Hello there!
The answer is enzymes.
Enzymes are biological catalysts, which means they decrease the amount of activation energy needed to start a reaction, therefore speeding up the rate of the reaction. They are part of the protein macromolecule group. Without them, our bodies would not process things efficiently or fast enough for us to live.
Hope I helped. Have a nice day.
Darwin's theory of Natural Selection
Because gametes (sex cells) are the only cells that pass along genetic information. Somatic cells are the cells that have already differentiated into various organs or tissues. They can't pass on a mutation to offspring because they're not involved in creating it.
The answer is D. They fuse during sexual reproduction
Overlapping niches lead to competition because they need the same resources such as food sources