This feature is an adaptive, as the redistribution of chloroplasts within the cells modulates light absorption and prevents photodamage, diagram shows of chloroplast distribution patterns in Arabidopsis palisade cells in response to different light intensities;

                                        

m) A-low light, B-high light, C-darkness

n) A-high light, B-darkness, C-low light

Based on the above light intensities, each shows different chloroplasts position such as,

i) chloroplasts avoid sunlight by migrating to the side walls of palisade cells

ii) chloroplasts move to the bottom of the cell, although the physiological function of this position is unclear

iii) chloroplasts optimize light absorption by accumulating at the upper and lower sides of palisade cells

Which of the following correct combinations shows light intensities and chloroplast movements?

#Question id: 735

#Unit 1. Molecules and their Interaction Relevant to Biology

The a-keratin chains indicated by the diagram below have undergone one chemical step. To alter the shape of the a-keratin chains—as in hair waving—what subsequent steps are required?

#Question id: 734

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements is true for two different tripeptides consisting of either glycine or proline?

#Question id: 733

#Unit 1. Molecules and their Interaction Relevant to Biology

Which one of the statements on protein conformation, detailed below is INCORRECT?

#Question id: 732

#Unit 1. Molecules and their Interaction Relevant to Biology

Ramachandran plots can help increase the accuracy of models derived from x-ray crystallography data. The plot below was created by measuring phi, and psi for each amino acid residue in a 2.2 A resolution crystal structure. In the plot, which excludes Gly and Pro residues, selected residues (dots) are numbered 1 through 5.

Which of the following statements can be correctly stated for this plot in reference to selected residues?

A. Residues 1 and 3 are in either B sheets

B. residue 2 is in a right-handed a helix, and residue 4 is in a left-handed a helix.

C. If residue 5 were Gly, it might be in an acceptable position in the plot

#Question id: 731

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following structure is mentioned in the given Ramachandran plot

#Question id: 729

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct about the collagen triple-helix domain

a. is rich in glycine.                             b. is rich in proline.

c. is rich in hydroxyproline.                d. is an alpha helix.