Chapter 13: Thermoregulation & Osmoregulation— Exercise Solution Explanation
Section 1: Multiple Choice Questions
Q1. Konsa term baaki teen ko cover karta hai? → (d) Homeostasis
Homeostasis ek broad/overall term hai jis ke andar Thermoregulation, Osmoregulation, aur Excretion teeno aate hain — ye teeno homeostasis ke parts hain.
Q2. Marine fishes paani ka nuksan kaise pura karti hain? → (b) Drinking seawater
Marine fish apne environment se hypotonic hoti hain, isliye paani jism se bahar nikalta rehta hai. Is nuksan ko pura karne ke liye ye seawater peeti rehti hain.
Q3. Freshwater fish paani mainly kaise haasil karti hai? → (c) Osmosis
Freshwater fish apne environment se hypertonic hoti hain, isliye paani gills ke through osmosis se khud-ba-khud andar aata rehta hai — inhe peene ki zaroorat nahi.
Q4. Endotherms ke liye heat ka primary source kya hai? → (b) Internal metabolism
Endotherms (jaise mammals, birds) apni body heat khud metabolism se paida karte hain, bahar ke source (sunlight) se nahi.
Q5. Human thermoregulation ka control center kya hai? → (b) Hypothalamus
Hypothalamus brain ka wo hissa hai jo body ke “thermostat” ki tarah kaam karta hai aur temperature control karta hai.
Q6. Konsa waste product excretion ke liye sab se zyada paani mangta hai? → (a) Ammonia
Ammonia bohot toxic hoti hai, isliye isay safely nikalne ke liye sab se zyada paani (~500 mL/g) chahiye hota hai.
Q7. Konsa nitrogenous waste sab se kam toxic aur paani mein na ghulnay wala hai? → (c) Uric acid
Uric acid sab se kam toxic hai aur poorly water-soluble hai, isliye semi-solid precipitate ki tarah nikalta hai.
Q8. Ammonia ka urea mein conversion jism ke kis hisse mein hota hai? → (a) Liver
Liver mein ammonia ko urea mein convert kiya jata hai taake ye kam toxic ho jaye aur kam paani se excrete ho sake.
Section 2: Short Questions
Q1. Osmoregulators aur Osmoconformers ki definition do.
Osmoregulators apni internal water/solute concentration ko constant rakhte hain chahe environment change ho (zyada tar vertebrates). Osmoconformers apni concentration environment ke barabar hone dete hain (jaise sharks, hagfish).
Q2. Thermoregulation define karo aur iski zaroorat batao.
Thermoregulation jism ka apna internal temperature stable rakhna hai. Ye isliye zaroori hai kyunke enzymes ek optimal temperature par best kaam karte hain — kam temperature par reactions slow hoti hain, zyada temperature par enzymes denature ho jate hain, aur cell membranes bhi temperature se affect hoti hain.
Q3. 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).
Q4. Differentiate karo:
(i) Osmoregulators vs Osmoconformers: Osmoregulators actively apni internal concentration ko environment se different rakhte hain; Osmoconformers apni concentration environment jaisi hone dete hain.
(ii) Ectotherms vs Endotherms: Ectotherms apni heat bahar se lete hain aur temperature environment ke sath badalta hai (fish, amphibians, reptiles). Endotherms khud metabolism se heat banate hain aur constant temperature rakhte hain (birds, mammals).
(iii) Vasodilatation vs Vasoconstriction: Vasodilatation mein skin ki blood vessels phailti hain taake zyada heat nikle (hyperthermia mein). Vasoconstriction mein vessels sikadti hain taake heat kam nikle (hypothermia mein).
(iv) Homeotherms vs Poikilotherms: Homeotherms internal “thermostat” se apna temperature constant rakhte hain (mammals, birds). Poikilotherms apna temperature narrow range mein nahi rakh sakte, environment ke sath badalta hai (fish, amphibians, reptiles, invertebrates).
(v) Ammoniotelic vs Ureotelic: Ammoniotelic organisms bohot toxic ammonia excrete karte hain (~500 mL paani/g chahiye) — freshwater/marine animals. Ureotelic organisms kam toxic urea excrete karte hain (~50 mL paani/g) — terrestrial animals.
(vi) Ureotelic vs Uricotelic: Ureotelic organisms urea excrete karte hain (~50 mL paani/g). Uricotelic organisms uric acid excrete karte hain, jo kam soluble hai, precipitate banata hai, aur sirf ~1 mL paani/g chahiye — insects, birds, reptiles, desert animals.
Section 3: Long Questions
Long Q1. Homeostatic mechanism chalane wale teen elements describe karo.
- Receptors: Changes detect kar ke control centre ko batate hain (jaise skin ke temperature receptors).
- Control Centre: Information process kar ke effectors ko message bhejta hai (brain, spinal cord, glands).
- Effectors: Response de kar system ko normal karte hain (muscles, glands) — jaise shivering aur vasoconstriction jab temperature gir jaye.
Long Q2. Homeostatic mechanisms ko negative aur positive feedback systems se relate karo.
