[tex]\underline{\underline{\large{\green{\cal{EXPLANATION:}}}}} [/tex]
Dominance shows interactions between alleles with regard to the phenotypes they produce.
If a dominant allele covers up another one, it will show itself as the dominant allele or trait. This allows its phenotype to be expressed in homozygous and heterozygous forms. The capital letter denotes the dominant allele. The other one is recessive and needs two copies (homozygous) to exhibit its traits. It is denoted by a small letter.
Example:
Pea seed color is controlled by a gene with two alleles: yellow and green. Yellow is the dominant allele, so we represent the alleles as:
Y: Yellow seed
y: green seed
This means that the seed will have a yellow color even if just one copy of the allele is present (heterozygous).
YY: Homozygous dominant, yellow seed
YY: Heterozygous, yellow seed
yy: homozygous recessive, green seed.
When one parent is homozygous dominant (YY) and the other is homozygous recessive (YY), all the offspring are heterozygotic (YY), because each parent gives one allele. So, in this case, all the offspring would express the dominant trait which means 100%.
In an YY cross with yy, generation are heterozygous (YY), because each parent contributed one allele. Thus, all these offspring would express 100% dominance.
Final Answer:
Hence, correct option is D. 100%
