*Question*
Q: What part of an atom is positive due to the presence of positively charged protons? Choices: - Neutron - Proton - Electron - nucleus A:
**Answer**
nucleus

*Question*
Q: How do birds learn to avoid eating monarch butterflies? Choices: - instinct - temperature - digestion - conditioning A:
**Answer**
conditioning

*Question*
Q: What thin layer of air acts as a barrier to prevent cool air from mixing with warm air in the stratosphere? Choices: - methosphere - endosphere - liposphere - tropopause A:
**Answer**
tropopause

*Question*
Q: What term is used to describe the process by which organisms give rise to offspring? Choices: - variation - photosynthesis - osmosis - reproduction A:
**Answer**
reproduction