Question

Left thumb over right is dominant, and is represented with a capital C. Right thumb over left is recessive, and is represented with a lowercase c.
What would be the genotype of a person who naturally crosses his right thumb over his left when folding his hands together?

A) cc

B) Cc

C) CC or cc

D) CC or Cc

Answer 1

Answer: Option A) cc

Explanation:

• For a given gene, there are 2 or more alternative forms present, and they are known as alleles.
• The alleles are of two types - dominant and recessive.
• The dominant allele is the one which expresses itself in both heterozygous and homozygous condition in the phenotype.
• The recessive allele is the one which is only able to express itself in homozygous condition.
• Since, the right thumb over left allele c is recessive, the person who crosses right thumb over left must be a homozygote, and hence his genotype should be cc.