Question

Mendel observed red flowers in $F_1$ when he crossed red and white-flowered plants because of
(a)Dominance
(b)Recessive gene
(c)Law of Independent assortment
(d)Law of Segregation

Answer 1

The red flower appears in the $F_1$ progeny when the red and white-flowered plants are crossed because it is more powerful and has a greater influence over the other.

Complete answer:
When a homozygous red flowering plant (RR) is crossed with another homozygous white floral plant(rr). The progeny $F_1$ displays red flowers since red is the dominant character over white. It is called the law of Dominance. The cross is represented below.
Parent: $Red\quad \quad White\\\ RR\quad *\quad rr\\\$
$F_1$ generation: $Red\\\ RrRr$

Additional Information: -According to the law of dominance, one allele in a gene pair will be dominant over the other allele and it is called the dominant allele. The other allele is called the recessive allele.
-If a gene pair is homozygous for the dominant allele, then the dominant character will get expressed.
-If the gene pair is homozygous for the recessive alleles, then the recessive character will get expressed.
-On the contrary, if both dominant and recessive alleles are present, then the person will be heterozygous for that gene pair. In this case, only the dominant trait will get expressed.
-Another interesting phenomenon is observed when the alleles in a gene pair are heterozygous and both the alleles get fully expressed. This phenomenon is called codominance.


So, the correct answer is ‘Dominance’.

Note: Incomplete dominance (also known as partial dominance, semi-dominance, or intermediate inheritance) occurs when the phenotype of the heterozygous genotype is distinct from and mostly similar to the homozygous genotype phenotypes. For instance, the color of the snapdragon flower is homozygous for either white or red. When the homozygous red flower is crossed with the homozygous white flower, a pink snapdragon flower will be formed. The pink snapdragon is the product of incomplete dominance.