#Question id: 10462
#Unit 6. System Physiology – Plant
During an experiments mutating the conserved cysteine in the LOV1 domain of phot1 does not affect phototropic responsiveness (the seedlings bend toward blue light) whereas the equivalent mutation in LOV2 abolishes the response. What will be the conclusion has been drawn from this experiments?
a) LOV1 domain is secondarily responsible (primarily responsible is LOV2 domain) for kinase activation and LOV1 is not is coupled with the protein region Jα-helix that’s why it does not affect phototropic responsiveness
b) These studies have demonstrated that LOV2 domain is primarily responsible for kinase activation in response to blue light
c) This is due in part to the position of LOV2 within the phototropin molecule, where it is coupled to a protein region known as the Jα-helix
d) The function of LOV2 domain is thought to play a role in receptor dimerization by accomplishing the kinase activation in response to blue light
Which of the correct conclusion drawn from the above experiment?
#Question id: 7178
#Unit 5. Developmental Biology
In sea urchin, the large micromeres are autonomously specified. They inherit maternal determinants that were deposited at the vegetal hemisphere of the egg; these become incorporated into the large micromeres at fourth cleavage. When an isolated animal hemisphere is combined with isolated micromeres, then what will be the result?
#Question id: 1513
#Unit 4. Cell Communication and Cell Signaling
The kinase activity of ATM is activated in response to DNA damage due to various stresses (e.g., UV irradiation, heat). Activated ATM then triggers following pathways leading to arrest in G1.
A. Chk2 is phosphorylated and, in turn, phosphorylates Cdc25A, thereby marking it for degradation and blocking its role in CDK2 activation.
B. Phosphorylation of p53 stabilizes it, permitting p53-activated expression of genes encoding proteins that cause arrest in G1, promote apoptosis, or participate in DNA repair.
C. Controlling the pool of p53, ATM phosphorylates MDM2 to inactivate it, causing increased stabilization of p53. Another protein p14ARF inhibits the activity of Mdm2 thus stabilizing p53.
Based on the above information, which one of the following statements is correct?
#Question id: 8701
#Unit 9. Diversity of Life Forms
The question refers to the following table, which compares the percent sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (for example, Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A.
Based on the tabular data, and assuming that time advances vertically, which phylogenetic tree is the most likely depiction of the evolutionary relationships among these five species?
#Question id: 19069
#Unit 6. System Physiology – Plant