*Question*
Q: Oxygen, carbon, hydrogen and what other element make up approximately 96% of living matter? Choices: - calcium - helium - silicon - nitrogen A:
**Answer**
nitrogen

*Question*
Q: What is the process by which organisms change in small ways over time? Choices: - spontaneous mutation - natural selection - adaptation - microevolution A:
**Answer**
microevolution

*Question*
Q: How many pathways do plants have for carbon fixation? Choices: - one - four - two - three A:
**Answer**
three

*Question*
Q: Which cell gives rise to all cells of the human body? Choices: - signaler stem cell - omnipoten stem cell - schwann stem cell - totipotent stem cell A:
**Answer**
totipotent stem cell