<span>b.internal fertilization
</span>Sexual reproduction provides genetic variation because the sperm and egg that are produced contain different combinations of genes than the parent organism. Sexual reproduction involves meiosis which is the process of a cell doubling its DNA, shuffling its genes and then dividing the shuffled DNA among four cells.<span>Each resulting cell, or gamete from meiosis has only half the amount of DNA as the parent cell. So in order to form a new organism, two gametes, sperm and egg, must fuse, further mixing the genes to produce more genetic variation.</span>
Answer: Blood vessels
Explanation: Blood vessels consist of veins, venules, arteries, arterioles and capillaries that absorbs nutrients and minerals from organs and transport them to tissues and cells. It also transport oxygen and carbon dioxide to and from the heart to the lungs.
Therefore blood vessels are found in almost every organ, tissue and cells in the body to deliver nutrients, remove waste and filter lymph as part of immune system.
Answer:
Are slow building and offer advanced warning
Explanation:
Are slow building and offers advanced warning means it respond to changes within seconds. It's change is rapid though slow.
The answer is: "dopamine" .
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