TLS Online TPP Program

#Question id: 3681


 A mutated E. coli cell carries out and completes DNA replication, but the lagging strands are found to contain more errors than normal. These errors are not found evenly distributed throughout the lagging strands, but are found in clusters. Which enzymatic activity is missing from this cell?

#Unit 3. Fundamental Processes
  1. the 3’→ 5’ exonuclease activity of pol III

  2. the 5’→ 3’ exonuclease activity of pol III

  3. the 3’→ 5’ exonuclease activity of pol I

  4. the 5’→ 3’ exonuclease activity of pol I

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TLS Online TPP Program

#Question id: 29111

#Unit 8. Inheritance Biology

A plant with purple flowers is crossed with a plant with white flowers, and the F1 are self-fertilized to produce 105 F2 progeny with purple flowers and 45 with white flowers.
A scientist hypothesized that there are two genes with identical functions that control the dominant trait. The scientist also proposed that the two genes are not linked. The scientist carried out a chi-square test to test the hypothesis. Which one of the following options is the correct chi-square value obtained by the scientist?

TLS Online TPP Program

#Question id: 29112

#Unit 8. Inheritance Biology

An example of multiple alleles is at a locus that determines the feather pattern of mallard ducks. One allele, M, produces the wild-type mallard pattern, MR, produces restricted, and a third allele, md, produces dusky. In this allelic series, dominancy shows MR >M > md
If a cross between  MR md X M md, What proportion of progeny will be restricted?

TLS Online TPP Program

#Question id: 29114

#Unit 8. Inheritance Biology

Given below, is the result of a complementation test for six independent mutants (1 to 6)

TLS Online TPP Program

#Question id: 29115

#Unit 8. Inheritance Biology

Given below, is the result of a complementation test for seven independent mutants (A to G). '+' represents complementation; '_' represents non complementation. Based on the above, which one of the following conclusions is correct


a) The mutations can be ordered in a three cistron as A-G-B-C-D-E-F

b) All mutations belong to a single cistron, but their order cannot be determined.

c) There are three cistrons, mutations A and G represent one cistron, B, C and D represent the second cistron and E and F represents the third cistron.

d) There are three linkage groups, mutations A and G  represent linkage group-I, B, C and D represent linkage group-II, and E and F represents linkage group-III

TLS Online TPP Program

#Question id: 29116

#Unit 6. System Physiology – Plant

Which one of the following is the correct order of during light reaction in the thylakoid membrane of chloroplast

TLS Online TPP Program

#Question id: 29117

#Unit 6. System Physiology – Plant

Light reactions of photosynthesis are carried out by four major protein complexes: Photosystem I (PSI), photosystem II (PSII), the cytochrome b6f complex and ATP synthase. The following are certain statements on PSII:
a. Red light absorbed by photosystem II (PSII) produces a strong oxidant and a weak reductant.
b. Far-red light absorbed by photosystem II (PSI) produces a weak oxidant and a strong reductant.
c. The strong oxidant generated by PSII oxidizes water,
d. The strong reductant generated by PSII oxidizes water
Which one of the following combinations of the above statements is correct?