- Negative Feedback: System ki activity kam karta hai, sab se common hai. Misal: temperature barhne par sweating hoti hai jo usay wapas normal kar deti hai.
- Positive Feedback: System ki activity barhata hai. Misal: bacha paida hote waqt contractions oxytocin release karwate hain jo aur contractions karwati hai.
- Relation: Dono same receptor → control centre → effector pathway use karte hain; negative feedback stimulus ko opose karta hai (stability ke liye), positive feedback stimulus ko reinforce karta hai (process complete karne ke liye). Agar positive feedback control na ho to health problems (jaise excessive inflammation) ho sakti hain.
Long Q3. Freshwater, marine, aur terrestrial habitats mein osmoregulation ke different methods explain karo.
- Freshwater: Hypertonic hote hain, paani osmosis se andar aata hai, salts bahar nikalte hain → dilute urine banate hain, salts active transport se wapas lete hain, kam paani peete hain.
- Marine: Hypotonic hote hain, paani bahar nikalta hai, salts andar aate hain → seawater peete hain, concentrated urine banate hain, chloride cells/kidneys/rectal glands se salt nikalte hain.
- Terrestrial: Paani evaporation, skin, aur excretion se khoya dete hain → impermeable covering, efficient kidneys, ammonia ko urea/uric acid mein convert karna, aur nocturnal/metabolic water par guzara.
Long Q4. Habitat ke lehaz se nitrogenous wastes ki nature explain karo.
- Ammonia (Ammoniotelic): Liver mein amino acids se banti hai, bohot toxic, ~500 mL paani/g chahiye — freshwater/marine animals.
- Urea (Ureotelic): Liver mein ammonia se banta hai, kam toxic, ~50 mL paani/g chahiye — terrestrial animals.
- Uric Acid (Uricotelic): Zyada energy se ammonia se banta hai, sab se kam toxic, poorly soluble, ~1 mL paani/g chahiye — insects, birds, reptiles, desert animals.
Long Q5. Jaanwaron ko body heat ke source ke lehaz se classify karo.
- Ectotherms: Heat bahar se lete hain, temperature environment ke sath badalta hai, low metabolism, behavioural thermoregulation (basking, shade) — invertebrates, fish, amphibians, reptiles.
- Endotherms: Heat khud metabolism se banate hain, constant temperature rakhte hain — shivering, brown fat, insulation use karte hain — birds, mammals.
Long Q6. Jaanwaron ko thermoregulate karne ki ability ke lehaz se classify karo.
- Poikilotherms: Temperature environment ke sath badalta hai — invertebrates, fish, amphibians, reptiles. Faida: Zyada khana nahi chahiye, isliye nutrient-poor jagah mein survive kar lete hain.
- Homeotherms: Hypothalamus se apna temperature constant rakhte hain — mammals, birds. Misal: insaan hamesha ~37°C rakhte hain.
Long Q7. Insaano mein thermoregulation ki regulatory strategies describe karo.
- Overview: Insaan endothermic homeotherms hain, negative feedback se temperature control karte hain. Skin/hypothalamus ke thermoreceptors changes detect kar ke hypothalamus ko batate hain, jo effectors ko activate karta hai.
- Hyperthermia (garmi) ka response: Vasodilation se blood flow barhta hai (heat release), sweating se cooling hoti hai, thyroxine kam ho kar metabolic rate kam karta hai.
- Hypothermia (sardi) ka response: Vasoconstriction se heat conserve hoti hai, shivering se heat banti hai, goosebumps insulating air trap karte hain, metabolic rate barh jata hai.
Inquisitive Questions
Q1. Positive feedback mechanisms insaano mein severe health problems se kyun juday hote hain?
Positive feedback original stimulus ko kam karne ke bajaye barhata hai. Agar loop time par band na ho to control se bahar chala jata hai — jaise unregulated cytokines se zyada inflammation aur tissue damage ho sakta hai.
Q2. Jaanwaron ke kuch behavioural responses batao jo homeostasis maintain karne ke liye hain.
Misal: thandi mein dhoop mein baithna, garmi mein saya dhoondna, thandi mausam mein dormant ho jana, desert jaanwaron ka din mein zameen ke andar rehna aur raat ko nikalna, insaano ka nahana ya fan/heater on karna.
Q3. Hormone ki misal le kar negative feedback ka flow chart banao.
Misal: Insulin se blood glucose regulation
- Stimulus: Blood glucose barh jata hai (khana khane ke baad)
- Receptor: Pancreas ke beta cells is rise ko detect karte hain
- Control Centre: Pancreas signal process karta hai
- Effector: Beta cells Insulin hormone release karte hain
- Response: Cells glucose absorb karte hain; liver glucose ko glycogen mein convert karta hai
- Result: Blood glucose level normal (set point) par wapas aa jata hai
- Negative Feedback: Jab glucose normal ho jaye to beta cells insulin release band kar dete hain
Ye negative feedback loop is liye kehlata hai kyunke output (kam hua glucose) apne hi original stimulus (high glucose) ko khatam kar deta hai.