Heritage and Evolution

• The component of the cellular nucleus of living organisms that carries hereditary characters is the nucleolus.
• The process of transfer of physical and mental characters from parents to the progeny is known as heredity.
• The components of the DNA molecule are heredity and hereditary changes.
• Heredity is the transfer of biological characters from one generation to another via genes.
• Gregor Johann Mendel is the pioneer of the modern genetics.
• The reasons behind the sudden changes in the offspring were understood due to the mutational theory of Hugo de Vries in 1901.
• Walter Sutton observed the paired chromosomes in the cells of grasshopper in 1902, which was not known to anyone before.
• Research started in the direction of finding the nature of genetic material when it was proved that genes are carried via chromosomes.
• In 1944, a trio of scientists Oswald Avery, Mclyn McCarty and Colin McLeod proved that except viruses, all living organisms have DNA as genetic material.
• In 1961, the French geneticists Francois Jacob and Jack Monod proposed a model for process of protein synthesis with the help of DNA in bacterial cells.
• The technique of recombinant DNA technology emerged which has vast scope in the field of genetic engineering.
• The science of heredity is useful for diagnosis, treatment and prevention of hereditary disorders, production of hybrid varieties of animals and plants and in industrial processes in which microbes are used.
• Transcription, Translation and Translocation are the three processes in which RNA, the genes present in the form of DNA participate in the functioning of cell and thereby control the structure and functioning of the body.
• Palaeontological evidences of evolution include fossils of various organisms that existed millions of years ago.
• Vestigial organs are degenerated or underdeveloped useless organs of organisms.
• Anatomical evidences of evolution include similarities in structure of bones and joints in organs of different animals.
• Willard Libby has been awarded with Nobel Prize (1960) for the invention of carbon dating method.
• Carbon dating method is based upon the radioactive decay of naturally occurring C-14 and it is developed by Willard Libby.
• Evolution is the progressive development of plants and animals from the ancestors having different structural and functional organization.
• Each of the organs is useful to the organism.
• Various organs in body of organisms include heart, brain, lungs, liver, kidney, etc.
• Morphological evidences of evolution include similarities in structure of mouth, position of eyes, structure of nostrils and ear pinnae, and thickly distributed hairs on body in animals and plants.
• Various fossils include appendix, large intestine, small intestine, and vestigial organs like tail-bone (coccyx), wisdom teeth, and body hairs.
• Structure of bones in human foreleg, patagium of bat, flipper of whale, and hand of ox are similar.
• Information about protein synthesis is stored in the DNA and synthesis of appropriate proteins as per requirement is necessary for body.
• These proteins are synthesized by DNA through the RNA, a process called as ‘Central Dogma’.
• mRNA is produced as per the sequence of nucleotides on DNA.
• Only one of the two strands of DNA is used in the process of mRNA production.
• The sequence of nucleotides in mRNA being produced is always complementary to the DNA strand used for synthesis.
• Besides, there is uracil in RNA instead of thymine of DNA.
• The process of RNA synthesis is called as ‘transcription’.
• The mRNA formed in nucleus comes in cytoplasm, bringing in the coded message from DNA.
• The message on mRNA contains the codes for amino acids.
• The theory of 'Gradual development of living organisms' is accepted as the theory of evolution.
• Some mutations may be minor but some may be considerable.
• The function of the appendix of our digestive system is not known.
• 3.5 billion years ago, life had been non-existent on the Earth.
• Some cells may have shown good growth and some may have perished which could not adjust with the surrounding.
• The extinction of large animals like dinosaurs may be due to changes in the environment.
• Complex compounds like proteins and nucleic acids may have formed over the long period from simple compounds.