Biology BASIS 8 : PreComp

Qualitative Data

Characteristics that cannot be easily counted or measured.

Quantitative Data

Characteristics that are counted or measured.

Hypothesis

A predicted outcome of an experiment, proposed explanation.

Independent Variable

The variable that is intentionally changed in an experiment.

Dependent Variable

The variable that is observed or measured in an experiment.

Controlled Variable

Variables that are kept constant between groups in an experiment.

Control Group

The group used as a comparison for 'normal' in an experiment.

Mean

The average of a set of data points.

Median

The middle value when a data set is arranged in numerical order.

Mode

The most common value in a data set.

Cell Theory

The basic principles that all living things are made of one or more cells, the cell is the basic unit of life, and all cells come from preexisting cells.

Chloroplast

Organelle that performs photosynthesis by converting sunlight, carbon dioxide, and water into glucose.

Endoplasmic Reticulum

A network of membranes involved in protein and lipid synthesis; can be rough (with ribosomes) or smooth (without ribosomes).

Vesicle

Transport sacs that move materials throughout the cell, including during endocytosis and exocytosis.

Active Transport

The movement of materials against the concentration gradient, requiring energy.

Passive Transport

The movement of materials without the use of energy, going with the concentration gradient.

Isotonic Solution

A solution where the concentrations of solutes are equal across a membrane.

Hypotonic Solution

A solution with a lower concentration of solute compared to another solution.

Hypertonic Solution

A solution with a higher concentration of solute compared to another solution.

Photosynthesis

The process used by plants to convert light energy into chemical energy stored in carbohydrates.

Cellular Respiration

The process by which cells break down glucose and other food molecules in the presence of oxygen to release energy.

ATP

Adenosine triphosphate, the energy currency of the cell.

Enzyme

A biological catalyst that speeds up reactions by lowering the activation energy.

Hydrogen Bond

An attraction between hydrogen atoms and negatively charged poles of other molecules.

Covalent Bond

A bond formed when atoms share a pair of electrons.

Ionic Bond

A bond formed when one or more electrons are transferred from one atom to another.

Van der Waals Forces

Temporary and random attractions between non-polar molecules.

Contractile Vacuole

A structure in some unicellular organisms that pumps out excess water to prevent bursting.

Chromosome

Discrete units of DNA and associated proteins, linear in eukaryotes and circular in prokaryotes.

Producers

Organisms that produce their own food through photosynthesis, such as plants.

Consumers

Organisms that obtain energy by consuming other organisms.

Stomata

Small openings on the surface of leaves that allow gas exchange during photosynthesis.

Chlorophyll

A green pigment in plants that captures light energy for photosynthesis.

Light Reactions

The first stage of photosynthesis where sunlight is converted into chemical energy.

Calvin Cycle

The second stage of photosynthesis where carbon dioxide is fixed into glucose.

Fermentation

A process that allows cells to release energy from glucose without oxygen, producing lactic acid or ethanol.

NADH

A carrier molecule that stores energy used to produce ATP during cellular respiration.

Electron Transport Chain

A series of proteins in the inner mitochondrial membrane that transfers electrons to produce ATP.

Osmosis

The diffusion of water across a selectively permeable membrane.

Facilitated Diffusion

The process of passive transport of molecules across a membrane via protein channels.

Endocytosis

The process by which cells engulf large substances from their environment.

Exocytosis

The process by which a cell expels materials in vesicles.

ATP Synthase

An enzyme that creates ATP by using the energy from protons moving across a membrane.

Cell Membrane

A semi-permeable barrier that separates the interior of the cell from the external environment.