TLS Online TPP Program

#Question id: 12519


Some given  statements about biosynthesis of Abscisic acid ;
a) ABA is synthesized in almost all cells that contain chloroplasts or amyloplasts
b) ABA is a 15-carbon terpenoid, or sesquiterpenoid, which is synthesized in plants by an indirect pathway via 40-carbon carotenoid intermediates
c) Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting
d) Oxidation by ABA-8′-hydroxylases lead to ABA inactivation, ABA can also be inactivated by conjugation, but this is irreversible. Both types of inactivation are also tightly regulated.
Which of the following  combination from the above statements  is correct?

#Unit 6. System Physiology – Plant
  1. B, C and D
  2. A, C and D
  3. A, B and C
  4. A and D only
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TLS Online TPP Program

#Question id: 3390

#Unit 11. Evolution and Behavior

The average numbers of offspring produced by three genotypes are: GG = 60; Gg = 30, gg = 20. What is the selection coefficient of gg?

TLS Online TPP Program

#Question id: 3391

#Unit 11. Evolution and Behavior

Which of the following statements is an example of genetic drift?

a. Allele g for fat production increases in a small population because birds with more body fat have higher survivorship in a harsh winter.

b. Random mutation increases the frequency of allele A in one population but not in another.

c. Allele R reaches a frequency of 1.0 because individuals with genotype rr are sterile.

d. Allele m is lost when a virus kills all but a few individuals and just by chance none of the survivors possess allele m

TLS Online TPP Program

#Question id: 3392

#Unit 11. Evolution and Behavior

Color blindness is X linked recessive disorder. X+ chromosome carry a normal allele but Xc chromosome carries defective allele. When frequency of colorblindness female (0.10), colorblind male (0.30) and heterozygous female (0.20). Random matting population, what will be frequency of carrier female?

TLS Online TPP Program

#Question id: 3393

#Unit 11. Evolution and Behavior

Natural Selection can maintain a polymorphism when

a. heterozygote is fitter than the homozygote

b. Fitnesses of genotypes are negatively frequency dependent.

c. Fitnesses of genotypes are positive frequency dependent.

d. One homozygote is fitter than the heterozygote

TLS Online TPP Program

#Question id: 3394

#Unit 11. Evolution and Behavior

All genetic drift arises from sampling error.  There are several different ways in which sampling error can arise as a following

a. Reduced population size      b. Founder effect

c. Genetic bottleneck                d. Differ in sex ratio

Which of the following above way cause sampling error in succeed generation?

TLS Online TPP Program

#Question id: 3395

#Unit 11. Evolution and Behavior

The Hardy-Weinberg principle states that allele frequencies in a population will remain constant over generations if certain assumptions are met.

A. Random mating

B. Sexual selection

C. Migration

D. Large population size

E. Reproductive isolated from other population

F. Linkage of many genes

Which of the above factors will cause changes in allele frequencies overgenerations?