E. are found in nitrogen-fixing cyanobacteria AND are used to protect nitrogenase.
Explanation:
Heterocysts are specialized cellular compartments found in nitrogen fixing cyanobacteria. They provide the ideal anaerobic environment for nitrogen fixation since nitrogenase enzyme cant work in presence of oxygen. Hence, in a cyanobacteria both the oxygen requiring photosynthesis process and the oxygen sensitive nitrogen fixation process takes place simultaneously.
Heterocysts have an additional cell wall made of glycolipid that provides a hydrophobic barrier to oxygen. They are involved in production of nitrogenase and other proteins that are required for nitrogen fixation. They also degrade photosystem II which is responsible for producing oxygen and produce proteins which remove any remaining oxygen.
The key processes in the fast carbon cycle include: Photosynthesis: the absorption of CO2 from the atmosphere (terrestrial plants) and from oceans (marine plants) to produce organic carbon structures. Respiration: the release of CO2 into the atmosphere, soil and oceans by animals as they exhale.
People with the sickle cell mutation in both copies of the HBB gene produce proteins that clump together and lead to changes in the shape and behavior of red blood cells.
Sperm cells when pollinated by the insect to the female body part stay there for a while til the part of the flower determines its suitability and once it is done the sperm travels down through the pollen tube.
