sex-linked inheritance

  The chromosomes present in the diploid cells of the majority of the sexually reproducing animals are of two types: autosomes bearing genes for somatic characters and sex chromosomes bearing genes for sex.  Sex chromosomes also carry some genes for non-sexual characters such as colour blindness and haemophilia.  Such genes which are always associated with … Read more

Medallion Inheritance – Monohybrid and Dihybrid cross

MENDELIAN INHERITENCE Mendelian inheritance is a type of biological inheritance that follows the laws originally proposed by Gregor Mendel in 1865 and 1866 and re-discovered in 1900. These laws were initially very controversial. When Mendel’s theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core … Read more

SEX DETERMINATION

  Whether an animal will become a male, a female, or a hermaphrodite is determined very early in development. Scientists have worked for hundreds of years to understand the sex-determination system. The first major breakthrough in understanding sex determination was the discovery of sex chromosomes in the early 1900s. From meticulous analyses of male and … Read more

VITAMINS

VITAMINS Vitamins are organic compounds which are needed in small quantities to sustain life. We need to take vitamins from food because the human body either does not produce enough of them or none at all. There are two types of vitamins: Fat-soluble vitamins: Fat-soluble vitamins are stored in the fatty tissues of the body … Read more

Bio molecules – structure and function of carbohydrates, proteins and fats.Vitamins and deficiency diseases, Enzymes, Hormones – Plant hormones and growth regulation.Animal hormones and their functions.

BIOMOLECULES There is vast diversity of living organisms. The chemical compositon and metabolic reactions of the organisms appear to be similar. The composition of living tissues and non-living matter also appear to be similar in qualitative analysis.Closer analysis reveals that the relative abundance of carbon, hydrogen and oxygen is higher in living system.  All forms … Read more

Structure and function of animal cell and cell organelles

  Objects having characteristics of cellular organization, growth, reproduction, ability to sense environment and give response are living organisms. There are some important features of living organisms: It should grow, which means its structure changes as time goes by in an advantageous manner. It should show adaptation to the environment. It should maintain some balanced … Read more

DNA Structure & Function, DNAReplication,

DNA: STRUCTURE   DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the … Read more

Gene Regulation

GENE REGULATION Gene regulation is the informal term used to describe any mechanism used by a cell to increase or decrease the production of specific gene products (protein or RNA). Cells can modify their gene expression patterns to trigger developmental pathways, respond to environmental stimuli, or adapt to new food sources. All points of gene … Read more

Food web and Food chain

FOOD CHAIN- A food chain starts with producers and ends with top carnivores. The sequence of eaten and being eaten, produces transfer of food energy and it is known as food chain. Grazing food chain-The consumers which start the food chain, utilising the plant or plant part as their food, constitute the grazing food chain. … Read more

Plants and mankind, characteristics of plants, structure and function of plant cells and organelles;

  Objects having characteristics of cellular organization, growth, reproduction, ability to sense environment and give response are living organisms. There are some important features of living organisms: It should grow, which means its structure changes as time goes by in an advantageous manner. It should show adaptation to the environment. It should maintain some balanced … Read more