CLASS 10 SCIENCE - CHAPTER 7 NOTES
HOW DO ORGANISMS REPRODUCE?
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PAGE 1: INTRODUCTION & ASEXUAL REPRODUCTION (FISSION)
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[1.1] REPRODUCTION KYA HAI? (Introduction)
* Definition: Wo biological process jisme parents apne jaise naye organisms
(offsprings) ko janm dete hain, use Reproduction kehte hain.
* Importance: Yeh kisi individual ko zinda rakhne ke liye zaroori nahi hai
(jaise digestion ya respiration hai), par yeh poari earth par kisi species
ki continuity (ashtitva) banaye rakhne ke liye zaroori hai.
[1.2] DNA COPYING KA ROLE
* Cell ke nucleus mein Chromosomes hote hain, jisme DNA (Deoxyribonucleic Acid)
ke roop mein parents se bacchon mein characters transfer hote hain.
* Jab cell reproduce karta hai, toh wo chemical reactions ke zariye apne DNA ki
ek Copy banata hai.
* Variation ka Fayda: DNA copy bilkul exact same nahi hoti, usme thode changes
aate hain jise 'Variation' kehte hain. Yeh variation badalte environment mein
organism ko zinda rehne mein madad karta hai aur isi se Evolution hota hai.
[1.3] TYPES OF REPRODUCTION
1. Asexual Reproduction: Isme sirf ek single parent involve hota hai aur koi
sex cells (gametes) nahi bante.
2. Sexual Reproduction: Isme do parents (Male aur Female) involve hote hain aur
gametes ka fusion hota hai.
[1.4] METHODS OF ASEXUAL REPRODUCTION (FISSION)
* Fission: Ek unicellular organism ka split (toot) kar naye cells banana.
1. Binary Fission: Isme parent cell do barabar hisson mein toot jata hai.
* Example: Amoeba (kisi bhi plane se split ho sakta hai), Leishmania (kala-azar ka
parasite).
2. Multiple Fission: Unfavorable conditions mein ek cell ke andar bohot saare
daughter cells ek saath bante hain.
* Example: Plasmodium (Malaria ka parasite).
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PAGE 2: ASEXUAL REPRODUCTION (OTHER METHODS)
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* Fragment ka matlab hota hai tukda. Simple multicellular organisms mature hone
par chhote pieces mein toot jaate hain, aur har tukda naya organism banata hai.
* Example: Spirogyra.
, * Agar kisi organism ka body part cut jaye, toh wo broken part se pura naya
organism dobara grow kar leta hai. Isme special cells multiply karti hain.
* Example: Hydra aur Planaria.
* Body par ek chhota sa ubhar (outgrowth) nikalta hai jise 'Bud' kehte hain.
Yeh bud bada hokar parent body se alag ho jata hai aur naya organism banta hai.
* Example: Hydra aur Yeast.
* Fungus (jaise bread mould/Rhizopus) ke upar chhote knob-like structures hote hain
jise 'Sporangia' kehte hain. Iske andar 'Spores' hote hain. Jab ye phatata hai,
toh spores hawa mein fail jaate hain aur moist jagah milne par naya fungus ugate hain.
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PAGE 3: VEGETATIVE PROPAGATION (Paudhon mein Asexual)
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* Jab naye plants bina seed (beej) ke, plant ke purane parts jaise Root (jad),
Stem (tana), ya Leaves (patti) se ugaye jaate hain.
* Natural Examples:
1. By Roots: Sweet Potato (Shakarkand).
2. By Stems: Potato (Aloo), Ginger (Adrak).
3. By Leaves: Bryophyllum (patti ke kinaron se naye paudhe nikalte hain).
* Artificial Methods: Layering, Grafting, Cutting (jaise Rose aur Sugarcane mein).
* Advantages (Fayde):
1. Isse raise kiye gaye plants mein phool aur phal jaldi aate hain.
2. Naye plants bilkul parent plant jaise (genetically similar) hote hain.
3. Un plants ko ugane mein madad milti hai jo beej paida karne ki kshamta kho chuke hain
(Banana, Orange).
* Tissue Culture: Plant ke growing tip se cells nikal kar artificial nutrient medium
mein rakhna, jisse ek cell mass 'Callus' banta hai aur naye plants bante hain.
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PAGE 4: SEXUAL REPRODUCTION IN PLANTS (Phoolon mein)
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Flowers paudhon ke reproductive parts hote hain.
[4.1] PARTS OF A FLOWER
1. Sepals: Green rang ki pattiyan jo bud stage mein flower ko protect karti hain.
2. Petals: Color waali pattiyan jo insects ko attract karti hain.
3. Stamen (Male Part): Iske do parts hote hain—Anther (jo Pollen Grains banata hai)
aur Filament.
4. Carpel/Pistil (Female Part): Yeh center mein hota hai. Iske 3 parts hote hain:
* Stigma: Sticky top part jahan pollen grain aakar chipakta hai.
* Style: Ek lambi tube.
HOW DO ORGANISMS REPRODUCE?
