A root emerges from a seed because of the force of OPTIONS:
- water against the seed coat.
- air pushing on the seed.
- gravity on the seed.
- soil pressing on the seed.
A: water against the seed coat.

A teacher demonstrates a chemical reaction. A student observes that the test tube in which the reaction occurs becomes warm. What is the source of the thermal energy generated by the reaction? OPTIONS:
- energy stored in the reactants
- breaking bonds of the reactants
- kinetic energy absorbed by the reaction
- potential energy absorbed by the reaction
A: energy stored in the reactants

DNA molecules contain the genetic information that determines the characteristics of a living organism. How do DNA molecules express the genetic information they contain? OPTIONS:
- by breaking down proteins within the cell
- by directing the process of protein synthesis
- by regulating the storage of cellular proteins
- by controlling the movement of protein molecules
A: by directing the process of protein synthesis

Which of these describes a property of all matter? OPTIONS:
- All matter gives off light.
- All matter is attracted by magnets.
- All matter is made of atoms.
- All matter dissolves in water.
A:
All matter is made of atoms.