Chapter 13: Thermoregulation & Osmoregulation— Short Questions Explanation
Homeostasis aur Feedback Mechanisms
Q1. Homeostasis kya hai?
Homeostasis wo ability hai jis se living organisms apna internal environment stable rakhte hain chahe bahar ka environment kitna bhi change ho. Jaise: insan ka body temperature 37°C par rehta hai chahe mausam garam ho ya sard.
Q2. Homeostasis ke main processes kya hain?
Thermoregulation (temperature ka control), Osmoregulation (paani-solute ka balance), aur Excretion (waste ka nikalna) — ye teenon homeostasis ke main processes hain.
Q3. Homeostasis ke mechanism mein kaunse steps shamil hain?
Homeostasis 3 cheezon se milkar chalti hai:
- Receptors – changes ko detect karte hain
- Control centre – information process kar ke effectors ko message bhejta hai
- Effectors – response de kar system ko wapas normal karte hain
Q4. Receptors kya hain?
Receptors wo special structures hain (organs, tissues, cells) jo internal ya external environment mein changes detect kar ke control centre ko batate hain. Misal: skin ke receptors temperature ka change detect karte hain.
Q5. Control centre kya hai? Kaunse organs ye kaam karte hain?
Control centre receptors se information leta hai, use process karta hai, aur effectors ko sahi message bhejta hai. Brain, spinal cord, aur endocrine glands control centre ki tarah kaam karte hain.
Q6. Effectors kya hain?
Effectors wo parts hain jo control centre ka message receive kar ke response dete hain aur internal environment ko normal karte hain. Misal: jab temperature kam ho jaye to muscles shivering se aur blood vessels vasoconstriction se temperature barhate hain.
Q7. Feedback mechanism kya hai? Iski types batao.
Jab system ka apna output us system ki activity ko control kare, usay feedback mechanism kehte hain. Iski 2 types hain: Positive Feedback aur Negative Feedback.
Q8. Positive feedback mechanism kya hai?
Isme output original stimulus ko aur barha deta hai (amplify karta hai). Ye kam common hai. Misal: bacha paida hote waqt uterus contractions se oxytocin release hoti hai, jo aur zyada contractions karwati hai — jab tak bacha paida na ho jaye.
Q9. Negative feedback mechanism kya hai?
Isme output system ki activity ko kam kar deta hai. Ye sab se common regulation hai. Misal: jab body temperature barh jaye to sweating shuru hoti hai, jis se temperature wapas normal ho jata hai.
Q10. Unregulated positive feedback kya hai?
Kabhi positive feedback control se bahar ho jata hai aur health problems paida karta hai. Misal: severe infection mein cytokines immune response ko barhate rehte hain, jis se zyada inflammation aur tissue damage ho sakta hai.
Q11. Positive feedback insaano mein health problems se kyun juda hota hai?
Kyunke positive feedback original stimulus ko kam karne ke bajaye barhata hai, isliye agar loop time par band na ho to control se bahar chala jata hai — jaise unregulated cytokines se zyada inflammation ho jati hai.
Q12. Jaanwaron ke behavioural responses batao jo homeostasis maintain karne ke liye hain.
Misal ke tor par: thandi mein dhoop mein baithna ya garam patharon par baithna, garmi mein saya dhoondna ya zameen mein ghusna, desert jaanwaron ka din mein zameen ke andar rehna aur raat ko nikalna, insaano ka nahana ya fan/heater on karna.
Osmoregulation
Q13. Osmoregulation ki definition do. Ye kyun zaroori hai?
Osmoregulation body fluids mein paani aur solutes ka balance rakhna hai. Ye zaroori hai kyunke blood pressure, organs ka kaam, aur metabolism sahi rakhne ke liye zaroori hai.
Q14. Osmosis aur Diffusion mein farq batao.
Osmosis sirf paani ka membrane ke through move hona hai (dilute se concentrated taraf). Diffusion kisi bhi particle ka high se low concentration ki taraf move hona hai — membrane zaroori nahi.
