Name the biofertiliser that fits each situation…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Name the biofertiliser that fits each situation.
- A pea crop whose roots carry round swellings.
- A flooded paddy field where an autotrophic microbe adds nitrogen.
- A bacterium that lives free in the soil and adds nitrogen to it.
- A fungus on roots that brings phosphorus from the soil.
- The enzyme of the nitrogen fixers that changes nitrogen gas into a usable form.
Need a reminder? The key ideaShow
Rhizobium lives in the root nodules of legumes and fixes nitrogen. Azospirillum and Azotobacter are free-living nitrogen fixers. Mycorrhiza, as in Glomus, bring phosphorus from the soil. Cyanobacteria are autotrophic nitrogen fixers of paddy fields. Urea is about nitrogen by mass, so the mass of urea is the mass of nitrogen divided by .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) Rhizobium, in the root nodules.
Step 2. (b) A cyanobacterium, for example Anabaena, Nostoc or Oscillatoria.
Step 3. (c) Azotobacter or Azospirillum.
Step 4. (d) A mycorrhiza, for example Glomus.
Step 5. (e) Nitrogenase.
Answer: (a) Rhizobium; (b) cyanobacteria; (c) Azotobacter or Azospirillum; (d) Glomus; (e) nitrogenase.
Discussion (0)
Log in to join the discussion.
Loading…