Question

which of the following is the correct?
dominant traits can not be expressed in heterozygous condition
recessive traits are always expressed in heterozygous condition
recessive traits are only expressed in heterozygous condition ​

Answer 1

Hey mate ,

The first one is false because :

In heterozygous individuals, only one allele, the dominant one, is able to express itself, while the other allele, the recessive, is hidden but still present. According to Mendelian Inheritance, an allele which cannot express itself in presence of other is recessive, hence can be expressed only in homozygous condition.

And the third one is also false :

So, the real ones is second because :

The heterozygous condition carries both dominant and recessive alleles, the presence of dominant allele masks the expression of the recessive allele. So, recessive alleles can be expressed only in homozygous conditions of any generation.

Hope it helps.