Chapter 7: How do Organisms Reproduce?
Explore the fundamental mechanisms of life propagation—from cell division copies and asexual cloning to sexual cycles in plants and human biology. Life propagation के basic mechanisms को explore करें—cell division copies और asexual cloning से लेकर plants के sexual cycles और human biology तक।
- In Class 9, we learned that mitosis cell division leads to growth, while meiosis reduction division yields gametes. Class 9 mein, हमने सीखा था ki mitosis cell division से growth होती है, jabki meiosis reduction division से gametes (युग्मक) bante hain.
- Chromosomes in the cell nucleus contain DNA molecules, which are the blueprints of heredity. Cell nucleus के chromosomes (गुणसूत्र) mein DNA (Deoxyribonucleic Acid) molecules होते हैं, जो heredity (heredity) के blueprints होते हैं.
- Reproduction is not essential to keep an individual organism alive (unlike respiration or nutrition), but is required to keep a species alive. किसी individual organism को ज़िंदा रखने के लिए reproduction ज़रूरी नहीं है (respiration या nutrition की तरह), पर species को ज़िंदा रखने के लिए यह ज़रूरी है।
1. DNA Copying & Variation
Imagine copying a recipe book by hand. Most of the copies will be exactly the same. However, occasionally, you will make a spelling mistake (variation). If a new ingredient is introduced, one of those spelling mistakes might turn out to make the food taste better! DNA copying is that copy machine, and variations are those accidental spelling mistakes. मान लीजिए आप हाथ से एक recipe book copy कर रहे हैं। Mostly copies बिल्कुल same होंगी। लेकिन कभी-कभी, आप से spelling mistake (variation) हो सकती है। अगर कोई नया ingredient introduce होता है, तो उन spelling mistakes में से एक और बेहतर taste दे सकती है! DNA copying वही copy machine है, और variations वो accidental spelling mistakes हैं।
Reproduction at its most basic level involves creating copies of the blueprints of body design [NCERT p.99]. The chromosomes in the nucleus of a cell contain information for inheritance of features in the form of DNA (Deoxyribonucleic Acid) molecules [NCERT p.99]. Reproduction के basic level पर body design के blueprints ki copies banana involve होता है [NCERT p.99]। Cell के nucleus mein present chromosomes में DNA (Deoxyribonucleic Acid) molecules के roop mein features ki inheritance ki information होती है [NCERT p.99]।
Therefore, the basic event in reproduction is the creation of a DNA copy [NCERT p.99]. Cells use chemical reactions to make copies of their DNA. Along with the DNA copy, the cell creates additional cellular machinery (cytoplasm, organelles) so that when the cell divides by karyokinesis and cytokinesis, each daughter cell has its own active DNA and metabolic system [NCERT p.99].
No bio-chemical copying reaction is 100% accurate. Therefore, the copying process will always result in minor deviations. These errors lead to variations among the offspring cells [NCERT p.99]. कोई भी bio-chemical copying reaction 100% accurate nahi होती. Isliye, copying process के dauran हमेशा थोड़े changes आते हैं. ये errors offspring cells के बीच variations (विविधताएं) create karte hain [NCERT p.99]।
The Biological Importance of Variation: The Biological Importance of Variation (विविधता का जैविक महत्व):
Niches in the ecosystem can change drastically due to temperature shifts (global warming), water level fluctuations, or meteorite impacts [NCERT p.99]. If a population of reproducing organisms were suited to a specific niche and that niche were altered, the entire population could be wiped out [NCERT p.99]. Ecosystem के niches mein temperature shifts (global warming), water level fluctuations, या meteorite impacts ki wajah से बड़े badlaav aa सकते हैं [NCERT p.99]। अगर reproducing organisms ki population किसी specific नीचे के लिए suited हो और वह नीचे badal jaye, तो poori population khatam हो सकती है [NCERT p.99]।
However, if some variations are present in a few individuals, they might survive.
Example: In a population of temperate water bacteria, if the water temperature rises due to global warming, most will die. But a few heat-resistant variants will survive and multiply, ensuring the survival of the species [NCERT p.99]. Thus, variation is useful for the survival of species over time [NCERT p.99].
