Prabin Kalikote

In humans, the gene of black skin color gene (B) is dominant over the gene of white color (b). Study the given pedigree chart and answer the following questions:

a.   Write down the genotype and phenotype of mother.
- Genotype: bb
   - Phenotype: Pure white
b.   What is the phenotypic and genotype ratio of black and white complexion in F₂generation.
- Phenotype: 2:2 or 1:1
- Genotype: 2:2 or 1:1

What is meant by genetic variation? State the factors that bring out genetic variations.

The structural differences that provide individuality to each member of a species is called variation.
The factors that bring out genetic variation are:
- Structural and functional differences of a gene.
- Environmental factors like food, light, temperature, etc.

State the significance of Mendelism.

The significance of Mendelism are
- Diseases resistant and high yielding varieties of plants and animals can be produced by application of Mendelism.
- Hybrids with desired characteristics can be produced.
- The genotypes and phenotypes likely to be produced in successive generations can be predicted before the cross is made.
- Dominant...

For mice black (B) is dominant phenotype and white (b) is recessive. In certain experiment, a black male mouse of genotype Bb is crossed with a white female of genotype bb....

Here,

Here,
Bb is a black mice because B is dominant character and bb is a pure white mice.
So,
Total black mice (Bb) = 2
And total white mice (bb) = 2
So, phenotype ratio = 2 : 2
...

Draw a phylogenetic chart to show the result in 1st and 2nd filial generation after crossing a round seeded tall pea plant with a wrinkled seed seeded pea plant.

A tall (T) per plant and a dwarf (t) pea plant were first cross pollinated and then self pollinated. The given table shows the result of the experiment. Answer the following questions with the help...

a. Which filial generation does this result belongs to?
- This result belongs to 2nd filial generation.
b. What is the percentage of pea plant having hybrid characteristics?
- 50 percentage of pea plant have hybrid characteristics.
c. Which pair of genes indicate pure tall plant?
- (IT) indicates pure tall pea plant.

Differentiate between mutation and variation.

The difference between mutation and variation are:

Mutation	Variation
A sudden heritable change in the genetic material of an organism is called mutation.	The structural difference that provides individuality to each member of a species is called variation.
Various factors like uv rays, x-rays, etc. are responsible for mutation.	Structural and functional difference of gene, environment factors are responsible for variation.
It is rarely seen due to genetical...

Does Mendel's law apply the human beings too? State any two difficulties Mendel would have faced if he had carried out his experiment on human beings instead of pea plants?

Yes, Mendel's law applies the human beings also.
Any two difficulties that Mendel would have faced if he had carried his experiments on human beings instead of pea plants are:
- Human beings have long term life cycle. It is impossible to observe many generations.
- It is impossible to cross between siblings.
- Human being have many contrasting characters which makes...

what is dihybrid cross? Give one example.

Dihybrid cross is the cross in which to pairs of constracting characteristics are taken into consideration.
For example: Cross between red-flowered tall pea plant and white flowered dwarf pea plant.

State and explain the law of segregation with one example.

Law of segregation states that, "The hybrid obtained in F₁ generation contains two contrasting characteristics of dominant and ressive in nature. Those characteristics remain together for long time in hybrids but don't mix with each other and separates at the time of gametes gets only a pure characteristics."
The monohybrid cross between a pure red flowered pea plant and pure white flowered pea plant up to the 2nd filial generation. In F₁ generation all pea...

State and explain the Mendel's law of dominance?

Mendel's law of dominance states that, "In a crossing between pure organism for constrasting characteristics of a pair, only one characteristics of a pair appears in the first filial generation.
Let us consider a pure tall pea plants (TT) and a pure dwarf pea plant (tt). When a pure tall pea plant is cross pollinated with the pure dwarf one, all the off springs will be tall in first filial generation. Here, tallness appears...

Differentiate between:a.    Genotype and Phenotype.b.    Dominant characteristics and Recessive characteristics.c.    F1 generations and ...

a. Genotype and Phenotype.

Genotype	Phenotype
The internal genetic makeup or appearance of an organism is called genotype.	The external appearance of an organism for a contrasting characteristic is called phenotype.
Parental characteristics can be found in genotype.	Parental characteristics cannot be found 100% in phenotype.
It is expressed in letters.	It is expressed in words.

b. Dominant characteristics and Recessive characteristics.

...

What did Mendel selected pea plant for his study? Give your reasons.

Mendel selected pea plant for his study because of following reasons:
- Pea plant can be cultivated easily and have a short life cycle.
- Breeding controlled easily.
- Pea plant produce large number of off springs after fertilization.
- The flower of pea plants are adequate in size and easy to handle.
...

What are hybrid? How are hybrid produced?

The organism produced after cross fertilization between two genetically different organisms is called hybrids.
Hybrids are produced by crossing between organisms having two contrasting characteristics. This process is called hybridization.

Define heterozygous.

When two alleles of a particular gene are not identical, it is called heterozygous.

Define homozygous.

When the both alleles of a particular gene are identical, it is called homozygous.

Define allelomorph.

Allelomorph is one of a gene or pair of matching genes. It contains a pair of identical alleles.

What are genes? Write short note on gene concept?

The tiny units of heredity located in the chromosomes is called genes.
The concept of 'gene' was introduced by sulten and the term 'gene' was introduced by Johannsom. It is located in chrosomes and arranged in linear fashion. It determine the physical, anatomical and physiological characteristics of organism. These characteristics are transmitted from one generation to other.

What's heredity? What are heredity characteristics? Give two examples.

Heredity is the phenomenon by which Living organisms transmit parental characteristics to their off springs.
Heredity characteristics are the characteristics of the parents which are transmitted to their off springs.
Any too examples are:
- Type of hair in Human beings.
- Color of the eyes.

What is genetics? Who is considered as father of genetics? Why?

The branch of biological science of inheritance which deals with the study of heredity and variation is called genetics. Gregor Johann Mendel is considered as father of genetics because the first scientific study of genetics was carried by him and introduced the concept of genes as the basic unit of heredity.