Answer: option D.
Phenotype
Explanation:
Theory of natural selection shows that different organism survive, adapt and reproduce in their environment due to their different phenotypic variation. The phenotypic variation exist among individual organisms and it is heritable which is transfer from one generation to another.
Phenotype are traits or physical characteristics or observable characteristics of organism e.g organisms appearance, behavior e.t.c.
A mammals need for oxygen effects their heart rate because there could be some cases where they're in lack of oxygen causing them to be literally ' out of breath ' . Like climbing a mountain. The higher you go the less oxygen.
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The correct answer is www.biojobs.net - www.higheredjobs.org - www.dnrjobs.gov. This is found by looking at the top level domain of the url (ex .com). Out of that list, net is least credible, org is 2nd most credible, and gov is most credible.
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Soil develops in horizontal layers.If we cut vertically into the earth ,the different layers become visible.A soil profile is a sample taken from the surface down through the soil . The horizontal layers of soil are called soil Horizons.
Adaptions give the organism a better chance to survive