Answer:
The correct option is b. lower esophageal sphincter
Explanation:
The esophagus is the initial part of the digestive tract and its function is the transport of the alimentary bolus from the pharynx to the stomach, through the thorax and avoid the reflux thereof. It begins and ends in two sphincter structures, the upper esophageal sphincter and the lower esophageal sphincter, which separate it from the pharynx and stomach. The lower esophageal sphincter has two functions: relax during swallowing and prevent reflux of the gastric contents into the esophagus in the postdeglutory period. After swallowing, there is a relaxation of the lower esophageal sphincter, pressure dropping to levels similar to those of the gastric fundus, which allows the bolus to enter the stomach. This relaxation lasts a few seconds and is followed by a strong contraction that prevents backflow of food.
The answer is letter A. In most organisms cellular respiration usually involves oxygen to produce the most energy. Except in the process of fermentation, where the cells are deprived with oxygen causing it to form bacteria and other forms of organisms within the fermented sample.
Saturated fatty acids are different to unsaturated fatty acids because they have no C=C double bonds.
<h3>What are the differences between saturated and unsaturated fatty acids?</h3>
- Saturated fatty acids do not have C=C double bonds, while in unsaturated fatty acids there is at least one C=C double bond in the fatty acid chain.
- Saturated fats are usually solid at room temperature and are derived from animal sources, whereas unsaturated fats are usually liquid at room temperature and are from plant sources.
- One must reduce the amount of saturated fat in their diet and consume more unsaturated fats like olives, seeds and nuts.
- Unsaturated fats can be monounsaturated (contains only C=C double bond) or polyunsaturated (contains two or more C=C double bonds).
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The birth rate was greater than the death rate and the immigration rate was greater than the emigration rate. Options B and D are correct.
<h3>Population growth</h3>
From the illustrated image, the world experienced an upward growth in population between 1950 and 2010.
In order for population growth to occur:
- the birth rate must exceed the death rate
- immigration must exceed emigration
Either or both of the above conditions will lead to a growth in the population.
Thus, options B and D are correct.
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Red blood cells is the Andes
