Observation
process of noticing and describing events or processes in a careful, orderly way
Hypothesis
possible explanation for a set of observations that can be tested in ways that will support or reject
Control Group
the group that is exposed to the same conditions as the experimental group, except the independent variable
Experimental Group
the group for which the independent variable is changed
Quantitative Data
data that is obtained by counting or measuring
Qualitative Data
data that cannot be counted or measured; descriptive
Theory
well-tested explanation that unifies a broad range of observations and hypotheses, and allows scientists to make accurate predictions about new situations
Law
considered universal & invariable facts of the physical world
Stimulus
Anything external or internal that causes the organism to react but has to be living
Response
the reaction to a stimulus
Homeostasis
regulation of an organism's internal environment to maintain conditions suitable for survival
Compound Light Microscope
a microscope that uses a series of lenses to magnify objects
Scanning Electron Microscope (SEM)
a microscope that allows you to study the surface of a specimen (x10,000)
Transmission Electron Microscope
a microscope used to study slices of organisms (x100,000)
Matter
anything that occupies space and has mass
Mass
the amount of matter in an object
Volume
amount of space an matter takes up
Density
ratio of matter's mass to its volume
Physical State
form in which matter exists
Physical Change
a change in a substance that does not involve a change in the identity of the substance
Chemical Change
a change in a substance that changes the substance into a new substance; cannot be replaced
Proton
relatively large mass, positive charge
Neutron
relatively large mass, no charge
Electrons
relatively small mass, negative charge
Cation
atoms that lose electrons becoming positively charged
Anion
atoms that gain electrons becoming negatively charged
Covalent Bonds
bonds created by sharing electrons with other atoms
Ionic Bonds
bonds created by stealing electrons
Hydrogen Bond
when attractions between a hydrogen atom and another atom (negatively charged)
Cohesion
an attraction between molecules of the same substance
Adhesion
an attraction between molecules of different substances
Solute
substance getting dissolved
Solvent
liquid that does the dissolving
Carbohydrates
compounds of carbon, hydrogen, and oxygen atoms, usually in a 1:2:1 ratio
Lipids
macromolecule made mainly from carbon and hydrogen atoms (only macromolecule that isn't a polymer)
Nucleic Acids
macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus
Proteins
macromolecules that contain nitrogen as well as carbon, hydrogen, oxygen, and sometimes sulfur
Dehydration Synthesis
a way to form bonds between monomers by taking out water
Hydrolysis
a way to break bonds by inserting water
Monosaccharide
simplest carbohydrate, A.K.A simple sugars (glucose and fructose)
Disaccharide
sugars made of 2 covalently bonded monosaccharides (sucrose)
Polysaccharide
giant polymers that consist of thousands of linked monosaccharides
Saturated Fats
only single bonded between carbons
Unsaturated Fats
one double bond between carbons
Polysaturated Fats
more than one double bond between carbons
Exergonic Reactions
chemical reactions that release energy
Endergonic Reactions
energy absorbing reactions
Enzymes
protein catalysts that are used to speed up the rate of specific biological reactions
Prokaryote
cell with no membrane-bound organelles
Eukaryote
cell that contains membrane bound organelles
Passive Transport
Movement across the cell membrane that does not require energy from the cell
Active Transport
movement across the membrane against the concentration gradient and requires energy from the cell
Concentration Gradient
an unequal distribution of molecules
Facilitated Diffusion
the process of diffusion in which molecules pass across the membrane through the cell membrane channels
Osmosis
facilitated diffusion of water through a selectively permeable membrane
Hypertonic
water flows out of the cell
Hypotonic
water flows into the cell
Isotonic
water flows in and out of the cell at the same time
Turgor Pressure
positive pressure in a cell resulting from osmotic pressure
Plasmolysis
when the plasma membrane rips away from the cell
Endocytosis
process by which a cell surrounds and takes in materials
Exocytosis
expulsion or secretion of material from a cell
ATP (Adenosine Triphosphate)
compound used by cells to store and release energy
Heterotrophs
organisms that obtain food by consuming other living things
Autosomes
organisms that make their own food
Thylakoids
saclike photosynthetic membranes
Grana
stacks of thylakoids
Stroma
fluid portion of the chloroplast; outside of the thylakoids
Aerobic
process that requires oxygen
Anaerobic
process that does not require oxygen
Glycolysis
first set of reactions in cellular respiration in which a molecule of glucose is broken into two molecules of pyruvic acid
Asexual Reproduction
process by which a single parent reproduces by itself
Sexual Reproduction
a reproductive process that involves two parents that combine their genetic material to produce a new organism
Mitosis
a series of phases in cell division during which a nucleus of a cell divides into two identical daughter cells
Cytokenesis
cytoplasm of the cell divides the cell into two daughter cells
Cancer
malignant growth caused by uncontrolled cell division
Totipotent
cells that are able to become any type of cell in the body
Pluripotent
cells that can develop into most, but not all, of the body's cell types
Multipotent
cells with more limited potential, but that can differentiate into many different types of differentiated cells
Meiosis
a type of cell division that results in 4 gametes containing half the number of chromosomes as a parent's cell
Diploid Cell
a cell with two of each type of chromosome (2n)
Haploid Cell
a cell containing one type of each type of chromosome (n)
Gametes
sex cells
Sperm
male gametes
Egg
female gamete
Fertilization
fusion of gametes to create offspring
Crossing-over
process in which chromosomes break and exchange parts of themselves to the other chromosome
Nondisjunction
the failure of homologous chromosomes to separate properly during meiosis
Traits
characteristics that are inherited
Hybrid
An organism that received different genetic information for a trait from each parent
Pure-bred
organisms that produce only offspring with parental traits when allowed to self-fertilize
Principle of Segregation
alleles for each gene separate from each other during meiosis, so the gamete carries only one allele for each gene
Principle of Dominance
when two alleles for a pair are different, one allele can control the other, "hiding" it
Principle of Independent Assortment
gene pairs can sperate into gametes randomly and independently of each other
Homozygous
two of the same type of allele
Heterozygous
two different alleles
Genotype
an organism's genetic makeup, or allele combinations.
Phenotype
the trait that is observed
Punnett Square
a grid for organizing genetic information
Linked Genes
genes that are on the same chromosome