Cyanobacteria were the first photosynthetic autotrophs that used water molecules as the source of electrons. Cyanobacteria were the first autotrophs that performed oxygenic photosynthesis and carried out the splitting of water.
The process of splitting water released oxygen as a gas (O2) which was released in the atmosphere of the earth as a by-product. This led to the accumulation of oxygen in the atmosphere. Some cyanobacteria can fix nitrogen and have specialized cells called heterocyst which serve as the site for nitrogen fixation.
Damage to the corticospinal tract
indicates a sign of Babinski sign. the receptor detects a stimulus that is the
first event associated with reflex. What is the first event associated with a
reflex. muscle spindle (indicates
stretch on the muscle).
