TLS Online TPP Program

#Question id: 24165


When winding an old clock, it is important not to overwind it. Overwinding occurs when the mainspring is almost fully wound, but the operator continues to turn the winding key. This causes the main spring to coil too tightly, and might even break it.

This paragraph best supports the statement that

#Unit 1. Molecules and their Interaction Relevant to Biology
  1. clocks have changed over the years.
  2. old-fashioned clocks become fragile with age.
  3. old-fashioned clocks were operated by an internal spring.
  4. overwinding clocks used to be a common mistake
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TLS Online TPP Program

#Question id: 12696

#Unit 8. Inheritance Biology

The following is a schematic representation of region of the chromosome of fly along with extent of six deletions (Del 1 to Del 6); 
When flies homozygous for the recessive mutations are crossed with flies heterozygous for the deletions, the following results are obtained, in which "m" represents a mutant phenotype and a plus sign (+) represents the wild type. On the basis of these data, determine the relative order of the seven mutant eenes on the chromosome. 

TLS Online TPP Program

#Question id: 5220

#Unit 11. Evolution and Behavior

In comparing the genomes of humans and those of other higher primates, it is seen that humans have a large metacentric pair we call chromosome #2 among our 46 chromosomes, while the other primates of this group have 48 chromosomes and any pair like the human #2 pair is not present; instead the primate groups each have two pairs of midsize acrocentric chromosomes. What is the most likely explanation?

TLS Online TPP Program

#Question id: 12251

#Unit 10. Ecological Principles

A plant produces flowers that are open through the day and the night. An experimenter places pollen on the stigmas of freshly opened flowers and covers them after pollination to prevent natural pollinators from having access to the flowers. When experimental pollination was carried out during the day, 40% of the flowers yielded fruit. When experimental pollination was carried out during the night, 80% of the flowers yielded fruit. However, when flowers were  kept  open  to  natural  pollination  during  the  day  (covered  at  night),  35%  of  flowers  produced  fruit.  20%  of flowers exposed to natural pollination during the night (covered during the day) produced fruit. Which of the following statements is NOT a plausible explanation of these results ?

TLS Online TPP Program

#Question id: 12720

#Unit 6. System Physiology – Plant

Several genes coding for enzymes associated with osmotic adjustment are turned on (up-regulated) by osmotic stress and/or salinity, and cold stress. These genes encode enzymes such as the following;
I) ∆′1-Pyrroline-5-carboxylate synthase, a key enzyme in the proline biosynthetic pathway
II) myo-Inositol 6-O-methyltransferase, a rate-limiting enzyme in the accumulation of the cyclic sugar alcohol called pinitol
III) Betaine aldehyde dehydrogenase, an enzyme involved in glycine betaine accumulation
Given following statements of gene encoding enzyme is correct?

TLS Online TPP Program

#Question id: 1098

#Unit 4. Cell Communication and Cell Signaling

Which of the following is the most plausible explanation for why an animal cell would be unable to reduce the Ca2+ concentration in its cytosol compared with the extracellular fluid?