The fossil record of Antarctica shows the presence of tropical plants, such as one particular species related to the present day breadfruit. Most plants cannot survive in prolonged temperatures of less than 6 degrees Celsius. Antarctica is freezing all year round and could only have supported tropical and sub tropical plants if it was once much closer to the equator.
The presence of fresh water species also suggest that the continent was closer to the equator. Antarctica is frozen solid with a thick ice sheet.....rivers would be frozen solid all year round or would be limited to water movement under glaciers that melt as a result of pressure and friction. This environment is not suitable to support large fresh water organisms.
The answer is; catalyst
These proteins are called enzymes. They work by lowering the activation energy of reactants and hence speed up the biochemical reaction. They are not affected in the process hence one enzyme molecule can catalyze many reactions. An example of such an enzyme is carbonic anhydrase that enables carbon dioxide to dissolve in blood plasma as carbonic acid.
Answer:
A
Explanation:
Logically, the cell would have two nuclei because karyokinesis (the division of the nucleus) occurs before cytokinesis (division of the cytoplasm).
Answer: ionotropic; metabotropic
Explanation:
A receptor can directly open the channel and exerts an ionotropic effect. The ionotropic effect takes place by the help of ionotropic receptors. These receptors are membrane bound receptor proteins which responds by the bonding of the ligand.
Due to ligand binding the channel opens and allows the movement of ions into the cells which helps in either increasing or decreasing the action potential.
The receptors can also bind to the ligand and produce metabotropic effect which means by the second messenger.
