#Question id: 10348
#Unit 6. System Physiology – Plant
During ammonium assimilation, requires two enzymes converting ammonium to amino acids. Each of which is Glutamine synthetase (GS), given below some statements about GS ;
a) GS transfers the amide group of glutamine to 2-oxoglutarate, yielding two molecules of glutamate
b) it requires a divalent cation such as Mg2+, Mn2+, or Co2+ as a cofactor
c) Plants contain two classes of GS, one in the cytosol and the other in root plastids or shoot chloroplasts
d) The cytosolic forms are expressed in germinating seeds or in the vascular bundles of roots and shoots and produce glutamate for intercellular nitrogen transport
e) The GS in root plastids generates amide nitrogen for local consumption; the GS in shoot chloroplasts reassimilates photorespiratory NH4+
f) Light and carbohydrate levels alter the expression of the cytosolic forms of the enzyme, but they have little effect on the plastid forms.
Which of the following statements is correct?
#Question id: 4960
#Unit 11. Evolution and Behavior
Letʹs say that a hypothetical submersible robot was used to collect samples of sedimentary rock from the sea floor along the section illustrated. The robot moved back and forth along the transect, collecting first from site A, then site III, then site B, then site II, and lastly site D. Assuming that sedimentation has occurred at a constant rate along the transect over the past million years, rearrange the sites mentioned above on the basis of the thickness of the sediments overlying the igneous rock, from thickest to thinnest.
#Question id: 2318
#Unit 2. Cellular Organization
What plant organelle serves a function similar to that of animal lysosomes?
#Question id: 10765
#Unit 8. Inheritance Biology
#Question id: 4091
#Unit 3. Fundamental Processes
To avoid being degraded by nuclear exonucleases, nascent transcripts, pre-mRNA-processing intermediates, and mature mRNAs in the nucleus must have their ends protected. Which of the following mechanism are present in the cell to protect mRNA from degradation?
I. The 5′ cap is protected because it is bound by a heterodimeric nuclear cap-binding complex (CBC), which protects it from 5′ exonucleases and also functions in export of the mRNA to the cytoplasm.
II. 5’-5’ phosphodiester bond in the cap of mRNA plays crucial role in protection
III. The 3′ end of a nascent transcript lies within the RNA polymerase and is thus inaccessible to exonucleases