You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium. Next you isolate a mutation, designated MelB–, which gives uninducible melibiase activity. Mapping experiments show that MelB– is linked to Mel1. Using an F' factor that carries the chromosomal region surrounding Mel1, you perform the following genetic tests:

 

Describe the proposal for the type of regulatory functions affected by the MelB– mutation.

TLS Online TPP Program

#Question id: 10411

#I Life Science/ Life Sciences Group – I-V

Phytochrome chromophore which absorbs light known as Phytochromobilin , that are synthesized in

TLS Online TPP Program

#Question id: 10411

#SCPH05 I Biotechnology

Phytochrome chromophore which absorbs light known as Phytochromobilin , that are synthesized in

TLS Online TPP Program

#Question id: 10411

#SCPH06 I Botany

Phytochrome chromophore which absorbs light known as Phytochromobilin , that are synthesized in

TLS Online TPP Program

#Question id: 10412

#SCPH05 I Biotechnology

Red and far-red lights are perceived by plants through various photoreceptors including phytochromes. The red/far-red reversibility of seed germination was due to the-

a) photoreversibility of phytochrome

b) presence of red and far-red light at different fluence rate

c) Conversion of Pr to Pfr form through the effect of red light

d) equal proportion of red and far red light at same fluence rate

Which of the following combinations is correct?

TLS Online TPP Program

#Question id: 10412

#SCPH06 I Botany

Red and far-red lights are perceived by plants through various photoreceptors including phytochromes. The red/far-red reversibility of seed germination was due to the-

a) photoreversibility of phytochrome

b) presence of red and far-red light at different fluence rate

c) Conversion of Pr to Pfr form through the effect of red light

d) equal proportion of red and far red light at same fluence rate

Which of the following combinations is correct?

TLS Online TPP Program

#Question id: 10413

#SCPH05 I Biotechnology

Following are certain statements are related to the effect of red and far-red light;

a) under a dense canopy much of the red light is absorbed by plant pigments, resulting in transmittance of mostly far-red light

b) Pr (red) has highest photon flux at 680 nm while Pfr (far-red) has highest photon flux at 730nm

c) Pfr far-red light–absorbing form, which is considered to be the physiologically active form of phytochrome

d) R:FR ratio is strongly affected by the presence of a canopy because chlorophyll absorbs far-red but not red light

Which one of the combinations of above statements is incorrect?