Answer:
The correct answer is: upper esophageal sphincter.
Explanation:
The alimentary canal is a very long tract responsible for the digestion of the food. It is composed of several organs with many different and important functions. The alimentary canal also has a few sphincters, which are muscular valves that open and close when needed for the food to pass or be retained.
The first sphincter is the upper esophageal sphincter. One particularity of this sphincter is that is one of the few sphincters in the body that opens and closes under our conscious control, which happens when we decide to swallow our food.
From the first to the last, the order of the sphincters in the gastrointestinal tract is: upper esophageal sphincter, lower esophageal sphincter or gastroesophageal sphincter, pyloric sphincter, ileocecal sphincter, and anus.
The answer is Dilutions
Bacterial culture is one of the laboratory examination that could be used to determine if a specimen contain bacteria. But it will hard to count the colony if the bacteria count is too high.
That is why the specimen of the culture need to be diluted to reduce the bacteria count of the specimen, so the result will be easier to count. The unit used would be colony forming unit(CFU) per milliliter.
Answer:
The correct answer is option A.
Explanation:
Cellular organization is one of the characteristics of life that states that each living organism is made up cell or more than one cell, that is made up by organization of various components such as chemicals like micro molecule that form the macro molecule and these chemical level structural organization is formed together to make cells and this level of organization makes the tissue which is complex to cell but simpler to organ that is makeup of various together.
The makeup of organs is necessary as organs are the structural level that individuals facilitate the function and make up the organ system that is a complex system made up of organs that are similar in their function. The organism is the most complex of all levels.
Thus, the correct answer is option A.
The mitochondria. An organelle with a very curious history....
<span>Refractory period is the period after an initial stimulus when a neuron is not sensitive to another stimulus.</span><span>
During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that t</span>he voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane.
