Answer:
Some adaptations are structural. Structural adaptations are physical features of an organism like the bill on a bird or the fur on a bear. Other adaptations are behavioral. Behavioral adaptations are the things organisms do to survive.
It primarily occurs in the leaves
Answer:
A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world.
Explanation:
The two-layered sac surrounding the heart is the pericardium.
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