Rotate the 3D DNA model by dragging it and adjust the slider to unzip the double helix. Watch how matching complementary bases (A-T, G-C) form two identical DNA molecules during replication. 3D DNA model को drag karke rotate करें और double helix को unzip करने के लिए slider adjust करें। Dekhein kaise matching complementary bases (a-t, g-c) replication के dauran do identical DNA molecules banate हैं।
- DNA replication in the cell nucleus is the fundamental biochemical event of reproduction. Cell nucleus में DNA replication, reproduction का fundamental biochemical event है।
- Errors in DNA copying lead to genetic variations, meaning offspring are not identical copies. DNA copying में होने वाली errors, genetic variations create करती हैं, जिससे offspring, parent के बिल्कुल identical copies नहीं होते।
- Variation allows species to adapt and survive environmental disruptions like temperature or water changes. Variation, species को temperature या water level change जैसे environmental changes के according adjust करने और survive करने में help करती है।
2. Modes of Asexual Reproduction 2. Modes of Asexual Reproduction (अलैंगिक reproduction के तरीके)
Asexual reproduction is like a single parent cutting pieces of itself to make identical clone soldiers. There are no partners or gametes. The offspring are genetic copies (clones) of the single parent, and propagation is rapid. Asexual reproduction ek single parent के khud के pieces karke identical clone soldiers करने jaisa है। Isme कोई partners या gametes nahi होते। Offspring single parent ki genetic copies (clones) होते हैं, और propagation bahut fast होता है।
In asexual reproduction, a single parent creates offspring without the fusion of male and female gametes.
Key Asexual Mechanisms: Key Asexual Mechanisms (मुख्य अलैंगिक तरीके):
1. Fission (खंडन) 1. Fission (विखंडन / खंडन)
- Binary Fission: The parent cell splits into two equal halves. In Amoeba, this splitting can occur in any plane [NCERT p.100]. In Leishmania (which causes kala-azar), fission occurs in a definite longitudinal orientation relative to its whip-like flagella [NCERT p.100]. Binary Fission: Parent cell do equal halves mein split होती है। Amoeba mein ये splitting किसी भी plane mein हो सकती है [NCERT p.100]। Leishmania (जो kala-azar failata है) mein, fission flagella के relative ek definite longitudinal plane mein होता है [NCERT p.100]।
- Multiple Fission: The cell divides into many daughter cells simultaneously, as seen in the malaria parasite Plasmodium [NCERT p.100]. Multiple Fission: Cell ek sath kai daughter cells mein divide होती है, जैसे malaria parasite Plasmodium mein देखा jata है [NCERT p.100]।
2. Fragmentation (खंडीभवन) 2. Fragmentation (खंडीभवन)
In simple multicellular organisms like the alga Spirogyra, the body breaks up into smaller pieces (fragments) upon maturation. These fragments grow into new individuals [NCERT p.100]. Simple multicellular organisms जैसे alga Spirogyra mein, mature hone पर body छोटे-छोटे pieces (fragments) mein toot jati है। ये fragments naye individuals mein grow कर jate हैं [NCERT p.100]।
3. Regeneration (पुनरुद्भवन) 3. Regeneration (पुनरुद्भवन)
If simple organisms like Planaria or Hydra are cut into pieces, many of these pieces grow into complete separate individuals [NCERT p.100]. This is carried out by specialized regenerative cells that divide rapidly to form mass cell clusters [NCERT p.101].
Note: Regeneration is not the same as reproduction, since normal organisms do not wait to be cut up to reproduce [NCERT p.101].
