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: 792

#Unit 1. Molecules and their Interaction Relevant to Biology

Which arm of the tRNA can act as a structural recognition feature?

#Question id: 793

#Unit 1. Molecules and their Interaction Relevant to Biology

What is the average size (in bp) of a mature t-RNA?

#Question id: 794

#Unit 1. Molecules and their Interaction Relevant to Biology

A single-stranded DNA molecule contains 40 nucleotides with equal amounts of A, C, G, and T. This DNA strand can combine with a complementary DNA strand to form a double-stranded DNA molecule. Which structural feature is found in the single-stranded DNA molecule?

#Question id: 795

#Unit 1. Molecules and their Interaction Relevant to Biology

A single-stranded DNA molecule contains 40 nucleotides and has the sequence 5’-(GA)20-3’. When this single strand binds to a complementary DNA strand,

#Question id: 796

#Unit 1. Molecules and their Interaction Relevant to Biology

Which statement best describes the distinction between the purposes of the two RNAi pathways within the eukaryotic cell?

#Question id: 797

#Unit 1. Molecules and their Interaction Relevant to Biology

With respect to microRNAs, which, if any, of the following statements, is FALSE?)

A. MicroRNA genes often occur in gene clusters within introns of protein-coding genes and are usually transcribed by RNA polymerase II.

B. Like an mRNA a miRNA is initially produced as a larger precursor RNA that, like the great majority of mRNAs, usually has a 5’ cap and a poly(A) tail.

C. MicroRNAs are produced by germ-line cells only.

D. A miRNA is initially produced as a duplex RNA but in order to work it needs to be converted into a single-strand RNA.

E. MicroRNAs usually work as transcription factors.