Answer:True
Explanation:
Nerve impulse must reach a certain threshold in a neuron before action potential can be generated to intiate conduction of action potential.
Therefore if mutiple impulses are generated and these are not upto thresholds , no matter how strong the stimulI are-NO ACTION POTENTIAL WILL BE GENERATED.
THIS IS ALL OR NONE PRINCIPLE
The all or none hypotheses can be best explain with flushing of the water closet after using it. If required volume of water is not pumped into the water closet storage above, no matter how long the handle is push, FLUSHING WILL NOT TAKE PLACE.Thus the threshold volume of water must be met.
Answer:
uniformitarianism, Fossil groups, 48 million years ago.
Explanation:
- Uniformitarianism is the doctrine of uniformity that assumes that same environmental laws and process operate till date that has also occurred on the past but not with the same uniformity. Unlike the atmospheric that is short-lived and sudden changes over the period of time.
- William Smith was a geologist who has noticed a certain type of fossil in a certain layer of sedimentary and igneous rock. A similar layer of strata could be found in the areas that were further apart.
- The Permian period was from 229 to 251 million years and was the last period of the paleozoic era and is recorded for the last major extinction in the history of life in earth and it lasted for 48 million years.
Answer:
the second one
Explanation: IN the text it literally states it explicitly.
The alula is a small structure that is found on birds. It is located at the joint between the hand wing and the arm wings of birds and it is the freely moving, first digit of a bird's wing. It is normally used by birds in slow flight. In humans, the structure that is comparable to the alula is the thumb.
