bio exam 1

What is science?

A method for understanding the natural world through observation and experiments.

What is biology?

The study of living things and their interactions.

What are the characteristics of life?

Growth, reproduction, response to stimuli, metabolism, homeostasis, adaptation, organization.

What is the hierarchy of life?

Atoms → Molecules → Cells → Tissues → Organs → Organ Systems → Organism → Population → Community → Ecosystem → Biosphere.

What is the scientific discovery process?

Observations → Questions → Hypothesis → Experiment → Data Analysis → Conclusion.

What is a hypothesis?

A testable statement.

What is a theory?

A well-supported explanation backed by evidence.

What is a variable in an experiment?

A factor that can change.

What is the independent variable?

What you change in an experiment.

What is the dependent variable?

What you measure in an experiment.

What is a controlled variable?

A variable that is kept constant during an experiment.

What are the 4 unifying themes of biology?

Evolution, Energy Flow, Information Flow (DNA), Structure & Function Relationship.

What are atoms composed of?

Protons (+), neutrons (0), and electrons (-).

What is the atomic number?

The number of protons in an atom.

What is the atomic mass?

The number of protons plus neutrons in an atom.

What are isotopes?

Atoms with the same number of protons but different numbers of neutrons.

What is the importance of isotopes?

Used in medicine for radiation therapy and medical imaging.

What is the octet rule?

Atoms are stable when they have 8 outer electrons.

What are ions?

Atoms that gain or lose electrons to become charged.

What defines the chemical identity of an atom?

The number of protons.

What is oxidation?

Losing electrons.

What is reduction?

Gaining electrons.

What are the types of chemical bonds?

Ionic, covalent, and hydrogen bonds.

What characterizes polar covalent bonds?

Unequal sharing of electrons.

What characterizes nonpolar covalent bonds?

Equal sharing of electrons.

What is electronegativity?

An atom's ability to attract electrons.

Why is water important for life?

It has cohesion, adhesion, and solvent abilities.

What happens during water ionization?

Water breaks into H+ and OH-.

What is the pH scale range for acids?

0-6 is acidic.

What do buffers do in biological systems?

Help maintain a stable pH.

What is carbon's ability in chemistry?

Carbon can form four bonds, creating complex molecules.

What are the 4 biological macromolecules?

Carbohydrates, lipids, proteins, nucleic acids.

What are monomers and polymers?

Monomers are single units; polymers are long chains of these units.

What distinguishes saturated fats from unsaturated fats?

Saturated fats are solid with single bonds; unsaturated fats are liquid with double bonds.

What is the function of the plasma membrane?

Controls what enters and exits the cell.

What is the cell theory?

All living things are made of cells; cells are the basic unit of life; cells come from existing cells.

What is the endosymbiotic theory?

Mitochondria and chloroplasts originated from bacteria.

What does selective permeability in membranes mean?

Only some substances can pass through membranes.

What is passive transport?

Transport that does not require energy.

What is active transport?

Transport that requires energy.

What is osmosis?

The movement of water to balance solute concentration.