Q15. Osmoconformers aur Osmoregulators mein farq batao.
Osmoconformers apne body fluids ki concentration environment ke barabar hone dete hain (jaise sharks, hagfish). Osmoregulators apni internal concentration ko constant rakhte hain chahe bahar environment change ho (zyada tar vertebrates).
Q16. Freshwater mein osmoregulation ke problems aur solutions kya hain?
Freshwater jaanwar apne environment se hypertonic hote hain, isliye paani gills se andar aata rehta hai aur salts bahar nikalte hain. Solution: Zyada dilute urine banate hain aur salts ko active transport se wapas le lete hain, kam paani peete hain.
Q17. Freshwater habitat ke liye adaptations kya hain?
Ye jaanwar paani ko andar aane se rokte hain, extra paani dilute urine se nikalte hain, gills se salt wapas active transport karte hain, aur bohot kam paani peete hain.
Q18. Marine water mein osmoregulation ke problems aur solutions kya hain?
Marine jaanwar environment se hypotonic hote hain, isliye paani bahar nikalta hai aur salts andar aate hain. Solution: Samundari paani peete hain, kam magar concentrated urine banate hain, aur chloride cells (gills), kidneys, rectal glands se extra salt nikalte hain.
Q19. Marine water habitat ke liye adaptations kya hain?
Ye jaanwar continuously samundari paani peete hain, thoda aur concentrated urine banate hain, aur chloride cells (gills mein ATP se), kidneys, aur rectal glands se extra salt nikalte hain.
Q20. Terrestrial habitat mein osmoregulation ke problems aur solutions kya hain?
Khushk zameen ke jaanwar paani evaporation, skin, aur waste se khoya dete hain. Solution: Impermeable outer covering, efficient kidneys, aur ammonia ko urea/uric acid mein convert karna (kam paani chahiye hota hai).
Q21. Terrestrial habitat ke liye adaptations kya hain?
Insects ka waxy exoskeleton, reptiles ke waterproof scales, mammals/birds ki dead keratinized skin aur oil glands — ye sab evaporation rokte hain. Kidneys paani ko efficiently retain karte hain, aur ammonia ko urea/uric acid mein convert karte hain. Kuch jaanwar raat ko nikalte hain, aur Kangaroo Rat jaisay jaanwar metabolic paani par guzara karte hain.
Q22. Anhydrobiosis kya hai?
Kuch invertebrates (jaise tardigrades/water bears) apna almost sara paani kho kar dormant state mein chale jate hain, aur saal baad paani milne par dobara active ho jate hain.
Nitrogenous Waste aur Habitat
Q23. Ammoniotelic organisms kya hain? Ammonia kaise banti hai?
Ammoniotelic organisms ammonia excrete karte hain (fishes, protozoans, sponges) jinhe paani ki bohot zyada availability hoti hai. Ammonia amino acids se -NH2 group nikal kar H+ ke sath milne se banti hai — bohot toxic hoti hai, isliye 500 mL paani per gram chahiye.
Q24. Ureotelic organisms kya hain? Urea kaise banta hai?
Ureotelic organisms urea excrete karte hain (mostly terrestrial animals) kyunke ye ammonia ko zyada paani ke sath excrete nahi kar sakte. Urea liver mein ammonia se banta hai — sirf 50 mL paani per gram chahiye.
Q25. Uricotelic organisms kya hain? Uric acid kaise banta hai?
Uricotelic organisms uric acid excrete karte hain (insects, desert animals, birds, reptiles) jinhe paani bachana hota hai. Ammonia ko energy istemal kar ke uric acid mein convert karte hain — ye poorly soluble hai aur sirf 1 mL paani per gram chahiye.
Q26. Uric acid urea se toxicity mein kaise different hai?
