The process of conversion of atmospheric nitrogen into ammonia by microorganisms is:
A. Nitrification
B. Ammonification
C. Nitrogen fixation
D. Denitrification
Answer: Option C
Solution (By JKExamLibrary)
Biological nitrogen fixation, performed by bacteria (e.g., Rhizobium, Azotobacter) and cyanobacteria, reduces atmospheric N₂ to ammonia (NH₃) using the nitrogenase enzyme complex. Nitrification converts ammonia to nitrates, denitrification returns N₂ to atmosphere, ammonification releases ammonia from organic matter.
Explanation:
Incomplete dominance occurs when neither allele is completely dominant, resulting in a heterozygous phenotype that is a blend (e.g., red × white snapdragons produce pink). Codominance shows both alleles fully expressed (e.g., AB blood type). Complete dominance shows one allele masking another. Polygenic inheritance involves multiple genes contributing to a continuous trait.
Consider statements about environment: 1. The Chipko movement was for forest conservation. 2. Joint Forest Management involves local communities. 3. Biodiversity hotspots have low species richness. Which are correct?
Explanation:
The Chipko movement was a grassroots environmental movement in India where villagers hugged trees to prevent them from being cut down, highlighting forest conservation. Joint Forest Management (JFM) is a government initiative involving local communities in the protection and management of degraded forest lands. Biodiversity hotspots are regions with exceptionally high levels of species richness and endemism, not low. Thus, statements 1 and 2 are correct.
Explanation:
Photosynthesis converts CO₂ and H₂O into glucose and oxygen using light energy, catalyzed by chlorophyll in chloroplasts. This process sustains nearly all life, providing food and oxygen. Respiration releases energy from glucose, chemosynthesis uses chemical energy, transpiration is water loss.
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