Genetics and Evolution

Alimentary Canal in Cockroach

The ancestors of cockroaches originated during the carboniferous period, around 300-500 million years ago, they lacked the internal ovipositors of modern roaches. They have special adaptations which are sucking  Mouthparts like other true bugs are considered to be much more generalised insects. They have chewing mouthparts and the most primitive of living Neopterin insects. Tropical […]

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Biology, Class 12, Evolution: Origin of life, Darwin’s theory, adaptive radiation, Genetics and Evolution, NEET

Adaptive Radiation Evolution

According to Darwin, living organisms adapt themselves to changing environments for the continuation of their survival. The main reason which initiates the process of evolution is the demand of exploitation of a niche but inability to do so because of some structure and physical or anatomical issues. The phenomenon of adaptive radiation was first described

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Biology, Class 12, Evolution: Origin of life, Darwin’s theory, adaptive radiation, Genetics and Evolution, NEET

Adaptive Radiation

Introduction Evolutionary theory holds that living creatures change their physical and anatomical structures over a lengthy period of time in order to make better adaptations to their changing environment. When organisms attempted to exploit a niche but were unable to do so because of their current body design or structural component, this marked the beginning

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Biology, Class 12, Evolution: Origin of life, Darwin’s theory, adaptive radiation, Genetics and Evolution, NEET

ADAPTATION

Adaptation refers to the process of adjusting behaviour, physiology, or structure to become more adapted to a given environment in biology and ecology. It may also be described as the condition attained by a biological population that is experiencing modifications or adjustments. It might also refer to a characteristic that helped the species adapt to

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Biology, Class 12, Evolution: Origin of life, Darwin’s theory, adaptive radiation, Genetics and Evolution, NEET

Point Mutation

A point mutation occurs when one single nucleotide base is added, removed, or modified in DNA or RNA, the genetic material of the organism. Nucleotides are the building blocks of DNA and RNA. Cytosine, guanine, adenine, thymine (in DNA), and uracil (in RNA), abbreviated C, G, A, T, and U, are five distinct compounds that

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Biology, Class 12, Genetics and Evolution, Molecular basis of inheritance: DNA, RNA, replication, transcription, NEET

The Concept of Okazaki Fragments

During DNA replication, Okazaki fragments (which are approximately 150 to 200 base pairs long in eukaryotes) are short sequences of DNA nucleotides that are synthesised in a discontinuous manner and later linked together by the enzyme DNA to form the lagging strand, which is known as the lagging strand syndrome.  Okazaki Fragments When a cell

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Biology, Class 12, Genetics and Evolution, Molecular basis of inheritance: DNA, RNA, replication, transcription, NEET

RNA Splicing

This is true for most eukaryotic genes (as well as some prokaryotic ones). A technique known as RNA splicing is used to remove or “splice out” certain segments known as intervening sequences, or introns, from the RNA molecule during one of the steps in this processing. As a result, the final mRNA is composed of

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Biology, Class 12, Genetics and Evolution, Molecular basis of inheritance: DNA, RNA, replication, transcription, NEET

Genetic material DNA RNA

DNA is the most common type of genetic material, however some viruses, such as retroviruses, also contain RNA. In higher species, RNA is mostly used as a messenger to communicate information. How come their roles are so different, despite the fact that they are both nucleic acids? Because of the differences in the chemical structure

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Biology, Class 12, Genetics and Evolution, Molecular basis of inheritance: DNA, RNA, replication, transcription, NEET

Properties of Genetic Code

Introduction The genetic code is a collection of laws that define how DNA’s four-letter code is converted into a 20-letter code, which serves as the building block of proteins. The genetic code is consist of codons, which are 3 –letters nucleotide pairings that each correspond to a distinct amino acid or stop signal. Francis Crick

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Biology, Class 12, Genetics and Evolution, Molecular basis of inheritance: DNA, RNA, replication, transcription, NEET

Ligases

In this enzyme, the association between the deoxyribose group on one strand of DNA and phosphate group on the other strand of DNA forms a link that joins the two DNA strands together. The Okazaki fragments that form on the lagging strand during DNA replication are joined together by the DNA ligase, which is functional

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Biology, Class 12, Genetics and Evolution, Molecular basis of inheritance: DNA, RNA, replication, transcription, NEET