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#Question id: 13142


The Norway rat (Rattus Norvegicus), a widespread pest, was controlled for about a decade by the anticoagulant warfarin. This chemical substance, placed in food pellets, is absorbed by the intestinal tract and inhibits the clotting of blood. After a population decline for about 10 years, rat populations increased and stabilized. In one European population, as illustrated in the graph below, the percentage of rats resistant to warfarin has remained fairly stable over a number of years.

Resistance to warfarin is governed by a dominant autosomal gene, R. More than 15 percent of the resistant animals are heterozygous at this locus (Rr). The table below indicates the response to warfarin and relative reproductive fitness of individuals that are homozygous or heterozygous for the dominant gene (R). The RR individuals have a 20-fold increase in vitamin K requirement over individuals.

Fitness is a measure of the reproductive success of a particular genotype. The highest fitness is 1.00.
There is a substantial number of heterozygotes in the population. Which of the following is the best explanation of this observation?

#Unit 10. Ecological Principles
  1. Heterozygotes (Rr) have a selective advantage over both homozygotes (RR and rr). 
  2. The gene for susceptibility (r) is increasing rapidly each generation.
  3. The gene for susceptibility (r) is being lost by chance each generation.
  4. Dominant homozygotes (RR) enjoy a reproductive advantage over heterozygotes
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TLS Online TPP Program

#Question id: 4919

#Unit 8. Inheritance Biology

Genes for cytoplasmic male sterility in plants are generally located in

TLS Online TPP Program

#Question id: 4920

#Unit 8. Inheritance Biology

In Neurospora, the mutant stp exhibits erratic stop-and start growth. When a female of stp strain is crossed with a normal strain acting as a male, all progeny individuals' showed stp mutant phenotype. However, the reciprocal cross resulted in all normal progeny, individuals. These results can be explained on the basis of

A. Uniparental gene contribution

B. Nuclear inheritance with concept of dominance

C. Sex link character

D. stp mutation may be located in chloroplast DNA

The most appropriate statement or combination of the above statements for explaining the experimental results is:

TLS Online TPP Program

#Question id: 4921

#Unit 8. Inheritance Biology

Shell coiling in snail determine by genetic maternal effect. S for dextral and s for sinistral.  Following cross allowed between

Male

Female

Progeny   (Genotype)

Dextral

sinistral

Dextral (K1)

Dextral

Sinistral

Sinistral (K2)

Sinistral

sinistral

Dextral (K3)

Dextral

Dextral

Sinistral (K4)

Which of the following progeny not have SS genotype?

TLS Online TPP Program

#Question id: 4922

#Unit 8. Inheritance Biology

Following statement is correct for Genetic maternal effect. 

A- Characteristics are determined by autosomal genes

B- Inherited according to Mendel’s principles

C- Phenotype of offspring determine by protein factor that is inherited via egg cytoplasm

TLS Online TPP Program

#Question id: 4923

#Unit 8. Inheritance Biology

following statement given for Genetic maternal effect are correct?

A- Characteristics are determined by nuclear gene

B- Inherited according to Mendel’s principles

C- In F3 generation, segregation of Dominant trait and recessive trait in ratio of 3:1

D) No Segregation of Trait in F2 generation 

TLS Online TPP Program

#Question id: 4924

#Unit 8. Inheritance Biology

Following statement given for a character

A- Characteristics based on autosomal genes

B- Biparntal inheritance

C-pattern of gene expression depend on parental origin

Which of the following having above statements feature?