Heredity and Evolution (part – 1)

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HEREDITY – Transmission of characters from parents to the offspring i.e. from one generation to next generation.

VARIATION – Differences shown by the individuals of a species, and also by the offspring of the same parents are referred to as variations.

GENETICS – Genetics is the branch of biology in which we study about heredity & variation.

DOMINANT TRAIT – A genetic trait is considered dominant if it is expressed in a person who has only one copy of that gene.

RECESSIVE TRAIT – A genetic trait that is expressed only when two copies of the gene are present.

SOMATIC CELL – All cells forming the body of an organism, except the reproductive cells.

GENE – A segment of DNA that is involved in producing a polypeptide chain and forms the basic unit of heredity.

TRAIT –A trait is a distinct variant of a phenotypic character of an organism that may be inherited or environmentally determined.

HAPLOID CELL – Cell having only one set of chromosomes.

DIPLOID CELL – Cell having two sets of chromosomes, one of paternal origin, the other maternal.

GENETIC DRIFT — It refers to the random change in gene frequencies in a small population, presumably owing to chance rather than natural selection, thereby providing diversity without any adaptations.

INHERETED TRAIT – those traits which are controlled by genetic material of the individual and are obtained from the parents in inheritance.

ACQUIRED TRAIT – those trait which acquired by organism during their life period.

ALLELS – is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome.

The transmission of characters (or traits) from the parents to their offspring is called heredity.