Animal hormones are chemical messengers produced by various glands and tissues in animals that regulate physiological processes...
BIOLOGY
Mammals are biparental in reproduction that is sexual reproduction involves two distinct and separate individuals, sexually mature...
1) Evidence from comparative anatomy Homologous structures can be used to explain the evidence of comparative anatomy....
A) Mutation theory of organic evolution Mutation is a change in genetic material resulting in a new...
Charles Darwin, a British biologist, in 1859 propounded a theory of organic evolution by Natural Selection leading...
Jean Baptiste Lamarck, a French biologist was one of the first biologists to put forward the theory...
The world is occupied by millions of different kinds of plants and animals. These plants and animals...
The lower plants All the plants from the single-celled Chlamydomonas, bacterium, Phacus to the simple multicellular Spirogyra,...
The part of plasma which filters into the spaces among the tissues and flows in vessels similar...
There are three plans or types of blood circulation in human beings, other mammals and birds. They...
The heart is an muscular organ that pumps blood to all human parts of the body. It...
The transport system carries food and oxygen to all tissues and removes waste materials of metabolism, convenes...
The group – Pteridophyta consists of ferns and club-mosses. Dryopteris is a fern. It is seen growing...
Mosses are small, green and simple land plants belonging to phylum Bryophyta and class Musci. They are...
Seeds A seed is a structure which develops from the ovule after fertilization. A seed consists of...
After the maturation of fruits, an abscission layer is formed at the point of attachment of the...
Swimming movements Each side of the vertebral column (flexible backbone) of a fish is made of muscle...
The appendicular skeleton is made up of the limb girdles (pectoral and pelvic girdles) and the limbs...
There are over 2,000,000 known different organisms in the world today and probably over 1,000,000 are left...
The animal kingdom is divided into invertebrates (animals without backbones) and vertebrates (animals with backbones). Invertebrates...
The modern classification system based on physiology, biochemistry and embryology have revealed distinct similarities between living organisms...
Cockroach is an omnivorous animal eating anything ranging from starchy and sweet things to papers, clothes etc....
Movements in Hydra 1) Swaying Sometimes Hydra comes to rest on rock or other suitable hard surface...
Haemorrhage (bleeding) is the coming out of blood from the blood vessels which have been damaged. When...
Pollination is defined as the transfer of mature pollen grains from the anthers of one flower to...
Immediately after pollination, fertilization follows. Fertilization is the union of male and female gametes to form a...
This is the part of the plant which grows above the soil except the modified aerial roots....
The root system is the part of the plant growing in the soil. This excludes the underground...
The flowering plants form a group of plants known as Angiosperms. They are characterized by the possession...
Primates are the most highly developed of all mammals with large brain, forward-facing eyes with bilocular vision,...
The mammalian gametes are male gametes called sperm or spermatozoa (singular = spermato-zoon), while the female gametes...
Germination is a process by which the embryo of a seed grows out of its testa and...
Parturition (labour) is the expulsion of the foetus, placenta and foetal membranes from the uterus. After about...
When the embryo has been implanted, it produces four extraembryonic membranes (membranes outside the body of the...
The liver is the largest gland in the body. It is dark-red, spongy and lobed. The lobes...
The stomach is a thick-walled large muscular sac which lies in the left portion of the abdominal...
Experiment 1 Aim: To demostrate the action of ptyalin (saliva) on cooked starch. Method: Some saliva is...
Genetic traits are determined by genes located on the chromosomes. The sex of an organism is a...
A fracture is any break in a bone. There are two kinds of fracture namely simple (closed)...
Neurones are specialized cells that transmit impulses (messages) around the body in form of electrical charges. The...
A bone is strong, hard and tough connective tissue mainly made of calcified material. Composition of...
Muscles can be referred to simply as the flesh mostly associated with bones to give shape to...
Transpiration is the loss of water vapour from different parts of the plant shoot. These parts include...
Fish and tadpoles are aquatic vertebrates. They possess gills for gaseous exchange. Gills of fish Fish...
Planaria is a free-living, flat, slender and small worm. The digestive tract consists of a ventrally placed...
This is the response of plant parts to the stimulus of gravity. Plant shoots grow away from...
The eyes are the organs of sight in the higher invertebrates and all vertebrates. They (eyes) are...
There are no special excretory organs or systems in plants. The plants as living things do carry...
The oxygen needed to oxidize lactic acid to pyruvic acid and from pyruvic acid to carbon oxide,...
Translocation is the transport of manufactured food substances from the leaves to all parts of the plant....
