SCIENCE AND AGRO STUDIES

Mutation:- •       Definition :-  When there is an accidental and heritable change in a character of a plant, it is called mutation. •      This occurs due to 2 reasons - i.   Change in structure of g ene ii.   Chromosomal aberrations •       Word   “Mutation”:-   Word "Mutation" was given by Hugo de Vries in 1910. •       Discovery :-   The mutation was discovered by T. H. Morgan in 1910 when he observe the White Eye mutant of Drosophila. Characteristics:- •        Mutated alleles are recessive. •       Mutation is a random event. •       It d epends on coincidence. •       Most mutations are harmful. But only 0.1% mutations are beneficial which can be used in plant breeding. Types :- i.   Spontaneous mutation :- Ø    In nature, spontaneous mutations occur automatically. Ø    Di...

OUTLINE NOTES उत्परिवर्तनजन  (Mutagens):- •        परिभाषा  (Definition) :-  ऐसे   भौतिक   या   रासायनिक   कारक   जो   उत्परिवर्तन   को   प्रेरित   करते   हैं ,  उत्परिवर्तनजन   कहलाते   हैं। ( Physical or chemical factors that induce mutation are called mutagens. ) •        प्रकार (Types) :-  उत्परिवर्तनजन 2 प्रकार के होते हैं - ( There are 2 types of mutagens - ) a.  भौतिक   उत्परिवर्तनजन   (Physical mutagens):-  ये  2 प्रकार के होते हैं - ( These are of 2 types - ) i.  आयन कारी   विकिरण  (Ionizing radiations) :-  जो   परमाणुओं   को   धनयनों   या   ऋणायनों   में   परिवर्तित   कर   देते   हैं। ये क्रियाकारी आयन क्षार व शर्करा को क्षति पहुँचते हैं। ( Which convert atoms into cations or anions. These reactive ions damage the bases and sugars. ) उदाहरण ...