4. Budding (मुकुलन) 4. Budding (मुकुलन)
In Hydra, a bud develops as an outgrowth due to repeated cell division at one specific site. This bud grows, develops tiny tentacles, and once fully mature, detaches from the parent body to live independently [NCERT p.101]. Yeast also reproduces via budding. Hydra mein, ek specific site पर repeated cell division के karan ek bud outgrowth के roop mein develop होता है। ये bud grow करता है, छोटी-छोटी tentacles बनता है, और mature hone पर parent body से alag hokar independent life jeeta है [NCERT p.101]। Yeast भी budding के द्वारा reproduce करता है।
5. Vegetative Propagation (कायिक प्रवर्धन) 5. Vegetative Propagation (कायिक प्रवर्धन)
New plants are developed from vegetative parts like roots, stems, or leaves [NCERT p.101]. Naye plants vegetative parts जैसे roots, stems, या leaves से develop किए जाते हैं [NCERT p.101]।
- In Bryophyllum (पत्थरचट्टा), buds develop in the notches along the leaf margins. If the leaf falls on moist soil, these buds grow into new plantlets [NCERT p.102]. Bryophyllum (पत्थरचट्टा) mein, leaf margins ki notches par buds develop hoti hain। Agar ye leaf moist soil par girti hai, toh ye buds naye plantlets mein grow kar jati hain [NCERT p.102]।
- Advantages: Plants raised this way bear flowers and fruits earlier than those grown from seeds. It allows propagation of seedless plants (banana, orange, rose). All plants are genetically identical to the parent [NCERT p.102]. Advantages: Is tareeqe से ugaye गए plants seeds वाले plants के comparison mein flowers और fruits jaldi bear करते हैं। ये seedless plants (banana, orange, rose) के propagation mein help करता है। सभी plants parent plant के genetically identical होते हैं [NCERT p.102]।
6. Spore Formation (बीजाणु समासंघ) 6. Spore Formation (बीजाणु समासंघ)
In the bread mould fungus Rhizopus, thread-like hyphae grow tiny blobs-on-sticks called sporangia [NCERT p.103]. Sporangia contain tiny reproductive cells called spores, which are protected by thick walls that resist dry conditions. When they land on moist bread, they germinate [NCERT p.103]. Bread mould fungus Rhizopus mein, thread-like hyphae पर tiny blobs-on-sticks develop होते हैं jinhein sporangia (बीजाणुधानी) kehte hain [NCERT p.103]। Sporangia के अंदर tiny reproductive cells होती हैं jinhein spores (बीजाणु) kehte hain, jo dry conditions ko resist karne wali thick walls se protected hote hain। Jab ye moist bread par girti hain, toh germinate ho jati hain [NCERT p.103]।
Select a reproduction mode and drag the slider to watch cell division and regeneration happen step-by-step. Ek reproduction mode select करें और cell division और regeneration को step-by-step dekhne के लिए slider drag करें।
- Fission divides single cells equally (Amoeba) or into multiple cells (Plasmodium). Fission, cell को दो बराबर daughter cells में divide करता है (Amoeba) या multiple cells में (Plasmodium)।
- Simple multicellular organisms use fragmentation (Spirogyra) or regeneration from cut pieces (Planaria). Simple multicellular organisms, fragmentation use करते हैं (Spirogyra) या cut pieces से grow करने के लिए regeneration (Planaria)।
- Vegetative propagation allows seedless plants to grow from vegetative parts like Bryophyllum leaves. Vegetative propagation से seedless plants को उनके vegetative parts (जैसे Bryophyllum की leaves) के through उगाया जा सकता है।
3. Sexual Reproduction in Flowering Plants 3. Sexual Reproduction in Flowering Plants (पुष्पी पादपों में लैंगिक reproduction)
Pollen grains are parcels containing male blueprints, and the flower stigma is the delivery address. Bees, wind, and water are postmen carrying these pollen parcels (pollination). Once delivered, the pollen grows a long delivery tube styled downward to the ovary vault, fusing with the egg cell (fertilization) to create a seed. Pollen grains parcels हैं jinme male blueprints होते हैं, और flower का stigma delivery address है। Bees, wind, और water un postmen ki तरह हैं जो इन pollen parcels को carry करते हैं (pollination)। Delivery के बाद, pollen ovary vault तक ek लंबी pollen tube grow करता है, जो egg cell के sath fuse (fertilization) hokar seed बनती है।
Flowers contain the reproductive parts of angiosperms. A flower is bisexual if it contains both stamens and carpels (e.g. Hibiscus, mustard) [NCERT p.103], or unisexual if it contains either stamens or carpels (e.g. papaya, watermelon) [NCERT p.103].
