Answer is A
Firstly axon must reach the threshold level and then depolarisation occurs. Depolarisation phrase means sodium enters and potassium leaves the axon . Choice C can't be because main idea is the entering of sodium ions.
<span>Ptyalin hydrolysis does not continue in the stomach because it is destroyed by the stomach once it enter the stomach. </span>
Ptyalin is an amylase enzyme commonly found in the saliva of
humans and animals. This enzyme is secreted in the mouth ( buccal cavity) and catalyze
the hydrolysis of starch into maltose and dextrin. Immediately the starch
leaves the mouth and enter the stomach, stomach acids destroy the ptyalin.
... During this process, plants cleave the carbon from the two oxygen molecules and release the oxygen back into the surrounding environment. Plants are thus primarily responsible for the presence of atmospheric oxygen.
PLS REPHRASE a bit SO YOU DONT GET BUSTED FOR PLAGIARISM
I believe that what is meant with the phrase "older explanation" is none other that superstition. Therefore, I will give you one superstitious belief which is now explained by science.
In Southeast Asia, people used to believe that St. Elmo's fire appears in remote areas because a bloody battle occured in that place leaving disembodied souls of the dead wandering there in the night and even in sunshine!
For generations, many people believed that this is a fact and some even say that these apparitions are diabolical or demonic in nature. So often, caution is advised to people whenever a ball of fire appears out in the open.
However, recent breakthroughs in the 21st century helped scientists to explain this mysterious phenomena. They found out that St. Elmo's fire is actually plasma, nothing special. Now, plasma is considered one of the states of matter! But mind you, it still does not explain why St. Elmo's fire seems to have a mind of its own!
We may lead to a presupposition that the researcher based its analysis on the environmental habitats of the organisms, moreover it can also be the almost identical but different morphological or physiological structures. There are many ways to classify an animal or base an animal, morphology, embryology, DNA and others.
