Question

Which statement about the genotypes of organisms is correct? 

A. Dominant alleles are only found in homozygotes 

B. One recessive allele always causes a recessive phenotype. 

C. Recessive phenotypes must be homozygous 

D. The dominant phenotype must be heterozygous

Answer 1

Allele which can express themselves in heterozygous conditions are dominant alleles while which does not are recessive allele. 

Due to this reason, recessive allele is able to express themselves in a homozygous condition only. 

TT has a phenotype of tall height & Tt also has a phenotype of tall height but tt is for short height.