Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETZoologyPrinciples of Inheritance and Variation

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Human skin colour is considered a polygenic trait where the phenotype reflects the additive contribution of each allele. Reason (R): Polygenic traits are controlled by three or more genes and their phenotypic expression is strictly independent of environmental influences. In the light of the above

Options

  1. ABoth Assertion and Reason are true and Reason is the correct explanation of Assertion
  2. BAssertion is true but Reason is false
  3. CBoth Assertion and Reason are true but Reason is not the correct explanation of Assertion
  4. DAssertion is false but Reason is true

Correct answer

B. Assertion is true but Reason is false

Step-by-step solution

Assertion (A) is true because human skin colour is a classic example of polygenic inheritance, where the effect of each allele is additive, resulting in a gradient of phenotypes. Reason (R) is false because, according to NCERT, polygenic inheritance also takes into account the influence of the environment. The phenotypic expression of polygenic traits is not strictly independent of environmental factors. Therefore, Assertion is true but Reason is false. Answer: Assertion is true but Reason is false

Practice Principles of Inheritance and Variation on Quantrex Academy →

More from Principles of Inheritance and Variation

Match List I with List II : List I List II A. Incomplete dominance I. Human skin colour B. Co-dominance II. Inheritance of flower colour in Antirrhinum sp. C. Pleiotropy III. Pheny 2026The sixth mutant codon of beta globin gene causing polymerization of Haemoglobin and change in RBC shape is : 2026In a population of a grasshopper species, the chromosome number of some members is 23 and some other members possess 24 chromosomes. The 23 and 24 chromosome-bearing members in thi 2026Which one of the following disorders is caused by the substitution of Glutamic acid (Glu) by Valine (Val) at the sixth position of the beta globin chain of the haemoglobin molecule 2026What is the probability of having children with 'O' blood group, where both mother and father are heterozygous for 'A' and 'B' blood group, respectively ? 2026Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : In an experiment, Mendel observed that the F1 progeny plants a 2026Given below are two statements : Statement I : Down's syndrome is caused by the absence of one of the X-chromosomes. Statement II : Turner's syndrome is caused by the presence of a 2026Which of the following statements are true with reference to the sex-determination in honeybees ? A. An offspring formed from the union of a sperm and an egg, develops as a female 2026 Full Principles of Inheritance and Variation list All NEET PYQs