#Question id: 4408
#Unit 3. Fundamental Processes
an example/s of in vivo “molecular mimicry” is/are
I. EF-G–GDP and EF-Tu–GTP–tRNA
II. TAF42 -TAF62 and H3.H4 tetramer
III. Tyrosinyl-tRNA and Puromycin
#Question id: 4514
#Unit 3. Fundamental Processes
What is true about coactivators,
A. The coactivators act directly by binding to the DNA
B. The coactivators act indirectly—not by binding to the DNA
C. Are required for essential communication between the activators and the complex composed of Pol II.
D. Are required for essential communication between the and the basal (or general) transcription factors.
#Question id: 11124
#Unit 9. Diversity of Life Forms
A researcher compared the nucleotide sequences of a homologous gene from five different species of mammals with the homologous human gene. The sequence homology between each speciesʹ version of the gene and the human gene is presented as a percentage of similarity.
What probably explains the inclusion of rabbits in this research?
#Question id: 4109
#Unit 3. Fundamental Processes
When E. coli is grown on a medium containing a mixture of glucose and lactose, it proliferates with complex kinetics. The bacteria proliferate faster at the beginning than at the end, and there is a lag between these two phases when they virtually stop dividing. Assays of the concentrations of the two sugars in the medium show that glucose falls to very low levels after a few cell doublings, but lactose remains high until near the end of the experimental time course (not shown). Although the concentration of lactose is high throughout most of the experiment, β-galactosidase, which is regulated as part of the Lac operon, is not induced until more than 100 minutes have passed. Choose correct explanation why the Lac operon is not induced by lactose during the rapid initial phase of bacterial proliferation
A. The rapid bacterial growth at the beginning of the experiment results from the metabolism of glucose. The slower growth at the end results from metabolism of lactose.
B. CAP and the Lac repressor mediate induction in the situation
C. The bacteria stopped growing in the middle of the experiment because they ran out of glucose but did not yet possess the enzymes necessary for lactose metabolism
D. Induction of the Lac operon requires that two conditions be met: lactose must be present and glucose must be absent.
#Question id: 10906
#Unit 6. System Physiology – Plant
The pressure-flow model explains phloem translocation as a flow of solution (bulk flow) driven by an osmotically generated pressure gradient between source and sink.
a) Phloem translocation, both active and passive mechanisms were considered. All theories, both active and passive, assume an energy requirement in both sources and sinks.
b) In sources, energy is necessary to move photosynthate from producing cells into the sieve elements. This movement of photosynthate is called phloem loading.
c) In sinks, energy is essential for some aspects of movement from sieve elements to sink cells, which store or metabolize the sugar. This movement of photosynthate from sieve elements to sink cells is called phloem unloading.
d) The Active mechanisms of phloem transport further assume that energy is required in the sieve elements of the path between sources and sinks simply to maintain structures.
From the given statements find out the correct for pressure-flow model.