Principles of Inheritance and Variation Free PDF Download
FAQs on NCERT Books Free Download for Class 12 Biology Chapter 5 - Principles of Inheritance and Variation
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The Chapter 5 of Class 12 Biology is Principle Of Inheritance and Variation. The NCERT Book for Class 12 Biology Chapter 5 is available on Vedantu. Also, the NCERT Solutions of this chapter are provided by Vedantu in the form of a PDF file. Students can easily download this PDF file for free of cost from Vedantu’s website and mobile app if they want to study offline. The skilled teachers prepare the content like the NCERT questions and solutions for the NCERT Book. The language used in this book is easy to understand.
2. Point out some differences between genes and alleles.
The differences between gene and allele are discussed below:
Gene
The part of the DNA structure which passes the necessary information for reproduction and survival is known as a gene.
It is responsible for determining traits in humans
There are many alleles in a gene.
Example - eye color, skin color, hair color, etc.
Allele
The different variants of the gene are called alleles.
They define various features for a particular trait.
In the human body, there is a pair of alleles for a particular gene.
Example - hair color like brown or black
3. Define the following terms:
Co-dominance
Dominance
(1) Co-dominance - The phenomenon in which two genes of equal dominance are taken together and are equally expressed is known as co-dominance.
Example - The blood group alleles IA and IB are dominant over IO. These alleles are taken together and are equally expressed to form the phenotype AB.
(2) Dominance - It is defined as the phenomenon in an individual in which one allelic form of a gene is expressed to the exclusion of the other allelic form.
Example - In the cross-breeding of the tall and short pea plant, the tall character is dominant over the dwarf character in the F1 generation.
4. What are the advantages of selecting the pea plant in Mendel's experiment?
The benefits of selecting the pea plant for Mendel's experiment are as follows:
The availability of many varieties of pea plants as alternative forms for a trait can be seen.
There is a phenomenon of self-pollination in peas.
Pea plants are easily available.
They always show true-breeding as pure lines can be seen for experimental purposes.
They can produce a large number of offspring.
The life cycle of pea is short.
It can be easily grown as it requires care at the time of pollination only.
5. Differentiate between the homozygous and heterozygous individuals.
The difference between the two are: Homozygous Individual
It is a genetic condition in which an individual inherits the same alleles of a gene from both parents.
The two different phenotypes are dominant and recessive.
The result of a homozygous genotype is a single type of gamete.
There is no phenomenon of hybrid vigor in homozygous conditions.
Heterozygous Individual
An individual inherits different alleles of a gene from both parents in a heterozygous condition.
There is only a dominant phenotype.
The result of a heterozygous genotype is two different types of gametes.
There is a phenomenon of hybrid vigor in heterozygous conditions.