KPSC KAS Prelims and Mains Exam
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
HUMAN EVOLUTION Human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years. One of the earliest defining human traits, bipedalism — the ability … Read more
MOLECULAR BASIS OF DIFFERENTIATION Whenever growth occurs, increase in mass, weight etc. takes place. Number of cells increases due to cell division. Sometimes, cells grow in size and they do not divide and lead to growth. The simple multiplication of cells would produce masses of cells but not an organism. Knowledge of developmental processes as … Read more
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
PROTEIN SYNTHESIS Proteins are the end product of many metabolic processes. A typical cell requires thousands of different protein molecules at any given moment. So, the protein requirements of a particular cell has to be satisfied by synthesizing them at site or has to be transferred from where it is being synthesized. This is in … Read more
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
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
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
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
CELL REPRODUCTION Cell reproduction is the process by which cells divide to form new cells. Each time a cell divides, it makes a copy of all of its chromosomes, which are tightly coiled strands of DNA, the genetic material that holds the instructions for all life, and sends an identical copy to the new cell … Read more