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TLS Online TPP Program

#Question id: 646

Many biosynthetic pathways are regulated by feedback inhibition of enzymes. In a particular type of feedback inhibition, two endproducts individually do not inhibit an enzyme upstream in the pathway at all, but when both are present they inhibit the same enzyme significantly. What type of feedback inhibition do these inhibitors represent?

#Unit 1. Molecules and their Interaction Relevant to Biology

  1. Additive inhibition

  2. Concerted inhibition 

  3. Cumulative inhibition 

  4. Synergistic inhibition

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TLS Online TPP Program

#Question id: 19470

#Unit 12. Applied Biology

From where did this GOX gene has been isolated from and expressed in transgenic plants?
TLS Online TPP Program

#Question id: 4779

#Unit 8. Inheritance Biology

Fruit color in eggplant due to interaction of three non-allelic genes A, B and C.  These three non-allelic genes are produce purple phenotype when they come together or separately. Following some genotype and their phenotype is given.

                                  A- -- --         Purple

                                 -- B- --         Purple

                                 -- -- C-         purple

                                 aabbcc         White    

 A Plant genotype AaBbcc was cross to plant with genotype aabbcc. What is probability of white phenotype among their offspring?
TLS Online TPP Program

#Question id: 7077

#Unit 5. Developmental Biology

In the zygote, the cortical cytoplasm rotates about 30ยบ with respect to the internal cytoplasm, this exposes a region of inner cytoplasm directly opposite the sperm entry point. This region is called as:
TLS Online TPP Program

#Question id: 15152

#Unit 8. Inheritance Biology

In this problem we will explore some of the many ways that mutations in two different genes can interact to produce different Mendelian ratios. Consider a hypothetical insect species that has red eyes. Imagine mutations in two different unlinked genes that can, in certain combinations, block the formation of red eye pigment yielding mutants with white eyes. In principle, there are two different possible arrangements for two biochemical steps responsible for the formation of red eye pigment. The two genes might act in series such that a mutation in either gene would block the formation of red pigment. Alternatively, the two genes could act in parallel such that mutations in both genes would be required to block the formation of red pigment.
Further complexity arises from the possibility that mutations in either gene that lead to a block in enzymatic activity could be either dominant or recessive. If the crosses is made between a wild type insect with red eyes and a true breeding white eyed strain with mutations in both genes. Such considerations yield the Pathways in series with dominant mutations in both genes, determine the phenotype of the F1 progeny and the expected phenotypic ratio of red to white eyed insects in the F2.
TLS Online TPP Program

#Question id: 861

#Unit 1. Molecules and their Interaction Relevant to Biology

Alexander Varshavsky discovered, the half-lives of many cytoplasmic proteins vary with the identities of their N-terminal residues via the so-called N-end rule:-

A. Destabilizing N-terminal residues Asp, Arg, Leu, Lys, and Phe have half-lives of

i. Only 2 to 3 minutes,

B. Stabilizing N-terminal residues Ala, Gly, Met, Ser, Thr, and Val have half-lives of

ii. >10 hours in prokaryotes

iii. >20 hours in eukaryotes.