Given below are some of the statements that regulate the sucrose loading mechanism;

A) The solute potential or, more likely, the turgor pressure of the sieve elements

B) Sucrose concentration in the apoplast

C) The available number of symporter protein molecules

Possible observation given on how to avoid regulation;

i) increase in sieve element turgor above a certain threshold would lead to a compensatory increase in loading

ii) High sucrose concentrations in the apoplast would increase phloem loading

iii) SUT1 transporter mRNA and protein have been lower after 15 hours of darkness than after a light treatment. These data suggest that the concentration of SUT1 transporter molecules could regulate loading

iv) Decrease in sieve element turgor below a certain threshold would lead to a compensatory increase in loading

v) The transporter mRNA and protein high in darkness than lower in the light treatment

Which of the following combinations represents correct observation?

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#Question id: 13197

#Unit 1. Molecules and their Interaction Relevant to Biology

In helical nature of DNA is its periodicity each base pair is displaced (twisted) from the previous one by

TLS Online TPP Program

#Question id: 13196

#Unit 1. Molecules and their Interaction Relevant to Biology

 In The Mica Experiment Dnase I enzyme cleaves 

TLS Online TPP Program

#Question id: 13195

#Unit 1. Molecules and their Interaction Relevant to Biology

Who contributes to the stability of DNA helix structure?

A. Hydrogen bonding between bases

B. Hydrogen bonding between water and bases

C. Scattering interactions between bases

D. Stacking interactions between bases

CORRECT combination is

TLS Online TPP Program

#Question id: 13194

#Unit 1. Molecules and their Interaction Relevant to Biology

If we have the sequence 5’-ATGTC-3’ on one chain, the opposite chain must have the complementary sequence 

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#Question id: 13193

#Unit 1. Molecules and their Interaction Relevant to Biology

Data, collected from DNAs of a great many different species, led Chargaff to the following conclusions:

A. The base composition of DNA generally varies from one species to another.

B. DNA specimens isolated from different tissues of the same species have the different base composition.

C. The base composition of DNA in a given species changes with an organism’s age, nutritional state, or changing environment.

D. In all cellular DNAs, the sum of the purine residues equals the sum of the pyrimidine residues.

Which of the above statements are INCORRECT regarding Chargaff’s rule?

TLS Online TPP Program

#Question id: 10476

#Unit 1. Molecules and their Interaction Relevant to Biology

Following statements are regarding to gangliosides.

A. They are ceramides with attached oligosaccharides that include at least one sialic acid residue.

B. They are ceramides with attached oligosaccharides that include at least one phasphatidic acid residue.

C. Sialic acid gives gangliosides the negative charge at pH 7 that distinguishes them from globosides.

D. Gangliosides are primarily components of cell-surface membranes and constitute a significant fraction (6%) of brain lipids.

Which of the following combination is correct?