Free round worms have a more complex body system compared to parasitic roundworms because they are independent and exist as a whole organism. Parasitic round worms are less complex because they are dependent on their hosts for survival.
Polygenic traits-more than one gene controls the trait, like height or skin color
The answer to this question is "repairing old appliances"
Answer:
Natural selection is the process in nature by which organisms better adapted to their environment tend to survive and more than those less adapted to their environment. For example :treefrogs are sometimes eaten by snakes and birds
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