#Question id: 2851
#Unit 2. Cellular Organization
There is a growing body of evidence that acetylation of histone N-termini in specific chromosomal regions contributes to gene control by regulating the binding of histones to DNA and regulation of the folding state of chromatin. The extent of histone acetylation is correlated with the relative resistance of chromatin DNA to digestion by nucleases. Which combination of histone acetylation state and DNAse 1 resistance is characteristic of actively transcribed regions of chromatin?
#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: 11287
#Unit 10. Ecological Principles
What is value of evenness in community 3 and 4 respectively?
#Question id: 10304
#Unit 6. System Physiology – Plant
Pyruvate is coverted into the Acetyl-CoA, Acetyl-CoA contain the acetyl group which are comes from the pyruvate and Coenzyme A (CoA) that contain other groups such as;
a) A reactive thiol (—SH) group that is critical to the role of CoA as an acyl carrier in a number of metabolic reactions
b) contain pantothenic acid, A hydroxyl group of pantothenic acid is joined to a modified ADP moiety by a phosphate ester bond
c) pantothenic acid carboxyl group is attached to β-mercaptoethylamine in amide linkage
d) Hydroxyl group at the 3’ position of the ADP moiety has a phosphoryl group not present in free ADP
which of the following correct observation about Coenzyme A (CoA)?
#Question id: 28732
#Unit 2. Cellular Organization
A proteins containing a Tyr-X-X-Φ sequence bind to Vesicles coated with_____