Characteristics of Life
This concept means the whole system has properties that its individual parts do not have.
Emergent properties
Cells that lack a nucleus and membrane-bound organelles.
Prokaryotic cells
The first step where a scientist is noticing something.
Observation
Anything that has mass and takes up space.
Matter
The attraction between water molecules.
Cohesion
The basic unit of life.
The cell
Cells that contain a nucleus and membrane-bound organelles.
Eukaryotic cells
A testable explanation for an observation.
Hypothesis
A substance made of two or more different elements.
Compound
The attraction between water and other substances.
Adhesion
This relationship explains that biological structures evolved to perform specific jobs.
Structure–function relationship
The domain that includes prokaryotic organisms commonly found in many environments.
Bacteria
This type of claim appears scientific but is based on stories rather than data.
Pseudoscience
The number of protons in an atom.
Atomic number
Water’s ability to absorb large amounts of heat before changing temperature.
High specific heat
All cells store genetic information in this molecule.
DNA
The domain known for organisms that often live in extreme environments.
Archaea
An association between two variables that does not prove cause.
Correlation
Electrons in this shell determine how atoms bond chemically.
Valence shell (outer electron shell)
The process where liquid water turns into gas and cools the surface.
Evaporation (evaporative cooling)
This theory explains both the unity and diversity of life.
Evolution
The domain that includes organisms with eukaryotic cells.
Eukarya
A scientist is studying how sunlight affects plant growth. She places identical plants in three groups: full sunlight, partial sunlight, and no sunlight. She measures the height of the plants after four weeks.
Identify the independent variable, dependent variable, and two controlled variables in this experiment.
Independent variable: Amount of sunlight
Dependent variable: Plant growth (height after four weeks)
Controlled variables: Type of plant, amount of water, soil type, pot size, time grown (any two)
Atoms that differ in number of neutrons but have the same atomic number.
Isotopes
What happens to water’s density when it freezes?
Density decreases (ice floats)