======================================================================
==========
--------------------------------------------------------------------------------
PAGE 1: INTRODUCTION & ASEXUAL REPRODUCTION (FISSION)
--------------------------------------------------------------------------------
[1.1] REPRODUCTION KYA HAI? (Introduction)
* Definition: Wo biological process jisme parents apne jaise naye organisms
(offsprings) ko janm dete hain, use Reproduction kehte hain.
* Importance: Yeh kisi individual ko zinda rakhne ke liye zaroori nahi hai
(jaise digestion ya respiration hai), par yeh poari earth par kisi species
ki continuity (ashtitva) banaye rakhne ke liye zaroori hai.
[1.2] DNA COPYING KA ROLE
* Cell ke nucleus mein Chromosomes hote hain, jisme DNA (Deoxyribonucleic Acid)
ke roop mein parents se bacchon mein characters transfer hote hain.
* Jab cell reproduce karta hai, toh wo chemical reactions ke zariye apne DNA ki
ek Copy banata hai.
* Variation ka Fayda: DNA copy bilkul exact same nahi hoti, usme thode changes
aate hain jise 'Variation' kehte hain. Yeh variation badalte environment mein
organism ko zinda rehne mein madad karta hai aur isi se Evolution hota hai.
[1.3] TYPES OF REPRODUCTION
1. Asexual Reproduction: Isme sirf ek single parent involve hota hai aur koi
sex cells (gametes) nahi bante.
2. Sexual Reproduction: Isme do parents (Male aur Female) involve hote hain aur
gametes ka fusion hota hai.
[1.4] METHODS OF ASEXUAL REPRODUCTION (FISSION)
* Fission: Ek unicellular organism ka split (toot) kar naye cells banana.
1. Binary Fission: Isme parent cell do barabar hisson mein toot jata hai.
* Example: Amoeba (kisi bhi plane se split ho sakta hai), Leishmania (kala-azar ka
parasite).
2. Multiple Fission: Unfavorable conditions mein ek cell ke andar bohot saare
daughter cells ek saath bante hain.
* Example: Plasmodium (Malaria ka parasite).
--------------------------------------------------------------------------------
PAGE 2: ASEXUAL REPRODUCTION (OTHER METHODS)
--------------------------------------------------------------------------------
* Fragment ka matlab hota hai tukda. Simple multicellular organisms mature hone
par chhote pieces mein toot jaate hain, aur har tukda naya organism banata hai.
* Example: Spirogyra.
, * Agar kisi organism ka body part cut jaye, toh wo broken part se pura naya
organism dobara grow kar leta hai. Isme special cells multiply karti hain.
* Example: Hydra aur Planaria.
* Body par ek chhota sa ubhar (outgrowth) nikalta hai jise 'Bud' kehte hain.
Yeh bud bada hokar parent body se alag ho jata hai aur naya organism banta hai.
* Example: Hydra aur Yeast.
* Fungus (jaise bread mould/Rhizopus) ke upar chhote knob-like structures hote hain
jise 'Sporangia' kehte hain. Iske andar 'Spores' hote hain. Jab ye phatata hai,
toh spores hawa mein fail jaate hain aur moist jagah milne par naya fungus ugate hain.
--------------------------------------------------------------------------------
PAGE 3: VEGETATIVE PROPAGATION (Paudhon mein Asexual)
--------------------------------------------------------------------------------
* Jab naye plants bina seed (beej) ke, plant ke purane parts jaise Root (jad),
Stem (tana), ya Leaves (patti) se ugaye jaate hain.
* Natural Examples:
1. By Roots: Sweet Potato (Shakarkand).
2. By Stems: Potato (Aloo), Ginger (Adrak).
3. By Leaves: Bryophyllum (patti ke kinaron se naye paudhe nikalte hain).
* Artificial Methods: Layering, Grafting, Cutting (jaise Rose aur Sugarcane mein).
* Advantages (Fayde):
1. Isse raise kiye gaye plants mein phool aur phal jaldi aate hain.
2. Naye plants bilkul parent plant jaise (genetically similar) hote hain.
3. Un plants ko ugane mein madad milti hai jo beej paida karne ki kshamta kho chuke hain
(Banana, Orange).
* Tissue Culture: Plant ke growing tip se cells nikal kar artificial nutrient medium
mein rakhna, jisse ek cell mass 'Callus' banta hai aur naye plants bante hain.
--------------------------------------------------------------------------------
PAGE 4: SEXUAL REPRODUCTION IN PLANTS (Phoolon mein)
--------------------------------------------------------------------------------
Flowers paudhon ke reproductive parts hote hain.
[4.1] PARTS OF A FLOWER
1. Sepals: Green rang ki pattiyan jo bud stage mein flower ko protect karti hain.
2. Petals: Color waali pattiyan jo insects ko attract karti hain.
3. Stamen (Male Part): Iske do parts hote hain—Anther (jo Pollen Grains banata hai)
aur Filament.
4. Carpel/Pistil (Female Part): Yeh center mein hota hai. Iske 3 parts hote hain:
* Stigma: Sticky top part jahan pollen grain aakar chipakta hai.
* Style: Ek lambi tube.
