Question

Select the group of CORRECT statements.
I. If phenotype of offsprings shows only the dominant trait then the parent plants are heterozygous.
II. A true breeding line shows stable trait inheritance and expression for several generations.
III. In mendelian experiment material, contrasting characters can be easily recognized.
IV. When a single gene controls two (or more) different traits, it is called polygene.
V. When interactions occurs between the alleles of different genes present on the same or different chromosome it is called intragenic interaction.

पर्याय

• III and V only

• II and III only

• III and IV only

• I and V only

Answer 1

II and III only

Explanation:

• Statement II is correct: A true breeding line, after continuous self‑pollination, shows stable trait inheritance and expression for several generations.
• Statement III is correct: In Mendelian experiments, parental lines are chosen so that contrasting characters (tall/dwarf, yellow/green etc.) can be easily recognized.
• I is incorrect: If offspring show only the dominant trait, parents may be homozygous or heterozygous, not necessarily both heterozygous.
• IV is incorrect: A single gene controlling multiple traits is pleiotropy; polygenes are multiple genes together controlling one trait.
• V is incorrect: Interaction between alleles of different genes is intergenic/intergenic interaction or epistasis, not intragenic interaction.