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.
Answer:
Aluminum
Explanation:
The density of Aluminum is 2.7 g/cm3
We know the volume and mass of the unknown metal, as density is mass/volume: 81g/30cm3 = 2.7 g/cm3 which is the density of Aluminum :)
Explanation:
In complete dominance, the effect of one allele in a heterozygous genotype completely masks the effect of the other. The allele that masks the other is said to be dominant to the latter, and the allele that is masked is said to be recessive to the former.
<span>vascular cambium
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Apical Meristems are found in the tips of the roots and in the buds of the shoots. They supply cells for the plants to grow in length.
Apical Meristems are found in herbaceous plants, woody plants, grasses, and flowering plants.
In flowering plants, shoot apical meristem develops into an inflorescence meristem which produces the floral meristem. The floral meristem is responsible for the production of the sepals, petals, stamens, and carpels of the flower.
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How does a new hypothesis replace an older explanation of something in the natural world? To understand this let us look at one of the classical example of geocentric theory and heliocentric theory. The geocentric theory states the Earth is at the centre of the solar system and the Sun, Moon, and all the other planets revolve around it. This ancient theory failed to explain the phenomenon like the phases of Moon, solar eclipse and lunar eclipse. The modern heliocentric theory which states that the Sun is at the centre of solar system, and all the planets including the Earth revolve around it. This theory was able to explain all the phenomenons unlike the geocentric theory. Hence the heliocentric theory replaced the geocentric theory.
