Bio midterm

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