At the end of the esophagus is a thick ring of a muscle called a sphincter which allows food to enter the stomach but not from the stomach back into the esophagus. Once the food enters the stomach it is mixed with the digestive juices.
Answer:
every thing is on the middle so i can apply
Answer:
The correct answer would be Gene pool for the population.
A gene pool is defined as the sum total of all the genes present in an inter-breeding population at a specific time.
It includes all the alleles of all the loci within the genes of a interbreeding population or species.
The composition of the gene pool of a population can change with course of a time due to evolution.
A large and diverse gene pool enhances the ability of a population to adapt, survive and evolve in a nature.
Sleep apnea option 3 is the correct answer .....I guess gotta check