Lecture- 17 Numerical Changes in Chromosome

OUTLINE NOTES
गुणसूत्र में संख्या परिवर्तन (Numerical Changes in Chromosome):-

बहुगुणिता (Polyploidy):- 

किसी जीव में सामान्य गुणसूत्र संख्या का विचलित हो जाना ही बहुगुणिता कहलाती है। यह 2 प्रकार की होती है –

(Deviation from the normal chromosome numbers in an organism is called polyploidy. It is of 2 types -)

1. असत्यगुणिता (Aneuploidy):-

   परिभाषा(Definition):- सामान्यतया जीव की प्रत्येक कायिक कोशिका के जीनोम में गुणसूत्रों की संख्या निश्चित होती है। यदि जीनोम में 1 या 2 गुणसूत्रों की संख्या में कमी या वृद्धि हो जाये तो इसे असत्यगुणिता कहते हैं। यह अधिकतर जंतुओं में ही पायी जाती है। पादपों में बहुत कम देखने को मिलती है।

(Generally, the number of chromosomes in the genome of each somatic cell of an organism is fixed. If there is a decrease or increase in the number of 1 or 2 chromosomes in the genome, it is called as aneuploidy. It is found mostly in animals. It is rarely seen in plants.)

   यह 2 प्रकार की होती है (It is of 2 types):-

a. अधोगुणिता (Hypoploidy):- 

i. Nullysomy = (2n – 2):-

- Mutant of Ear in wheat: Dwarf, Female fertile, Male sterile, awn less (तूड़ रहित)

ii. Monosomy = (2n – 1):-

-  Turner Syndrome (44+X0)

iii. Double monosomy = (2n – 1 – 1)

b. अधिगुणिता (Hyperploidy):- 

i. Trisomy = (2n + 1):-

- Klinefelter Syndrome (44+XXY )

- Jacob Syndrome (44+XYY)

- Patau Syndrome (47, 13 double)

- Edward Syndrome (47, 18 double)

- Down Syndrome (47, 21 double)

ii. Double trisomy = (2n + 1 + 1)

iii. Tetrasomy = (2n + 2)

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