Animal hormones are chemical messengers produced by various glands and tissues in animals that...
BIOLOGY
Mammals are biparental in reproduction that is sexual reproduction involves two distinct and separate...
1) Evidence from comparative anatomy Homologous structures can be used to explain the evidence...
A) Mutation theory of organic evolution Mutation is a change in genetic material resulting...
Charles Darwin, a British biologist, in 1859 propounded a theory of organic evolution by...
Jean Baptiste Lamarck, a French biologist was one of the first biologists to put...
The world is occupied by millions of different kinds of plants and animals. These...
The lower plants All the plants from the single-celled Chlamydomonas, bacterium, Phacus to the...
The part of plasma which filters into the spaces among the tissues and flows...
There are three plans or types of blood circulation in human beings, other mammals...
The heart is an muscular organ that pumps blood to all human parts of...
The transport system carries food and oxygen to all tissues and removes waste materials...
The group – Pteridophyta consists of ferns and club-mosses. Dryopteris is a fern. It...
Mosses are small, green and simple land plants belonging to phylum Bryophyta and class...
Seeds A seed is a structure which develops from the ovule after fertilization. A...
After the maturation of fruits, an abscission layer is formed at the point of...
Swimming movements Each side of the vertebral column (flexible backbone) of a fish is...
The appendicular skeleton is made up of the limb girdles (pectoral and pelvic girdles)...
There are over 2,000,000 known different organisms in the world today and probably over...
The animal kingdom is divided into invertebrates (animals without backbones) and vertebrates (animals with...
The modern classification system based on physiology, biochemistry and embryology have revealed distinct similarities...
Cockroach is an omnivorous animal eating anything ranging from starchy and sweet things to...
Movements in Hydra 1) Swaying Sometimes Hydra comes to rest on rock or other...
Haemorrhage (bleeding) is the coming out of blood from the blood vessels which have...
Pollination is defined as the transfer of mature pollen grains from the anthers of...
Immediately after pollination, fertilization follows. Fertilization is the union of male and female gametes...
This is the part of the plant which grows above the soil except the...
The root system is the part of the plant growing in the soil. This...
The flowering plants form a group of plants known as Angiosperms. They are characterized...
Primates are the most highly developed of all mammals with large brain, forward-facing eyes...
The mammalian gametes are male gametes called sperm or spermatozoa (singular = spermato-zoon), while...
Germination is a process by which the embryo of a seed grows out of...
Parturition (labour) is the expulsion of the foetus, placenta and foetal membranes from the...
When the embryo has been implanted, it produces four extraembryonic membranes (membranes outside the...
The liver is the largest gland in the body. It is dark-red, spongy and...
The stomach is a thick-walled large muscular sac which lies in the left portion...
Experiment 1 Aim: To demostrate the action of ptyalin (saliva) on cooked starch. Method:...
Genetic traits are determined by genes located on the chromosomes. The sex of an...
A fracture is any break in a bone. There are two kinds of fracture...
Neurones are specialized cells that transmit impulses (messages) around the body in form of...