Reproductive structures: Reproductive structures (reproduction structureएं):
- Stamen (पुंकेसर): The male reproductive part. It consists of the Anther (which produces yellow pollen grains) and Filament [NCERT p.103]. Stamen (पुंकेसर): Male reproductive part hai। Isme Anther (परागकोष - jo yellow pollen grains produce karta hai) aur Filament (तंतु) hote hain [NCERT p.103]।
- Carpel / Pistil (स्त्रीकेसर): The female reproductive part in the center of the flower. It consists of:Carpel / Pistil (स्त्रीकेसर): Flower ke center mein female reproductive part hai। Isme teen parts hote hain:
- Stigma (वर्तिकाग्र): The sticky top part that catches pollen [NCERT p.103]. Stigma (वर्तिकाग्र): Sticky top part jo pollen ko catch karta hai [NCERT p.103]।
- Style (वर्तिका): The long middle tube [NCERT p.103]. Style (वर्तिका): Beech ki lambi tube hoti hai [NCERT p.103]।
- Ovary (अंडाशय): The swollen bottom containing ovules (बीजांड). Each ovule contains an egg cell [NCERT p.103]. Ovary (अंडाशय): Swollen bottom part jisme ovules (बीजांड) hote hain। Har ovule ke andar ek egg cell (अंड cell) hoti hai [NCERT p.103]।
Double Fertilization Process: Double Fertilization Process (दोहरा निषेचन प्रक्रिया):
1. Pollination (परागण): Pollen grains must be transferred from the anther to the stigma [NCERT p.103]. If this occurs on the same flower, it is self-pollination. If transferred to a different flower via wind, water, or animal vectors, it is cross-pollination [NCERT p.104]. 1. Pollination (परागण): Pollen grains ko anther se stigma par transfer hona zaroori hai [NCERT p.103]। अगर ये same flower पर हो, तो self-pollination (स्व-परागण) kehte hain। Agar wind, water, ya animal vectors ke through doosre flower par transfer ho, toh use cross-pollination (पर-परागण) kehte hain [NCERT p.104]।
2. Pollen Tube Growth: After landing on the stigma, the pollen grain germinates. It grows a long pollen tube that travels down through the style to reach the ovary [NCERT p.104]. 2. Pollen Tube Growth: Stigma पर land करने के बाद, pollen grain germinate होता है। ये ek लंबी pollen tube (पराग नलिका) grow karta hai jo style ke through travel karke ovary tak anatomy follow karti hai [NCERT p.104]।
3. Zygote Fusion: The male germ-cell travels down the pollen tube and fuses with the female egg cell inside the ovule, forming a diploid zygote (युग्मनज) [NCERT p.104]. 3. Zygote Fusion: Male germ-cell pollen tube के through नीचे jata है और ovule के अंदर female egg cell के sath fuse हो jata है, jisse diploid zygote (युग्मनज) banta hai [NCERT p.104]।
4. Seed and Fruit Transition: The zygote divides repeatedly to form an embryo. The ovule develops a tough protective coat and gradually converts into a seed [NCERT p.104]. The ovary grows rapidly and ripens to become a fruit, while petals, sepals, and stamens fall off [NCERT p.104]. 4. Seed and Fruit Transition: Zygote repeatedly divide hokar embryo बनता है। Ovule ek tough protective coat develop करता है और dheere-dheere seed (बीज) mein convert ho jata hai [NCERT p.104]। Ovary tezi से grow करती है और pak कर fruit (फल) ban jati hai, jabki petals, sepals, aur stamens murjha kar gir jaate hain [NCERT p.104]।
Click "Pollinate" to drop a pollen grain on the sticky stigma, and watch the pollen tube grow down the style to fertilize the egg, turning the ovary into a tomato fruit. "Pollinate" पर click karke pollen grain को stigma पर drop करें, और dekhein kaise pollen tube style के through grow karke egg fertilize करती है और ovary को tomato fruit बनती है।
- Flowers contain stamens (male anther/pollen) and carpels (female stigma/style/ovary). Flowers में stamens (male anther/pollen) और carpels (female stigma/style/ovary) होते हैं।
- Pollination transfers pollen to the stigma, growing a tube down to fuse with the egg cell. Pollination, pollen grains को stigma पर transfer करता है, जहाँ से pollen tube grow होकर egg cell तक पहुँचती है।
- Post-fertilization, the ovule transitions into a seed, and the ovary ripens into a fruit. Fertilization के बाद, ovule, seed में convert हो जाता है और ovary पक कर fruit बन जाती है।
4. Sexual Reproduction in Human Beings 4. Sexual Reproduction in Human Beings (मानवों में लैंगिक reproduction)
Every month, the female uterus prepares a soft, cushiony bed of blood vessels and tissue—like preparing a nursery room in a house. If a fertilized egg arrives, it settles on this bed to grow. If no egg is fertilized, the nursery is not needed; it is dismantled and washed away (menstruation), resetting the monthly calendar. हर month female uterus blood vessels और tissues का ek soft, cushiony bed prepare करता है—जैसे ghar mein bache के लिए nursery room taiyar करना। अगर fertilized egg आता है, तो वह is bed पर grow hone के लिए settle हो jata है। अगर egg fertilize nahi होता, तो nursery ki ज़रूरत nahi रहती; ise dismantle karke wash कर दिया jata है (menstruation), और monthly calendar reset हो jata है।
Humans show clear differences at puberty (यौवनारंभ)—the period during adolescence when gametes start forming and reproductive organs mature [NCERT p.105].
