Heredity and Evolution-Chapter-9-Notes

Heredity:Transmission of characters (resembles as well as variations) from parents to the off springs, i.e., from one generation to the next generation is called heredity.

Mendel’s Monohybrid Cross

A breeding experiment dealing with a single character is called a monohybrid cross.

Mendel’s Dihybrid Cross

A breeding experiment dealing with two characters at the same time is called a dihybrid cross.

Differences between Inherited and Acquired Traits

Inherited TraitsAcquired Traits
1. These are obtained from the parents.1. These are developed during the life of an individual.
2. These are genetic variations.2. These are somatic variations.
3. These develop due to crossing over phenomenon and mutations.3. These develop due to use and disuse off organs and 
4. These are passed on from one generation to the other.4. These die with the death of the individual.

Differences between Homologous Organs and Analogous Organs

Homologous OrgansAnalogous Organs
1. These generally look different externally.1. These generally look similar externally.
2. These generally perform different functions.2. These perform similar function.
3. These are similar in basic plan and origin.3. They are different in basic plan and origin.
4. These depict divergent evolution or adaptive radiations.4. They show convergent evolution.

Differences between artificial selection and natural selection.

Artificial selectionNatural selection
1. It is an artificial process.1. It is a natural phenomenon.
2. It is controlled by man on a limited scale in specific laboratories.2. It is conducted by nature on a vast scale all over the world.
3. Traits selected for improvement are beneficial to man.3. Traits selected for evolution are beneficial to the species.
4. Results are achieved in a short period.4. Results are achieved over a long period of time.

Q1. Define Evolution?

Q2. What is Heridity?

Q3. Differences between artificial selection and natural selection

3 thoughts on “Heredity and Evolution-Chapter-9-Notes”

  1. 3.Artificial selection
    It is an artificial process.
    Traits selected for improvement are beneficial to man.
    Results are achieve in short time.
    Natural Selection
    It is a natural phenomenon.
    Traits selected for evolution are beneficial to the species.
    Results are achieve over a long period of time.

    Reply

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