"A gene pool consists of all genes, including all the different alleles that are present in a population. Number of times an allele occurs in a gene pool compared with the number of times other alleles occur. In genetic terms, evolution is any change in the relative frequency of alleles in a population."
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Answer:
A) parietal cells
Explanation:
Parietal cells are the epithelial cells of the stomach that have the function to secrete hydrochloric acid (HCl) and intrinsic factor. Parietal cells contain canaliculi – secretory network for the secretion of HCl via active transport.
Parietal cells are regulated via several factors such as acetylcholine, gastrin and histamine. So, if histamine receptors are blocked via antacid drugs , the secretion of the acid will be reduced.
Variations can be genetic or environmental, the traits are passed from one generation to other generation of snail is from from both parents to offspring and through the environment.
The correct answer is C.
Explanation:
Genetic variation in an organism is passed to the offspring by its parents.
environmental variation is the the result of different environment with which individual adapt.
Natural selection is a process in which a suitable trait which is well adapted to the environment is passed on tho future generations.
Genetic variation is the change in DNA or gene of the individual trait. The tree snails having different pattern in their shells is due to the habitat they are living in.
The snails which have well adapted to the environment are able to reproduce and pass on the traits to their progeny. The variation is due to the traits passed from parents through the environment also.