A. Male Reproductive System A. Male Reproductive System (नर reproduction तंत्र)
The male system produces sperms and delivers them to the site of fertilization [NCERT p.107]: Male reproductive system sperms produce करता है और उन्हें fertilization ki site तक deliver करता है [NCERT p.107]।
- Testes (वृषण): Produce sperm cells and secrete the hormone testosterone [NCERT p.107]. They are located outside the abdominal cavity in the scrotum (वृषण कोष) because sperm formation requires a temperature lower than normal body temperature [NCERT p.107]. Testes (वृषण): Sperm cells produce karte hain aur testosterone hormone secrete करते हैं [NCERT p.107]। ये abdominal cavity के बाहर scrotum (वृषण कोष) mein located hote hain kyunki sperm formation ke liye normal body temperature se kam temperature ki zaroorat hoti hai [NCERT p.107]।
- Vas deferens (शुक्रवाहिका): Tubes that carry sperm from the testes to the urethra [NCERT p.107]. Vas deferens (शुक्रवाहिका): Ye tubes sperms ko testes se urethra tak carry karti hain [NCERT p.107]।
- Prostate Gland & Seminal Vesicles: Add secretions to sperm, making fluid transport easier and providing nutrients [NCERT p.107].
- Urethra: Forms a common passage for both sperms and urine [NCERT p.107]. Urethra (मूत्रमार्ग): Sperms aur urine dono ke liye ek common passage banata hai [NCERT p.107]।
B. Female Reproductive System B. Female Reproductive System (मादा reproduction तंत्र)
The female system produces egg cells and hosts the developing embryo [NCERT p.108]: Female reproductive system egg cells produce करता है और developing embryo को host करता है [NCERT p.108]।
- Ovaries (अंडाशय): Produce female gametes (eggs/ova) and secrete estrogen/progesterone. One egg is released every month by one of the ovaries [NCERT p.108]. Ovaries (अंडाशय): Female gametes (eggs/ova) produce karti hain aur estrogen/progesterone secrete karti hain। Ovaries dwara har mahine ek egg release kiya jata hai [NCERT p.108]।
- Oviducts / Fallopian Tubes (अंडवाहिका): Egg travels through these tubes. Fertilization (fusion of sperm and egg) occurs here [NCERT p.108]. Oviducts / Fallopian Tubes (अंडवाहिका): Egg in tubes ke through travel karta hai। Fertilization (sperm और egg का fusion) yahin होता है [NCERT p.108]।
- Uterus (गर्भाशय): A bag-like structure where the fertilized egg is implanted and grows into a fetus [NCERT p.108]. Uterus (गर्भाशय): Ek bag-like structure jahan fertilized egg implant hota hai aur fetus (भ्रूण) ke roop mein grow karta hai [NCERT p.108]।
C. What happens when the Egg is not Fertilised? C. What happens when the Egg is not Fertilised? (यदि अंड का निषेचन नहीं होता?)
If the egg cell is not fertilized, it lives for about one day [NCERT p.109]. Since the ovary releases one egg every month, the uterus prepares itself every month to receive a fertilized egg by thickening its inner lining with blood vessels for nourishment [NCERT p.109]. अगर egg cell fertilize nahi होता, तो ये lagbhag ek दिन तक zinda रहता है [NCERT p.109]। Ovaries हर month ek egg release करती हैं, isliye uterus fertilized egg receive करने के लिए हर mahine taiyari करता है और अपनी inner lining को blood vessels से thick और spongy बना leta है [NCERT p.109]।
When fertilization does not occur, this thick lining is no longer needed. It slowly breaks down and exits through the vagina as blood and mucus [NCERT p.109]. This monthly cycle of shedding is called menstruation (रजोधर्म) and lasts for about 2 to 8 days [NCERT p.109]. जब fertilization nahi होता, तो is thick lining ki ज़रूरत nahi रहती। ये lining dehre-dheere tootkar blood और mucus के roop mein vagina से बाहर निकलती है [NCERT p.109]। Is monthly cycle को menstruation (रजोधर्म / मासिक धर्म) kehte hain, jo lagbhag 2 se 8 din tak chalta hai [NCERT p.109]।
Rotate the slider dial to trace the 28-day cycle, watching changes in the uterine lining and hormone levels. 28-day cycle को trace करने के लिए slider dial को rotate करें, और uterine lining और hormone levels mein hone वाले badlaav को dekhein।
- Testes are in the scrotum outside the body to keep the temperature low for sperm development. Testes, body के बाहर scrotum में होते हैं ताकि sperms के development के लिए temperature कम रहे।
- Fertilization occurs in the fallopian tubes, and the embryo implants in the uterus walls. Fertilization, fallopian tubes में होता है, और zygote, uterus की walls में implant होता है।
- If fertilization does not occur, the uterus lining sheds monthly during menstruation. अगर fertilization नहीं होता, तो uterus की thick lining break हो जाती है जो menstruation के रूप में बाहर आती है।
5. Reproductive Health & Contraception
Preventing unwanted pregnancy is like setting up security gates:
• Condoms are physical walls blocking sperm entry.
