Question

When a true breeding pea plant that produces green seeds is pollinated by a true breeding pea plant that produces yellow seeds, all the $F_1$ plants have yellow seeds. This means that the allele for yellow is

• A. Heterozygous
• B. Dominant
• C. Recessive
• D. Lethal

Answer 1

The correct option is B Dominant

Yellow and green seeds are the phenotypic characters shown by pea plants. On taking consideration of Law of dominance, it can be stated that if yellow colour seeds are found in all plants of $F_1$ generation which shows that yellow seeed allele is dominant over green seed allele.

Dominant expression of any allele can be easily seen in heterozygous plants whereas recessive genes can express only in homozygous conditions.

Lethal alleles are alleles that cause the death of the organism that carries them. They are usually a result of mutations in genes that are essential for growth or development. Lethal alleles may be recessive, dominant, or conditional depending on the gene or genes involved. In the given case, the allele for yellow seeds is not lethal, as neither the hybrid nor the pure-line is killed because of it.