Our skin has receptors and muscles also have receptors which tells brain about how much tension is being exerted on it etc.
Metamorphic rock can change into igneous or sedimentary rock. Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. I hope my answer has come to your help. God bless and have a nice day ahead!
In order for plants to assimilate nitrogen directly into their system, the nitrogen must be in the form of nitrates. Nitrogen in the air and ammonia from decayed matter in the soil is converted to ammonium by decomposers and nitrogen-fixing bacteria. The ammonium is further nitrified to nitrates by nitrifying bacteria. Finally, the nitrates can then absorbed by the plants.
Answer:
1977 is when people first knew about archaebacteria