• Oral pills are chemical messages changing hormone rules so no eggs are released.
• Copper-T is a local block in the uterus preventing implantation.
• Vasectomy/Tubectomy are permanent surgical cuts in the pipeline.
Sexual act can lead to pregnancy, which requires high physical and emotional preparedness in women [NCERT p.109]. To manage family size and timing, various contraceptive methods (गर्भनिरोधक तरीके) are used:
Contraceptive Categories: Contraceptive Categories (गर्भनिरोधक श्रेणियों):
- Mechanical Barriers (यांत्रिक अवरोध): Condoms or vaginal diaphragms. They prevent sperm from physically meeting the egg [NCERT p.109].
Advantage: Only condoms prevent transmission of Sexually Transmitted Infections (STIs) [NCERT p.109]. - Chemical Methods (Hormonal Pills): Oral pills change the body's hormonal balance so eggs are not released from ovaries [NCERT p.109]. Can cause minor side-effects due to hormone modifications. Chemical Methods (Hormonal Pills): Oral pills body के hormonal balance को change करती हैं taaki ovaries से eggs release na hon [NCERT p.109]। Hormone levels change करने के karan inke minor side-effects हो सकते हैं।
- Intrauterine Contraceptive Devices (IUCDs): Copper-T is placed inside the uterus by a doctor to prevent implantation of the zygote [NCERT p.109]. Can cause irritation. Intrauterine Contraceptive Devices (IUCDs): Copper-T को doctors द्वारा uterus mein place किया jata है taaki zygote का implantation na हो सके [NCERT p.109]। Isse local irritation हो सकती है।
- Surgical Methods (शल्य चिकित्सा):Surgical Methods (शल्य चिकित्सा):
- Vasectomy (पुरुष नसबंदी): The vas deferens in males is blocked, preventing sperm transfer [NCERT p.109]. Vasectomy (पुरुष नसबंदी): Males mein vas deferens ko block kar diya jata hai, jisse sperm transfer ruk jata hai [NCERT p.109]।
- Tubectomy (महिला नसबंदी): The fallopian tubes in females are blocked, preventing the egg from reaching the uterus [NCERT p.109]. Tubectomy (महिला नसबंदी): Females mein fallopian tubes ko block kiya jata hai, taaki egg uterus tak na pahunch sake [NCERT p.109]।
Sexually Transmitted Infections (STIs) Sexually Transmitted Infections (STIs) (यौन संचारित रोग):
Infections transmitted through sexual contact include: Sexual contact के through transmit होने वाली infections में include हैं:
- Bacterial STIs: Gonorrhoea and Syphilis [NCERT p.109]. Bacterial STIs: Gonorrhoea और Syphilis [NCERT p.109]।
- Viral STIs: Warts and HIV-AIDS [NCERT p.109]. Viral STIs: Warts और hiv-aids [NCERT p.109]।
Female Foeticide & Sex Ratio
For a healthy society, the male-female sex ratio must remain balanced. Due to reckless female foeticide (कन्या भ्रूण हत्या) via illegal prenatal sex determination tests, the female ratio has declined in several districts [NCERT p.110]. Prenatal sex determination is strictly banned by law to protect female child rights [NCERT p.110]. Ek healthy society ke liye, male-female sex ratio balanced hona zaroori hai। Illegal prenatal sex determination tests ke through hone wali female foeticide (कन्या भ्रूण हत्या) ki wajah se kai districts mein female ratio kam ho gaya hai [NCERT p.110]। Female child rights को protect करने के लिए law द्वारा prenatal sex determination strictly banned है [NCERT p.110]।
Drag the contraceptive items on the left and drop them into their correct biological action boxes on the right. Left side के contraceptive items को drag karke right side के correct biological action boxes mein drop करें।
- Condoms provide physical blocks to sperm, and are the only method that protects against viral and bacterial STIs. Condoms, sperms को block करते हैं और यह एकमात्र method है जो viral और bacterial STIs से बचाता है।
- Chemical pills stop egg release, Copper-T blocks implantation, and surgery blocks transport pipelines. Chemical pills egg release रोकती हैं, Copper-T implantation blocks करता है, और surgery transport pathways को block करती है।
- Law bans prenatal sex determination to maintain a balanced sex ratio and curb female foeticide. Law, sex ratio balance करने और female foeticide को रोकने के लिए prenatal sex determination को strictly ban करता है।
