11 Individuals heterozygous for a dominant eye mutation S have small eyes. The S

Question

11 Individuals heterozygous for a dominant eye mutation S have small eyes. The S allele is also associated with recessive lethality. When two heterozygotes are crossed, normal-eyed and small eyed individuals are expected in a A 1:1 ratio 2:1 ratio 1:2 ratio 1:3 ratio 3:1 ratio Mendels law of independent assortment has its physical basis in the separation of alleles into haploid cells spindle attachment in anaphasel random arrangement of chromosomes on the metaphase plate in meiosisl formation of new cell walls none of the above S? D E 12 A B C D E 0

Explanation / Answer

11) Individuals heterozygous for a dominant eye mutation S have small eyes. The S allele is also associated with recessive lethality. Normally when two heterozygotes are crossed, the expected phenotypic ratio is 3:1 and the expected genotypic ratio is 1:2:1. Here, since S allele is associated with recessive lethality, only heterozygotes (Ss) and homozygotes of genotype (ss) will survive. So, here the genotypic ratio of small eyed (Ss) and normal eyed (ss) will be 2:1. The ratio of normal eyed to small eyed is therefore 1:2 (option C).

12) Mendel's law of independent assortment has its physical basis in the separation of alleles into haploid cells (option a).

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.