dominant trait is opposed to a recessive trait which is expressed only when two copies of the gene are present.
Answer: Natural selection is one of the forces of evolution and the enviroment where the species lives is the selection agent. For example, suppose a mosquitoes population in a environment free from insecticides, in this environment there's a high frequency of non-resistant mosquitoes because the environment is not exerting any pressure on the resistence trait. But when the environment changes and we use a insecticide upon the mosquitoes population, the populations changes because the non-resistant ones die but those resistant survive and beggin to reproduce more effectively. That's natural selection, differences in survival and reproduction between individuals with different phenotypes (traits) and this differences depend of environmental changes.
1- Pyloric sphincter
2-Duodenum
3- Bile duct
4-Pancreatic duct
5-Esophagus
6-Lower esophageal sphincter
7-Fundus of stomach
8- Cardia
9-Body of stomach
10-Pyloric part
The <span>esophagus(5) connects to the stomach.</span>
<span> The food passes,from the pharynx, to the esophagus, to the stomach. This process is aided by peristaltic movements done by esophagus muscles.
This organ contains two sphincters:</span><span>the upper and the lower esophageal sphincter.
</span>The stomach is divided into four parts:
<span><span>1-The cardia (8) - this part is connected to the esophagus and its where the epithelium changes from stratified squamous to columnar.
In this region is the lower esophageal sphincter (6).
</span>2--The fundus(7)- It's formed by the upper curvature of the stomach.
3- the body(9)- is the main part; and the biggest
4-The pylorus/</span><span> Pyloric part (10) - is the lower region. This part is connected to the small intestine, the duodenum. In this region there is a </span>
strong ring of muscle called the (<span>1) Pyloric sphincter.
In the first part of the duodenum there is a connection with a duct that comes from the pancreas -4-</span>Pancreatic duct .
There is another duct that ends in the duodenum called- <span>Bile duct, that caries bile to digest fats.</span>
Answer:
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Explanation: