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Modes of nutrition
Concepts tested here
- Autotrophs
All Questions
2012 AIPMT-MAINS 1 question
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How many organisms in the list given below are autotrophs?
$Lactobacillus$, $Nostoc$, $Chara$, $Nitrosomonas$, $Nitrobacter$, $Streptomyces$, $Saccharomyces$, $Trypanosoma$, $Porphyra$, $Wolffia$Autotrophs prepare their own food either by photosynthesis or by chemosynthesis.
Photoautotrophs in the list: $Nostoc$ (a cyanobacterium), $Chara$ (a green alga), $Porphyra$ (a red alga) and $Wolffia$ (a tiny angiosperm).
Chemoautotrophs in the list: $Nitrosomonas$ and $Nitrobacter$ (nitrifying bacteria that obtain energy by oxidising ammonia and nitrite).
Heterotrophs in the list: $Lactobacillus$ (a lactic acid bacterium), $Streptomyces$ (a saprophytic actinomycete), $Saccharomyces$ (yeast, a fungus) and $Trypanosoma$ (a parasitic protozoan).
Number of autotrophs = 4 + 2 = 6.
So six organisms are autotrophs.