Unit 1 Biology Exam Review

What characteristics are used to determine whether something

is alive or not?

Made of cells, grows/develops, responds to stimuli, evolves, maintains homeostasis, uses energy, reproduces

Are viruses living or not? Defend your answer.

No, they cant reproduce on their own

Describe the term matter.

Anything that occupies space and has mass

What is the difference

between an element and a

compound?

An element consists of only one type of atom, while a compound consists of two or more different types of atoms bonded together.

What are the 6 most

common elements in living

things?

Carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur

What are the three components of an atom and what are

their charges?

Proton positive, electron negative, neutron neutral

What is the difference between an atom’s atomic number

and its mass number?

Atomic number is the number of proton and mass number is protons plus neutrons

Define the terms isotope and ion.

Element with the same number of protons but different number of neutrons. Ion is atom or molecule that lost 1 or more electrons, giving it a positive or negative charge

What is a ionic and covalent bond?

Ionic is metal + nonmetal and covalent is nonmetal + nonmetal

What is a polar and non polar bond?

Polar is unequal and nonpolar is equal

Summarize what happens during a chemical reaction.

The process of breaking the chemical bonds in reactant molecules and forming new chemical bonds to create product molecules.

What are the components of a chemical equation?

Reactant are 2H2 and O2, products are 2H2O

During a chemical reaction, is matter created or destroyed?

Matter cannot be created or destroyed

Why is a water molecule considered to be polar covalent?

Unequal electron sharing

Water molecules bond to one another using hydrogen

bonding. What does this look like at the molecular level?

Why does it happen this way?

Hydrogen bonding occurs because the water molecule is highly polar

What is adhesion?

Attraction between molecules of different substances

What is cohesion?

Attraction of molecules of the same substance

How are adhesion and cohesion used by organisms to

sustain life?

They are largely driven by the poor nature and hydrogen bonding of water and are critical for life processes in plants and animals

Explain how surface tension is related to cohesion.

The water molecules all have to stick together which is cohesion to form the force of the surface tension

What is capillary action? Describe its connection to

cohesion and adhesion.

It is the ability for liquid to flow up. For capillary action to occur, the adhesive forces must be stronger than the cohesive

How is water able to resist dramatic changes in temperature

compared to most other substances?

Specific heat capacity, which is a direct consequence of the hydrogen bonds between its molecules

Explain why/how ice has a lower density than liquid water.

Stable hydrogen bonds form during freezing and force the water molecules into an open structure that holds the molecules farther apart than they are in the more randomly packed liquid state

Define the terms solute, solvent, and aqueous solution.

Solute is what is being dissolved, solvent is what is doing the dissolving, and aqueous solution is any solution where water is the solvent

What is the difference between an acid and a base?

Acid is a substance that produces hydrogen atoms dissolved in water. Base is a substance that produces hydroxide atoms dissolved in water

How do acids and bases directly (or indirectly) affect the

hydrogen ion concentration of a solution?

Acid directly decreases concentration and bases indirectly decrease concentration

Explain the basis for the pH scale.

It’s the concentration of hydrogen atoms

What is a buffer and why is it important?

A chemical system that resists dramatic changes in pH when small amounts of acid or base are added. It is important for maintaining stable environments