evolutionary biology

The common features show that an evolutionary process exists and there is a link between the different grou..

The common features show that an evolutionary process exists and there is a link between the different group..

Haeckel (1834-1919) formulated that 'ontogeny recapitulates phylogeny'. This means that the developmental stages that an organism goes through repeat the evolutionary history of the group to which the organism belong..

Animals exhibit a complex body organisation which shows a very clear evolutionary trend. The complexity of animal organisation is seen with reference to features like cellularity, germ layers in the body wall, symmetry of the body parts and the nature of body cavi..

Animals exhibit a complex body organisation which shows a very clear evolutionary trend. The complexity of animal organisation is seen with reference to features like cellularity, germ layers in the body wall, symmetry of the body parts and the nature of body cavit..

Variation may be defined as differences among individuals of a species. All around us we see different organisms belonging to different species. Within each species too, no two individuals are identical to each other. Asexual reproduction produces identical offspring called clones and identical twi..

Variation - Variation may be defined as differences among individuals of a species. All around us we see different organisms belonging to different species. Within each species too, no two individuals are identical to each other. Asexual reproduction produces identical offspring called clones and i..

Animals can be broadly distinguished into two major groups the nonchordates (or invertebrates) and the chordates.Invertebrates account for more than 95% of the animal species that have been identified. These are animals which do not have a vertebral column or a back bone. They are distributed into ..

Introduction - Animals can be broadly distinguished into two major groups the nonchordates (or invertebrates) and the chordates.Invertebrates account for more than 95% of the animal species that have been identified. These are animals which do not have a vertebral column or a back bone. They are di..

is also called the voice box . The vocal cords stretch across the larynx and vibrate when the air passes through them. This vibration produces various sounds. The respiratory tract also helps in the production of sound. The portion of the tract that carries out this function is the larynx or the..