Answer: ensure blood flows toward your heart
Explanation:
These valves are what ensure blood flows toward your heart. Vein valves work hard, against gravity, to bring the blood that flowed down via arteries back up to your heart. When your vein valves are open and healthy, they are able to do their job properly, as the blood is easily able to flow up.
Answer:
The answer is A
Explanation:
Centrioles are only found in animal cells
The correct answer is D. a replication bubble. Hope this helps!
The answer is the Amoeba.
The Amoeba is the protozoan that can conduct
photosynthesis. They are often called amoeboid. Amoeba is a type of cell or
organism which can alter its shapes. They are found in every major lineage f eukaryotic
organisms. Amoeboid cells occurs in protozoa.
Creationists criticize the idea of natural selection as a circular argument, or tautology, claiming "the fittest are those that survive, and survival is how fitness is defined. "
The definition of natural selection is not tautological because natural selection is measured by contribution to the next generation, not simply survival of an individual organism.
Tautologies or circular arguments are true at all times and therefore are not productive as theories since they cannot be disproved. A tautology is a statement which is true by necessity.
Natural selection is the prevalent theory which explains biological change by predicting the mechanism behind evolution.
Nevertheless, natural selection can be explained non-tautologically. It should be described as the theory which tries to speculate as well as retrodict evolutionary change by environmental forces affecting the organisms.
To learn more about natural selection here
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