Biology EOC Review

Cell Wall

A rigid structure that surrounds the cells of plants, fungi, many protists, and most bacteria

Chloroplast

A plastid containing chlorophyll; the site of photosynthesis

Chromatin

The DNA and proteins in a non-dividing cell

Chromosome

DNA and protein in a coiled, rod-shaped form that occurs during cell division

Cilium (cilia)

A short, hairlike organelle that extends from a cell and functions in locomotion

Cytoplasm

The region of a cell between the cell membrane and the nucleus

Cytoskeleton

A network of long protein strands in the cytosolthat helps maintain the size and shape of the eukaryotic cell

Cytosol (cytoplasm)

The gelatin like aqueous fluid that bathes the organelles on the inside of the cell membrane

Endoplasmic Reticulum

A system of membranous tubes and sacs in eukaroyotic cells that functions as a path along which molecules move from one part of the cell to the other

Flagellum (flagella)

A hair-like structure made up of microtubles that function in locomotion

Fluid Mosaic Model

A model of cell membranes structure representing the dynamic nature of membrane lipids and proteins

Golgi Apparatus

A system of membranes in eukaryotic cells that modifies protiens for export by the cell

Lysosome

A organelle containing digestive enzymes, existing primarily in animal cells

Microtubule

A hollow tube of protein that constitutes the largest strand in the cytoskelton

Mitochondria

The organelle that is the site of aerobic respiration in eukaryotic cells

Nuclear Envelope

A double membrane that surrounds the nucleus of eukaryotic cells

Nuclear Pore

A small hole in the nuclear envelope through which substances pass between the nucleus and the cytoplasm

Ribosome

An organelle that funtions in the synthesis of proteins

Rough Endoplasmic Reticulum

The portion of the endoplasmic reticulum that contains attached ribosomes

Selectively Permeable Membrane

A membrane that keeps some molecules out but allows others to pass through

Smooth Endoplasmic Reticulum

The portion of the endoplasmic reticulum that lacks attached ribosomes

Spindle Fiber

One of the microtubles that extend across a dividing eukaryotic cell; assists in the movement of chromosomes

Vacuole

A fluid filled organelle that store enzymes of metabolic waste material

Concentration Gradient

the difference of a concentration of substance across a space

Contractile Vacuole

an organelle in protists that expels water

Diffusion

the process, by which, molecules move from an area of greater concentration to an area of lesser concentration

Equilibrium

a state that exists when the concentration of a substance is equal throughout a space

Facilitated Diffusion

a process in which substances move down their concentration gradient across the cell membrane with the assistance of carrier proteins

Ion channel

a membrane protein that provides a passage way across the cell membrane through which the ion can diffuse

Osmosis

the diffusion of water through a selectively permeable membrane

Passive transport

the movement of substances across the cell membrane without the use of cell energy

Turgor Pressure

water pressure within a plant cell

Active Transport

the movement of a substance across the cell membrane against a concentration gradient; requires the cell to expend energy

Endocytosis

the process by which the cell surrounds and engulfs substances

Exocytosis

a process in which a vesicle inside the cell fuses with the cell membrane and releases its contents into the external environment

Phagocyte

a cell that in engages in phagocytosis

Phagocytosis

a type of endocytosis in which a cell engulfs large particles or whole cells

Sodium-Potassium Pump

a carrier protein that actively transports K+ ions into and Na+ ions out of cells

Vesicle

a membrane-bound sac in a eukaryotic cell that contains materials involved in endocytosis, exocytosis, or transport within a cell.

