Parietal cells produce gastric acid (hydrochloric acid) in response to histamine (via H2 receptors), acetylcholine (M3 receptors) and gastrin (gastrin receptors). Parietal cells contain an extensive secretory network (called canaliculi) from which the HCl is secreted by active transport into the stomach.
Answer:
The correct answer is - Observations generate a scientific question, leading to a hypothesis, which can be tested through an experiment.
Explanation:
In any scientific knowledge development process, scientists need to follow the scientific process in a particular sequence that helps in developing and testing a hypothesis.
The sequence has:
observation: Observation requires you to pay attention to occurrences around
Forming question: on the basis of observation form a question about why that occurrence happens.
Hypothesis formation: The hypothesis is your initial prediction on why that happens.
Experiment: The experiment is being done in order to collect data and analysis so you can test your hypothesis
Answer:
The correct answer would be phenotypic variation.
Phenotype refers to observable traits or characteristics of an individual. For example, height, color, shape, et cetera.
Phenotypic variation refers to the sum total of variations in characteristics within populations of the same species.
In contrast, genotypic variation refers to the sum total of variations (such as allele frequency) present in the genome of populations of the same species.