The answer fam is..........D) One allele for each gene
It should be recorded in miligrams
Morphine and heroin have very similar structures, and they are classified into the group of opioids. All of the opioids, including morphine and heroin lock into endorphin receptors in the central nervous system causing a feeling of intense euphoria.
When a hypothesis has been tested several times using experiments and found to be true, such a hypothesis becomes a theory.
<h3>What is a theory?</h3>
A theory is a hypothesis that has been tested by experiments by several independent researchers.
Hypotheses are tentative statements without any scientific proof or backing. They can be tested using experiments.
Hypotheses remain accepted when there are supportive experimental data and become theories when several independent experiments support them.
More on scientific theories can be found here: brainly.com/question/2375277
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Answer:
Reproduction, heredity, variation in fitness or organisms.
Explanation:
Evolution occurs in organisms due to natural selection process because natural resources are limited. Evolution is the change in the characteristics of a species over several generations. If evolution occurs in the organisms so these evoluted organisms can survive rate more than those organisms where no evolution occurs because the evoluted organisms can adopt successfully the features of environment. Reproduction, heredity, variation in fitness or organisms are the four factors needed for natural selection to act.