Cell

a membrane-bound structure that is the basic unit of life

Cell Membrane

the lipid bilayer that forms the outer boundary of a cell

Eukaryote

a cell that contains a nucleus and membrane-bound organelles

Nucleus

in an atom, the core of protons and neutrons; in a eukaryotic cell, the organelle that contains most of the DNA and directs most of the cell's activities

Organelle

one of several formed bodies with a specialized function that is suspended in the cytoplasm and found in eukaryotic cells

Prokaryote

a unicellular organism that lacks a nucleus and membrane-bound organelles

Organ

several types of body tissues that together perform a function

Organ System

a group of organs that interact to perform a set of related tasks

Tissue

in most multi-cellular organisms, a group of similar cells that carry out a common function

Birth rate

the ratio of live births in an area to the population of that area

Death rate

the ratio of deaths in an area to the population of that area

Life expectancy

an expected time to live as calculated on the basis of statistical probabilities

Population Density

number of individuals per unit area

Carrying capacity

largest number of individuals of a population that a environment can support

Emigration

movement of individuals out of a population

Exponential Growth

population growth pattern where a population grows faster as it increases in size

Growth rate

the rate of increase in size per unit time

Immigration

movement of individuals into an area occupied by an existing population

Inbreeding

the act of mating closely related individuals

Limiting factor

factor that causes the growth of a population to decrease

Logistic growth

growth pattern in which a population's growth rate slows or stops following a period of exponential growth

Archaebacteria

considered ancient life forms that evolved separately from bacteria and blue-green algae

Chemosynthesis

synthesis of carbohydrate from carbon dioxide and water

Endosymbiosis

a process in which unicellular organisms engulfed other cells, which became endosymbiants and eventually organelles in the host cell. gave rise to red and green algae., a process in which unicellular organisms engulfed other cells, which became endosymbiants and eventually organelles in the host cell. gave rise to red and green algae.

Ozone

a colorless gas (O3) soluble in alkalis and cold water

Species area effect

pattern of species richness; larger areas usually contain more species than smaller areas

Species diversity

the variety of organisms in a community

Stability

A community's resistance to change

Commensalism

the relation between two different kinds of organisms when one receives benefits from the other without damaging it

Competition

the struggle between organisms to survive in a habitat with limited resources

Herbivore

consumers that eat only producers

Host

an animal or plant that nourishes and supports a parasite

Mutualism

the relation between two different species of organisms that are interdependent

Parasite

an animal or plant that lives in or on a host (another animal or plant)

Parasitism

the relation between two different kinds of organisms in which one receives benefits from the other by causing damage to it (usually not fatal damage)

Pollinator

an insect that carries pollen from one flower to another

Predator

any animal that lives by preying on other animals

Prey

animal hunted or caught for food

Symbiosis

any relationship in which two species live closely together with mutalism, commensalism, parasitism

Carnivore

a consumer that consumes other consumers

Chemosynthesis

synthesis of carbohydrate from carbon dioxide and water

Consumer

an organism that obtains energy by eating other organisms

Decomposer

organisms in an ecosystem that break down organic material (dead organisms, their waste, etc.)

Detritivore

obtain energy from plant and animal remains and other dead matter

Food chain

(ecology) a community of organisms where each member is eaten in turn by another member

Food web

(ecology) a community of organisms where there are several interrelated food chains

Omnivore

an organisim that eats plants and animals

Producer

the bottom of the energy pyramid; includes any organism that makes its own food from raw materials

Trophic level

each step in a food chain or food web

Asexual reproduction

reproduction that does not involve the union of gametes and in which a single parent produces offspring that are genetically identical to the parent

Autotroph

An organism that obtains organic food molecules without eating other organisms or substanes derived from other organisms. These use energy from the sun or from the oxidation of inorganic substances to make organic molecules from inorganic ones.

Biology

the science that studies living organisms

Differentiation

(biology) the structural adaptation of some body part for a particular function, (biology) the structural adaptation of some body part for a particular function

DNA

(biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix

Ecology

the branch of biology concerned with the relations between organisms and their environment

Ecosystem

a system formed by the interaction of a community of organisms with their physical environment

Evolution

(biology) the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms

Evolve

change in a group of organisms over time

Gene

(genetics) a segment of DNA that is involved in producing a polypeptide chain

Heterotroph

an organism that depends on complex organic substances for nutrition

Homeostasis

metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes