Biology 42

From basic fundamentals to complex theories,a broad spectrum of Biology related information has been covered here
Nuclear Chromatin

Introduction :   It is a clearly stained, network of long and fine threads (called chromatin fibers) suspended in nucleoplasm largely in the interphase nucleus. W. Flemming (1879) first discovered by during cell division, these chromatin fibers condense by spiralization and dehydration into number of rods called chromosomes (Waldayer (1888)  DNA is main genetic component of […]

January 23, 20182065 https://chemistrylearning.com/nuclear-chromatin/
Types of DNA

Definition :     There are five – different types of DNA exist in nature, which differs from each other with a difference in the normal state, molecular difference etc.   Types of DNA : (a)        A – DNA  Found at relative humidity 75%. In high salt concentration or ions concentrations like Na+, K+, Cs+ or in […]

January 23, 201811687 https://chemistrylearning.com/types-of-dna/
Denaturation of DNA

Denaturation of DNA Definition :   Denaturation is the transition from native to the denatured state of DNA. Introduction :    Denatured Macromolecule results by disrupted state, or coiled conformation while when same molecule present in ordered state/originally present molecular structure in nature called as native. Denaturation is the transition from Native to Denatured state. When […]

January 23, 20182355 https://chemistrylearning.com/denaturation-of-dna/
Watson and Crick Model

Introduction : James Watson and Francis Crick a rounded with Nobel Prize for (discovering) DNA structure (1953). X – rays diffraction studies indicated that distances between two paired nucleotides is 3.4 A0 and each turn of the double helix (3600) contains 10 paired nucleotides. Postulates of Watson and Crick’s DNA model : DNA exists as […]

January 23, 201810606 https://chemistrylearning.com/watson-and-crick-model/
Chargaff Rule

Introduction : Chargaff Rule of base equivalence was established by Erwin Chargaff. It states that when DNA  from any particular species is subjected to chemical hydrolysis in order to release its component purines  and pyrimidines       (1)  The total amount of adenine released is equal to the total amount of thymine and similarly, […]

December 30, 201713439 https://chemistrylearning.com/chargaff-rule/
Structure of DNA

Definition : DNA is a senetic material (heritable material) responsible for inheritance. Introduction : Chromosomes are made up of basic proteins and nucleic acids. Nucleic acids discovered by Friedrich Miescher in 1869 ( from nuclei of pus cells) DNA is found in the nucleus as well as cytoplasm. It is the storehouse of genetic material. […]

December 30, 20174942 https://chemistrylearning.com/structure-of-dna/
Gene

Definition: A gene is a functional unit attached to the chromosomal thread that can pass from one cell to another and can be transmitted from one generation to another without any change in its chemical and physical nature. Introduction: A Gene is a hereditary unit  (also called hereditary factors of Mendel) and is responsible for […]

December 30, 20171586 https://chemistrylearning.com/gene/
Incomplete Dominance

Definition :     When the genes of an allelomorphic pair are not expressed as dominant/ recessive but in the hybrid. This phenomenon is called Incomplete dominance. Introduction : The law of dominance is not always found to occur, as there are many examples, where dominance is about viz.  (incomplete dominance). In such cases, some characters of […]

December 30, 20171829 https://chemistrylearning.com/incomplete-dominance/
Independent Assortment

Definition : If inheritance of more than one pairs of characters (two or more) is studied simultaneously, the factors (or genes) for each pair of character as sort out independently of other pairs. Introduction :            Whereas the law of segregation applies to the behavior of a single pair of genes, the law of  Independent assortment […]

December 30, 20171614 https://chemistrylearning.com/independent-assortment/
Law of Segregation

Law of Segregation ( Genes are Distributed without mixing ) Definition : During fertilization, two members of allelic pair remain together without mixing and these allele pairs separate or segregate, during gamete formation.   Introduction : When a pair of contrasting characters or yellow/green factors as in fig. are brought together such as allele pair remain […]

December 30, 20174136 https://chemistrylearning.com/law-of-segregation/
Law of Dominance

Definition : When two homozygous individuals with one or more sets of contrasting characters are crossed, the characters that appear in F1 hybrid are dominant characters and those that don’t appear in F1 are recessive. Introduction :                       O Out of two contrasting characters, only one express itself in an individual. […]

December 29, 20174288 https://chemistrylearning.com/law-of-dominance/
Principles of Inheritance & Variation

Mendel’s Experiment : Definition :  Gregor Johann Mendel performed experiments with pea plant and discovered the fundamental laws of inheritance.   Introduction :            Mendel’s discovery was based on precise quantitation of experimental crosses and exceptional abstract thinking. He studied crosses between peas (Pisum sativum) that had paws of contrasting characters. Mendel chose garden pea (Pisum […]

December 29, 20172545 https://chemistrylearning.com/principles-of-inheritance-variation/
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