall structure that can be described as 'fibres in a matrix'.

c) Their protein components are synthesized by ribosomes of the rough endoplasmic reticulum.

d) They limit the diffusion of ions and small molecules into the cell.

#Question id: 12887

#General Aptitude