BIOLOGY

Animal hormones are chemical messengers produced by various glands and tissues in animals that regulate physiological processes and behaviors. These hormones are secreted into the bloodstream and carried to target ...

Mammals are biparental in reproduction that is sexual reproduction involves two distinct and separate individuals, sexually mature male and female. A) Male reproductive system The male reproductive system in man ...

1) Evidence from comparative anatomy Homologous structures can be used to explain the evidence of comparative anatomy. Homologous structures are those structures which are built in the same common plan ...

A) Mutation theory of organic evolution Mutation is a change in genetic material resulting in a new stable characteristic which can be inherited by offspring. Hugo De Vries, a Dutch ...

Charles Darwin, a British biologist, in 1859 propounded a theory of organic evolution by Natural Selection leading to the origin of species. His theory of natural selection is as follows: ...

Jean Baptiste Lamarck, a French biologist was one of the first biologists to put forward the theory of organic evolution in 1801. His idea of organic evolution was hinged on ...

The world is occupied by millions of different kinds of plants and animals. These plants and animals are adapted to different kinds of habitats and niches. How did these different ...

The lower plants All the plants from the single-celled Chlamydomonas, bacterium, Phacus to the simple multicellular Spirogyra, Funaria (Bryophyta) that lack conducting vessels use their cytoplasm for the movement and ...

The part of plasma which filters into the spaces among the tissues and flows in vessels similar to arteries and veins constitute the lymphatic system. The lymph is clear colourless ...

There are three plans or types of blood circulation in human beings, other mammals and birds. They are the pulmonary circulation, systemic circulation and the coronary circulation. The pulmonary circulation ...