AP Biology

What are elements in chemistry?

Elements in chemistry are pure substances that cannot be broken down into simpler substances by chemical means. They consist of only one type of atom and are represented on the periodic table.

Which four elements are primarily involved in building biological molecules?

Oxygen (O), carbon (C), hydrogen (H), and nitrogen (N).

What is a trace element?

An element required by an organism only in very small quantities, such as iron (Fe), iodine (I), and copper (Cu).

What are the three subatomic particles that make up an atom?

Protons, neutrons, and electrons.

What is an ionic bond?

A bond formed between two atoms when one or more electrons are transferred from one atom to the other.

What is a covalent bond?

A bond formed when electrons are shared between atoms.

What unique properties does water exhibit due to hydrogen bonding?

Cohesion, adhesion, surface tension, high heat capacity, and expansion on freezing.

What is the range of the pH scale?

1 to 14, with 7 considered neutral.

What are the four classes of organic compounds central to life?

Carbohydrates, proteins, lipids, and nucleic acids.

What is the primary function of carbohydrates in living organisms?

To serve as an energy source.

How are disaccharides formed?

By the joining of two monosaccharides through a glycosidic linkage.

What is the structure of proteins based on?

Amino acids, which are the building blocks of proteins.

What are the primary functions of lipids?

They serve as structural components of cell membranes, sources of insulation, signaling molecules, and energy storage.

What are the two primary types of cells?

Prokaryotic cells and eukaryotic cells.

What is the function of ribosomes?

To serve as the site of protein synthesis.

What happens during glycolysis?

Glucose is split into two molecules of pyruvic acid, producing 2 ATP and 2 NADH.

Define natural selection.

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

What is a mutation?

An error in the genetic code that can lead to changes in an organism's traits.

What is photosynthesis?

The process by which light energy is converted to chemical energy in plants.

What do the terms homozygous and heterozygous refer to?

Homozygous refers to having two identical alleles for a trait, while heterozygous refers to having two different alleles.

What is a Punnett square used for?

To predict the results of genetic crosses.

What are trophic levels?

The hierarchical levels in an ecosystem, comprising producers, primary consumers, secondary consumers, and tertiary consumers.

What is the role of decomposers in an ecosystem?

To break down dead organic material, recycling nutrients back into the ecosystem.