NCERT Solutions NCERT Solutions (पाठ्यपुस्तक के हल)
- It carries hereditary information from parents to offspring, ensuring the structural body design of the species is maintained. यह parents से offspring तक hereditary information carry करता है, जिससे species का body structure design maintain रहता है।
- It coordinates protein synthesis in new cells. यह new cells में protein synthesis को coordinate करता है।
- Minor errors during DNA copying generate variations, which are raw materials for evolution and adaptation. DNA copying में होने वाली छोटी errors, variations बनाती हैं, जो evolution और adaptation के लिए main source हैं।
| Feature Feature (लक्षण) | Binary Fission Binary Fission (द्विखंडन) | Multiple Fission Multiple Fission (बहुखंडन) |
|---|---|---|
| Number of offspring Offspring की sankhya | Parent cell splits into two equal daughter cells. Parent cell दो equal halves में divide होती है। | Parent cell divides into many daughter cells simultaneously. Parent cell एक साथ कई cells में divide होती है। |
| Protective cyst Protective cyst | Not formed. Nahi बनती. | A protective cyst wall is formed around the cell. Cell के charo taraf protective cyst बनती है. |
| Examples Examples | Amoeba, Leishmania. Amoeba, Leishmania. | Plasmodium (malaria parasite). Plasmodium (malaria parasite). |
- Spores are protected by thick walls that resist harsh conditions like heat, dryness, and lack of nutrients. They can survive dormant for long periods. Spores के पास thick protective walls होती हैं जो गर्म, शुष्क (dry) या unfavorable conditions को resist करती हैं, और वो लंबे समय तक dormant रह सकते हैं।
- Spores are light and easily dispersed by wind, allowing the organism to spread to new locations. Spores light weight होते हैं और हवा (wind) से आसानी से disperse हो जाते हैं, जिससे organism नए locations पर spread हो पाता है।
- A single sporangium produces thousands of spores, leading to rapid, large-scale multiplication. एक single sporangium हजारों spores produce करता है, जिससे rapid और large-scale multiplication होता है।
- Their bodies are organized into specialized tissues and organs, which are arranged in specific layouts. Simple cells cannot grow back complex organs on their own. उनकी body specialized tissues और organs से organized होती है। Simple cells बिना किसी sequencing के complex organs grow नहीं कर सकतीं।
- Complex organisms lack the high concentration of undifferentiated, multi-potent regenerative cells found in Planaria or Hydra. Complex organisms में Planaria या Hydra जैसे specialized, undifferentiated cells नहीं होतीं।
- Their development follows a set sequence of embryological differentiation. उनका development, cell division और embryological differentiation के set sequence को follow करता है।
- It allows propagation of seedless plants (banana, orange, jasmine, rose) that cannot grow from seeds. यह seedless plants (banana, orange, jasmine, rose) के propagation में help करता है जो seeds produce नहीं करते।
- Vegetative plants grow faster and bear flowers and fruits earlier than seed-grown plants. Vegetative plants, seed-grown plants के comparison में तेज़ी से grow करते हैं और fruits/flowers जल्दी देते हैं।
- Offspring are genetically identical clones of the parent, preserving desirable traits (like fruit sweetness). Offspring, parent plant के genetically identical (clones) होते हैं, जिससे desirable qualities (जैसे fruit की sweetness) preserved रहती हैं।
- Hydra Budding: Multicellular budding. The bud forms at a specific site due to repeated cell divisions, grows tentacles, matures, and detaches to live as a separate organism. Hydra Budding: Multicellular budding होती है। Bud specific site पर cellular divisions से बनता है, tentacles और mouth develop करता है, और mature होकर detach हो जाता है।
- Yeast Budding: Unicellular budding. The single cell forms a small protuberance (bud) that receives a split nucleus. The bud may remain attached, forming chains of budding yeast cells. Yeast Budding: Unicellular budding होती है। Single cell पर outgrowth बनती है जिसमें cell nucleus split होकर transfer होता है। Buds attached रह कर chain of cells भी बना सकती हैं।
