MCQ Science and Technology Class 9 Chapter 7 Maharashtra Board Energy Flow in an Ecosystem 1. Which process releases carbon dioxide back into the atmosphere after the death of organisms?PhotosynthesisRespirationDecompositionNitrogen fixationQuestion 1 of 202. What is the chemical equation for photosynthesis in the carbon cycle?C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy6CO₂ + 12H₂O → C₆H₁₂O₆ + 6H₂O + 6O₂6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂C₆H₁₂O₆ + 6H₂O → 6CO₂ + 6O₂Question 2 of 203. Which abiotic process releases carbon dioxide into the atmosphere?PhotosynthesisRespirationBurning of fossil fuelsNitrogen fixationQuestion 3 of 204. What maintains the equilibrium of oxygen and carbon dioxide in the atmosphere?DecomposersPlantsCarnivoresFossil fuelsQuestion 4 of 205. What percentage of the atmosphere is formed by oxygen?21%78%0.04%50%Question 5 of 206. Which process releases oxygen into the atmosphere?RespirationCombustionPhotosynthesisDecompositionQuestion 6 of 207. Which of the following uses oxygen in the oxygen cycle?PhotosynthesisRespirationNitrogen fixationAmmonificationQuestion 7 of 208. What makes the oxygen cycle complex?It involves only biotic componentsOxygen exists in various formsIt is a one-way processIt lacks abiotic componentsQuestion 8 of 209. Which form of oxygen is produced through atmospheric processes?O₂H₂OCO₂O₃Question 9 of 2010. What percentage of the atmosphere is nitrogen?21%50%78%0.04%Question 10 of 2011. What is nitrogen an important component of in organisms?Carbohydrates and fatsProteins and nucleic acidsSugars and starchesLipids and vitaminsQuestion 11 of 2012. Which process converts nitrogen into nitrates and nitrites?AmmonificationNitrificationDenitrificationNitrogen fixationQuestion 12 of 2013. What is the release of ammonia through decomposition called?Nitrogen fixationAmmonificationNitrificationDenitrificationQuestion 13 of 2014. Which process converts ammonia into a nitrite and then nitrate?Nitrogen fixationAmmonificationNitrificationDenitrificationQuestion 14 of 2015. What converts nitrogen compounds into gaseous nitrogen?DenitrificationNitrificationAmmonificationNitrogen fixationQuestion 15 of 2016. Which organisms are classified as primary consumers?CarnivoresHerbivoresOmnivoresDecomposersQuestion 16 of 2017. Which of the following is an apex consumer?FrogOwlLionBearQuestion 17 of 2018. What is the role of decomposers in the energy pyramid?They produce energyThey consume apex consumersThey dissipate energy as heatThey store energy in the sunQuestion 18 of 2019. Who studied the food chain and energy flow in 1942?EltonLindemanWhittakerDarwinQuestion 19 of 2020. What happens to the number of organisms from the lowest to the highest trophic level?It increasesIt remains constantIt decreasesIt fluctuatesQuestion 20 of 20 Loading...
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