Q: What types of living beings have water vascular systems and unique tube feet? Choices: - diatoms - mollusks - Ducks - echinoderms A:
echinoderms

Q: The external female reproductive structures are referred to collectively as what? Choices: - the cervix - the uterus - the Fallopian tube - the vulva A:
the vulva

Q: Q: Because action potentials are so brief, a neuron can produce hundreds per what? Choices: - day - minute - lifetime - second A:
A: second

Question: Q: What occurs in a formerly inhabited area that was disturbed? Choices: - spontaneous mutation - mass extinction - natural selection - secondary succession A:
Answer: secondary succession

*Question*
Q: Where does mechanical digestion begin? Choices: - intestines - brain - stomach - mouth A:
**Answer**
mouth

Q: Q: When we move down a group of elements on the periodic table, what happens to their electronegativity? Choices: - it increases - it stays the same - it doubles - it decreases A:
A: it decreases