The homeostasis of the human body works like a machine set at a particular standard. If the factors deviate from the standard values, the homeostatic mechanism come into action.
For example, if a cell requires certain protein, the respective genes get a signal and get activated. The cell start synthesizing the protein and when sufficient amount is made, there is a feedback loop, which allows the same protein to stop the synthesis as well. A lot of organs and cellular systems are involved in regulating the synthesis of this protein.
This is similar to the cooling system. If we set the temperature of the cooling system to certain degree, it will start cooling the room till the required temperature is reached. As soon as the temperature is acquired, the system cut-off automatically and the required temperature is maintained.
Answer:
He extracted and observed DNA from white blood cells.
Explanation:
Friedrich Miescher, who is a Swedish Botanist, is the scientist who isolated for the first time. In 1869, Miescher isolated a chemical he called NUCLEIN, which is called Nucleic acid now.
He discovered this so called "NUCLEIN" substance from the nuclei of white blood cells. Nucleic acids are the DNA and RNA we know today, hence, Miescher's discovery was significant to the genetic code as he even agitated for the inclusion of his discovery into inheritance.
1. Action potential reaches the axon terminal and depolarizes it.
2. Depolarization opens voltage-gated calcium channels, enabling influx of Ca into the neuron.
3. Calcium binds to specialized proteins on vesicles (containing pre-made acetylcholine) and triggers them to fuse with the neuron membrane at the synapse.
4. Exocytosis of acetylcholine into the synaptic cleft occurs.
5. Acetylcholine diffuses across the synapse and binds to nicotinic receptors on the end plate of the myocyte.
6. Activated nicotinic receptors, themselves ion channels, cause cation influx into the myocyte and generate an end plate potential. This eventually gives rise to the full depolarization within the myocyte that enables contraction.
Oviparity is a mode of reproduction in which young, developed in fertilized eggs, laid outside the mother's body. This mode of reproduction is found in most reptiles and all birds.
Viviparity means that their young develop inside the mother's body and are born alive. This is the mode of most mammals.
<span>Ovoviviparity is similar to viviparity in that there is internal fertilization and the young ones are born alive but differ in that there is no placental connection, the young are fed by egg yolk. This is found i</span><span>n </span><span>seahorses, for example.</span>