9781422276143

We also share resemblances with our brothers, sisters, and other family members.

The traits that make us distinct individuals

arise due to the phenomenon of

variation. The branch of biology that deals with studies related to heredity is called genetics.

Reproduction One very important aspect of genetics is the mode of reproduction. There will be no variations between parents and offspring of a rose plant reproduced by cutting (asexual reproduction). However, a tomato plant reproduced by crossbreeding two parent plants (sexual reproduction) will display variations. In asexually reproducing organisms, the offspring is derived from a single parent and hence it is often referred to as monoparental . The offspring in such cases is an exact replica of its parents. Such offspring are known as clones. In plants, each individual clone is referred to as a ramet. Chromosomes Genes are units of heredity; they are transmitted from generation to

generation. They are located in the chromosomes and are made up of DNA (deoxyribonucleic acid), the molecule of inheritance. RNA (ribonucleic acid) also acts as a genetic information carrier in a few viruses where DNA is absent.

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