*Question*
Q: In the humoral response, what protein substances help neutralize or eliminate toxins and pathogens in the blood and lymph? Choices: - platelets - membranes - parasites - antibodies A:
**Answer**
antibodies

*Question*
Q: What heisenberg principle imposes ultimate limits on what is knowable in science? Choices: - impossibility principle - vacuum principle - certainty principle - uncertainty principle A:
**Answer**
uncertainty principle

*Question*
Q: Ice floats because it is less what than liquid water? Choices: - heavy - gaseous - warm - dense A:
**Answer**
dense

*Question*
Q: All matter in the universe is composed of one or more unique pure substances called what? Choices: - atoms - molecules - compounds - elements A:
**Answer**
elements