Many eukaryotic genes contain a large number of exons. Correct splicing of such genes requires that neighboring exons be ligated to one another; if they are not, exons will be left out. One early proposal suggested that the splicing machinery bound to a splice site at one end of an intron and scanned through the intron to find the splice site at the other end. Such a scanning mechanism would guarantee that an exon was never skipped. This hypothesis was tested with one minigene with a duplicated 3ʹ splice site. Find diagram of the products you expect from minigene if the splicing machinery binds to a 3ʹ splice site and scans toward a 5ʹ splice site.

#Question id: 2534

#Unit 2. Cellular Organization

How the matrix polysaccharides are differ from the cellulose?

#Question id: 2535

#Unit 2. Cellular Organization

Expansins belong to a large superfamily of proteins, divided into two major expansin families, α-expansins (EXPAs) and β-expansins (EXPBs), what is the function of these two?

a) EXPAs are more active on eudicot cell walls,whereas EXPBs are more active on grass cell walls

b) EXPAs are more active on grass cell walls, whereas EXPBs are more active on eudicot cell walls

c) EXPAs loosen cellulose–cellulose junctions containing xyloglucan, whereas EXPBs loosen wall complexes containing GAX

d) EXPAs loosen wall complexes containing GAX, whereas EXPBs loosen cellulose–cellulose junctions containing xyloglucan

Which combination is correct from some given above functions of expansins,?

#Question id: 2536

#Unit 2. Cellular Organization

If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions ________.

#Question id: 2537

#Unit 2. Cellular Organization

Which of the following is the smallest structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope?

#Question id: 2538

#Unit 2. Cellular Organization

Which of the following frequently imposes a limit on cell size?

#Question id: 2539

#Unit 2. Cellular Organization

Which structure is common to plant and animal cells?