Palaeontology : It is the study of fossils or the remains or organisms of past geological age. This includes palaeobotany (dealing with botanical fossils) and palaeozoology (dealing with zoological fossils).Fossils : Fossils are preserved remains of animals, plants or their parts found in the various layers of the earth’s crust or rocks. The word fossil […]

Origin TheoriesSeveral theories regarding the ‘origin of life’ have been put forward.1. Special Creation Theory :According to this theory universe was created by God in six days. This theory has been published in Bible.According to this theory—First day—Earth and heaven were created.Second day—Sky was created.Third day—Dry earth and plants were created.Fourth day—Sun, moon and stars

Man has existed on earth only for the last 50,000 years. It started from stone age some 20,000 years ago. About 6000 years ago the agricultural age started. Industrialization is about 200 years old only. After this the population growth has been very fast.Study of human population statistically is known as demography. Demography as a

Genetics : Genetics deals with the study of of inheritance. Every living organism inherits traits from parents. These traits are transferred from generation to generation. All living being have genetic characters.Bateson in 1905 used for the first time the term ‘Genetics’. Mendel is considered the father of genetics. Genetics was revised in 1900.Genetics can be

GrowthGrowth refers to a process in which size and weight of an organism increases. It is a characterstic of every living being. In the process of growth cells undergo wear and tear process upto maturity. The process of growth is fast. After maturity it becomes a gradual process and finally the organnism dies.Auxetic Growth :

Taxonomy : It deals with the study of the methods of identification, nomenclature and classification of the animals.Adnation : A phenomenon in which organs like leaves, flowers etc. instead of being present at their original place, undergo a shift and are seen away from their original place. Due to this adnation, there is displacement of

Reproductive cycles of femalesAll women have reproduction processess which depends on certain changes in reproductive organs. There are sexual cycles in females.There are two cycles exhibited by mammals specially by woman.Menstrual cycleIn woman menstrual cycle completes in about 26 to 28 days. After these days, ova are released from the ovary about 10 days after

There are two types of skeletal systems in animals.(i) Exoskeleton and (ii) Endoskeleton(i) Exoskeleton : This system is present on the surface of body. Scales in fishes, wings in birds, hair, teeth, horn in mammals are the examples of exoskeleton.(ii) Endoskeleton : It is made of bones and muscles. Man is the well known example.

Motion : All living bodies have the characterstic of movement while non living organisms do not move.Locomotion : Locomotion is defined as walking, swimming, running, crawling, hopping, playing etc. Most of the animals have contractile nature of muscles for movement and locomotion. Every animal has locomotion organs according to his needs.In cellular animals locomotion is

Fertilization : In the process of intercourse, sperm from semen comes in contact with ovum and fertilizes it. After fertilization embryo is formed. It needs proper nutrition and proper care so that the child is normal after growth.Embryonic Nutrition : After the development of an embryo the number of cells increases and the developing embryo

Reproduction is the process by which every animal maintains the existence of its own species. It is a biological process followed by every living organisms.Reproduction is of two types :(A) Asexual reproduction and(B) Sexual Reproduction.(A) Asexual reproduction : In this process the production of animals takes place without fertilization and zygote formation. This is of

Endocrine system contains two types of glands.Exocrine glands : These glands convey their secretion to the place of their action.Endocrine glands : These glands secrete hormones and send them into blood stream. Blood carries these hormones to the place of action. But pancreas and gonads are of mixed nature.Hormones : These are the chemicals produced

Sense organs : Eyes, ears, tongue, nose and skin are the sense organs of the human body. Their description is given below.Eyes : Eyes are the organs of sight. All animals use eyes for seeing the objects. In man these are spherical in shape and situated in the orbits. Each eye ball is made up

Nervous system co-ordinates the functions of different organs of the body. With the help of external stimulus, the system analyses and produces sensations accordingly. It retains the memory of the past. It conducts the messages and information between the different organs of the body. The sense organs like eyes, ears, smell, taste etc. are also

During matabolic activities the harmful waste products produced in the body are eliminated by the body. This is known as excretion. There are several organs such as skin, liver, lungs, large intestine and kidneys, etc. known as excretory organs of the body. These organs help in performing the osmoregulatory function of the body.The animals are