Q: What is the method of evolution by which advantageous heritable traits become more common over generations? A:

OPTIONS:
- artificial selection
- same selection
- flow selection
- natural selection

Answer: natural selection

Problem: OPTIONS:
- compound mass
- mass effect
- atomic energy
- molecular mass
Q: Q: What is the sum of the masses of the atoms in a molecule? A:
Answer: molecular mass

Problem:OPTIONS:
- differential
- network
- worker
- operator

Q: When lactose is absent, a repressor protein binds to what? A:
****
A: operator

Q: How do amphibians reproduce? A:
OPTIONS:
- asexually
- biologically
- they don't
- sexually
sexually

Q: Amphibians may attract mates with what? A:
OPTIONS:
- only calls
- only scents
- neither
- calls or scents

Answer: calls or scents

input with options: Q: What type of pollutants enter the air directly? A:
OPTIONS:
- secondary
- liquid
- carbon
- primary
output:
primary