Uric acid urea se kam toxic hai. Urea ko dilute karne ke liye 50 mL paani per gram chahiye, jabke uric acid ko sirf 1 mL chahiye kyunke ye semi-solid precipitate ki tarah nikalta hai, poora ghulnay ki zaroorat nahi.
Q27. Ammoniotelic aur Ureotelic organisms mein farq batao.
Ammoniotelic organisms ammonia excrete karte hain — bohot toxic, 500 mL paani per gram chahiye (fishes, protozoans). Ureotelic organisms urea excrete karte hain — kam toxic, sirf 50 mL paani chahiye (terrestrial animals), urea liver mein banta hai.
Q28. Ureotelic aur Uricotelic organisms mein farq batao.
Ureotelic organisms urea excrete karte hain — 50 mL paani per gram chahiye (mammals). Uricotelic organisms uric acid excrete karte hain — sirf 1 mL paani chahiye, semi-solid precipitate banta hai (insects, birds, reptiles, desert animals).
Thermoregulation
Q29. Thermoregulation ki definition do. Ye kyun zaroori hai?
Thermoregulation jism ka apna internal temperature stable rakhna hai chahe bahar ka environment kuch bhi ho. Zaroori isliye hai kyunke enzymes ek specific temperature par best kaam karte hain — kam temperature par reactions slow ho jate hain, zyada temperature par enzymes denature ho jate hain, aur cell membranes bhi temperature-sensitive hoti hain.
Q30. Ectotherms aur Endotherms mein farq batao.
Ectotherms apni heat bahar se lete hain, unka temperature environment ke sath badalta hai, metabolism slow hota hai (fishes, amphibians, reptiles). Endotherms apni heat andar se (metabolism se) banate hain aur constant temperature rakhte hain — shivering, brown fat, insulation use karte hain (birds, mammals).
Q31. Poikilotherms aur Homeotherms mein farq batao.
Poikilotherms apna temperature narrow range mein nahi rakh sakte, ye environment ke sath badalta hai (invertebrates, fishes, amphibians, reptiles). Homeotherms hypothalamus ko “thermostat” ki tarah use kar ke apna temperature constant rakhte hain (mammals, birds) — jaise insaan 37°C par rehte hain garmi-sardi dono mein.
Q32. Poikilotherm hona nutrient-poor environment mein kaise faida deta hai?
Poikilotherms ko apna temperature constant rakhne ke liye bohot zyada khana khane ki zaroorat nahi hoti, isliye wo kam khane wali (nutrient-poor) jagah mein bhi survive kar lete hain — jabke homeotherms ko continuously khana chahiye hota hai warna wo bhookay mar jayenge.
Q33. Thermoreceptors kya hain?
Thermoreceptors skin aur hypothalamus mein maujood special cells hain jo body temperature ka barhna/ghatna detect kar ke control centre (hypothalamus) ko signal bhejte hain. Ye humein garmi/sardi “feel” bhi karwate hain taake hum nahane ya fan/heater on karne jaisay voluntary actions le sakein.
Q34. Hyperthermia aur Hypothermia mein farq batao.
Hyperthermia mein body temperature set point (37°C) se barh jata hai — body vasodilation, sweating, aur thyroxine kam kar ke temperature normal karta hai. Hypothermia mein temperature set point se gir jata hai — body vasoconstriction, shivering, aur metabolic rate barha kar temperature normal karta hai.
Q35. Thermoregulate karne ki ability ke lehaz se jaanwaron ki 2 types kya hain?
Poikilotherms (jinka temperature environment ke sath badalta hai) aur Homeotherms (jo apna temperature constant rakhte hain).
Q36. Vasodilatation aur Vasoconstriction mein farq batao.
Vasodilation mein skin ki neechay blood capillaries phailti hain, jis se zyada blood surface par aata hai aur heat nikalti hai — ye hyperthermia mein hota hai. Vasoconstriction mein blood vessels sikadti hain, jis se skin ki taraf blood flow kam hota hai aur heat loss kam hoti hai — ye hypothermia mein hota hai.