Q: Fact 1: When electricity flows to a light bulb , the light bulb will turn on. Fact 2: Materials that control the flow of electricity are called resistors. Given the two facts above, what could prevent a light bult from turning on? | OPTIONS:
- sensory neurons
- herbicide
- A resistor
- focusing a lens
- evaporation
- heat energy
- heating liquids
- energy barrier
A: A resistor

Q: Fact 1: Mutations are essential for evolution to occur. Fact 2: Natural selection is the mechanism of evolution. Given the two facts above, what enables natural selection to occur? | OPTIONS:
- environment
- mutations
- competition
- relocation
- Darwin
- evolutionary development
- root growth
- research
A: mutations

Q: Fact 1: Ultraviolet light causes sunburn. Fact 2: Sunburns are painful and can be dangerous. Given the two facts above, what can be painful and dangerous? | OPTIONS:
- Brutal temperatures
- smoking cigarettes
- Pesticides
- ultraviolet light
- weathering
- hyperthyroidism
- nutrients
- oxygen
A: ultraviolet light

Q: Fact 1: Molecules of tRNA bring amino acids to the ribosome in the correct sequence. Fact 2: Gene sequences can only give the amino acid sequence that is translated by the ribosome. Given the two facts above, what can bring amino acids in the correct sequence? | OPTIONS:
- body morphing
- Organic compounds
- flow of electrons
- acid sequences
- gene sequences
- A computer
- gene markups
- A Greek letter
A: gene sequences