Honozygous female-Ww
Heterozygous male-Ww

In this case, all individuals of F_i,-generation would possess dominant trait. 50% are homozygous dominant and 50% are heterozygous dominant.

Causes of variations in clones.
Clones have the same genetic makeup but variations appear in clones due to following reasons:
(i) Effect of environment termed acquired variations are not inherited.
(ii) Mutations. These are sudden stable abrupt changes and they are discontinuous inheritable as produced due to changes in genetic makeup.
(iii) Identical twins arising from one fertilized egg are clones of each other though they are offspring of their parents and have the same genetic set up.

1. A male honeybee develops parthenogenetically, i.e. from an ovum or female gamete, without fertillisation; hence has no father.
2. A female honeybee develops from the zygote formed by the function of a male and a female gamete; since the mother of a drone has a father, a dron has a grandfather.

1. The characters are controlled by 'Factors' which are stably passed down without any change from the parents to the offspring, through the gametes.
2. The allels do not show any blending.

In the test cross, an individual showing dominant phenotype would be crossed to an individual with recessive phenotype for the same trait.
(i) If the individual is homozygous dominant, all the individuals in the progeny would show the dominant phenotype.

(it) If the individual is heterozygous, the progeny will show dominant phenotype and recessive phenotype in the ratio of 1 : 1.

Thus, the genotype of the individual with dominant phenotype can be ascertained.

Inheritance of flower colour in Antirrhinum majus:

This character shows incomplete dominance , where neither of the two alleles of the gene is completely dominant and the Fl hybrid is intermediate between the two.

(a) 3/4 of the progeny will be black and horned.
(b) 1/4 of the progeny will be red and horned.

Sutton and Boveri noted that the behaviour of chromosomes was parallel to that of genes.
(i) Both genes and chromosomes occur in pairs.
(ii) They segregate during gamete formation and only one member of a pair enters one gamete.
(iii) One pair of genes 'or chromosomes segregates independently of the other pairs.
(iv) Since the number of chromosomes is far less than the number of genes or traits an organism possesses, it is proposed that a number of genes are located on every chromosome.

Dominance:
Every gene contains the information to express a particular trait.
In a diploid organism, there are two alternate forms of a gene, or a pair of alleles.
The two alleles may be similar (homo-zygous) or may be different (heterozygous).
One of them may be different due to some changes that it has undergone, which modify the information of that particular allele.
The phenotype will be dependent on the original unmodified allele.

1. Law of segregation states that the members of the allelic pair that remained together in the parent/hybrid, segregate during gamete formation and enter different gametes.
2.As a result, gametes have only one allele for a trait and are pure for a character,
Parents                : Tall plant  X Dwarf plant 


3. Tall plants: Dwarf plants
3                    1
4. In this case, tallness is dominant and dwarfness is recessive.
5. The \(F_{ 1 }\)  hybrid is tall (dominant character).
6. The recessive character, dwarfness, remains hidden in the \(F_{ 1 }\)  but reappeared in the \(F_{ 2 }\)  generation without any change.
7. This' is because the factors T and t remained together in the hybrid, but segregated during gamete formation and entered different gametes.
 Diploid condition is restored during fertilisation.