- Development and enlargement of breast size, with darkening of skin of nipples. Breasts का size enlarge होना और nipples की skin dark होना।
- Growth of hair in armpits and pubic regions. Armpits और pubic region में hair growth होना।
- Broadening of hips and deposition of fat in thighs and buttocks. Hips का broad होना और thighs/buttocks पर fat deposit होना।
- Beginning of the menstrual cycle (menarche) and ovulation. Menstrual cycle (menarche) और ovulation शुरू होना।
- Oily skin, sometimes leading to acne. Skin oily होना, जिससे acne/pimples होते हैं।
- It is a disc embedded in the uterine wall. यह uterus की wall में embedded एक disc-like structure है।
- On the embryo's side, it contains villi to increase surface area. On the mother's side are blood spaces surrounding the villi [NCERT p.108]. Embryo की side पर इसमें absorption के लिए villi होते हैं, और mother की side पर blood spaces होते हैं जो villi को surround करते हैं [NCERT p.108]।
- This allows glucose, oxygen, and nutrients to pass from mother to embryo, and metabolic wastes to pass back to the mother's blood for excretion [NCERT p.108]. यह maternal tissue से glucose, oxygen और nutrients को embryo तक जाने देता है, और embryo के waste products को mother के blood में release कराता है [NCERT p.108]।
Solved PYQs Solved PYQs (विगत वर्षों के प्रश्न)
- It allows the propagation of seedless plants (like banana, grapes, orange, and rose) that have lost the capacity to produce seeds.
- All plants produced are genetically similar to the parent plant, preserving desirable traits (like fruit sweetness) [NCERT p.131].
- यह seedless plants (जैसे banana, grapes, orange, और rose) को उगाने में मदद करता है जो seeds produce करने की capacity खो चुके हैं।
- इससे तैयार होने वाले सभी plants parent plant के genetically similar (clones) होते हैं, जिससे desirable properties preserved रहती हैं [NCERT p.131]।
- The ovary releases one egg every month. In preparation, the uterus thickens its inner lining with blood vessels to receive a fertilized egg.
- If fertilization does not take place, this inner lining is no longer required. It slowly breaks down and escapes through the vagina as blood and mucus, lasting for 2 to 8 days [NCERT p.137].
- Ovary हर महीने एक egg release करती है। इसके लिए uterus अपनी inner lining को blood vessels से thick बना लेता है ताकि fertilized egg को receive कर सके।
- यदि fertilization नहीं होता, तो इस inner lining की कोई ज़रूरत नहीं रह जाती। यह lining धीरे-धीरे टूटकर blood और mucus के रूप में vagina के रास्ते बाहर निकल जाती है, जो 2 से 8 दिनों तक चलता है [NCERT p.137]।
- Mechanical Barriers (Condoms): Prevent sperm from reaching the egg. This is the only method that also protects against Sexually Transmitted Infections (STIs).
- Chemical Methods (Oral Pills): Change hormonal balance to prevent egg release (ovulation).
- Intrauterine Devices (IUDs like Copper-T): Placed in the uterus to prevent zygote implantation.
- Surgical Methods (Vasectomy/Tubectomy): Block the transport pathways (vas deferens in males or fallopian tubes in females) to permanently prevent fertilization [NCERT pp.139-140].
- Mechanical Barriers (Condoms): ये sperm को egg तक पहुँचने से रोकते हैं। यह एकमात्र ऐसा method है जो Sexually Transmitted Infections (STIs) से भी बचाता है।
- Chemical Methods (Oral Pills): ये body के hormonal balance को change करके egg release (ovulation) को रोकते हैं।
- Intrauterine Devices (Copper-T): इन्हें uterus में zygote के implantation को रोकने के लिए लगाया जाता है।
- Surgical Methods (Vasectomy/Tubectomy): ये male के vas deferens या female के fallopian tube को block करके fertilization को permanently रोकते हैं [NCERT pp.139-140]।
- NCERT Class 10 Science, Chapter 7: How do Organisms Reproduce?, pp. 127–141 (New pagination). NCERT Class 10 Science, Chapter 7: How do Organisms Reproduce?, pp. 127–141 (New pagination).
- CBSE Board Secondary Curriculum Class 10 Science Guidelines. CBSE Board Secondary Curriculum Class 10 Science Guidelines.