Q: Many of the protist species classified into the supergroup excavata are asymmetrical, single-celled organisms with a feeding groove "excavated" from one side. this supergroup includes heterotrophic predators, photosynthetic species, and these? Choices: - insects - reptiles - mammals - parasites A:
parasites

Q: When lactose is present in the cell, what allows the lac genes to be expressed? Choices: - concentration of repressor protein - binding of expressor protein - the addition of water - nonbinding of repressor protein A:
nonbinding of repressor protein

Q: Q: Birds have air sacs that store inhaled air and push it into their what? Choices: - beaks - bones - abdomens - lungs A:
A: lungs

Question: Q: Conversely, very large forces are created by liquids and solids when they try to expand but are constrained from doing sowhich is equivalent to compressing them to less than their normal volume. this often occurs when a contained material warms up, since most materials expand when they do this? Choices: - increase density - increase mass - decrease temperature - increase temperature A:
Answer: increase temperature

*Question*
Q: What events, resulting in death of over half of animal species, have occurred on earth at least five times in the past 540 million years? Choices: - mass migrations - microevolutions - spontaneous mutations - mass extinctions A:
**Answer**
mass extinctions

*Question*
Q: What external feature in human beings is responsible for balance? Choices: - tails - brain - hands - ears A:
**Answer**
ears