Answer:
"Action potential is a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern."
It is the mode through which a neuron transports electrical signals.
Explanation:
- Option - (a) is the best choice to choose from,
- <u>The refractory period :</u>
A second action potential cannot occur until the membrane has recovered or reestablished, this is the refractory period. The absolute refractory period coincides with inactivation of voltage-gated sodium channels which makes it impossible to generate another nerve impulse.
Answer:
Spirogyra is a genus of green algae that belong to the order Zygnematales. These free-flowing, filamentous algae are characterized by ribbon-shaped chloroplasts that are arranged in a helical manner inside the cells. So the name is derived from the spiral arrangement of chloroplasts in these algae.
Explanation:
An open fracture is most accurately defined as a fracture in which the overlying skin is no longer intact. A fracture is normally the break in the continuity of the bone. It is also called a compound fracture, in which the fracture is an open wound or break in the skin near the site of the broken bone. Immediate treatment for an open fracture focuses on preventing infection at the site of the injury.
Tissues are composed of the same kind of cell
<h2>Answer:</h2>
The two reasons are given below:
- Natural selection.
- Lack of food
<h3>Explanation:</h3>
Natural selection is the phenomenon of the evolution in which the organisms able to fit in the changing environment survive while other organism died. Hence the survival if the fittest and then these organisms. Further reproduce to give birth organisms more fit to the changing environment.
The long neck giraffe survive but short neck died. So the population of long neck increased while short neck go extinct.
Other reason is the change of food resource. The food resource change from grass to long trees.
