Q: What are the three classifications of elements? Choices: - metals, non-metals and alkaloids - metals, metaloids, and alkaloids - alkaloids, metaloids, and non-metals - metals, non-metals and metaloids A:
metals, non-metals and metaloids

Q: Because atoms have equal numbers of positive protons and negative electrons, what kind of electric charge do they possess? Choices: - none - positive - negative - neutral A:
neutral

Q: Q: What is the most widely accepted theory explaining how muscle fibers contract? Choices: - sliding pigment theoery - sliding tritium theory - sliding carbon theory - sliding filament theory A:
A: sliding filament theory

Question: Q: Catecholamines are a class of amine hormones synthesised form which amino acid? Choices: - epinephrine - dopamine - phenylalanine - tyrosine A:
Answer: tyrosine

*Question*
Q: Name the law that determines as to which rock layers are younger or older than others. Choices: - law of gravity - geologic theory - law of apposition - law of superposition A:
**Answer**
law of superposition

*Question*
Q: Most ecosystems are disturbed too often to attain what final, stable status? Choices: - undisrupted community - calm community - even community - climax community A:
**Answer**
climax community