Glossary: Biology

New terms will be added as they become relevant to coursework or previous classes in order to keep these pages convenient for study.

A

 * Aerobic - requiring molecular oxygen to survive
 * Algae - plant-like autotrophic protists which photosynthesize, but lack roots, stems, and flowers of terrestrial plants
 * Alveoli - gas exchange structures within mammalian lungs, contain small blood vessels
 * Anaphase - the third stage of mitosis; the centromere splits apart and chromatids move to opposite ends of the cell
 * Angiosperm - a flowering plant; a plant that stores its seeds inside an ovary
 * Antibiotics - drugs that kill bacteria
 * Antibody - proteins which mark foreign pathogens for destruction
 * Antigen - a structure on a pathogen that causes an immune response
 * Anus - the orifice through which solid waste is expelled
 * Aorta - the primary artery in a human being which carries blood directly from the heart
 * Arteriole - a small artery which leads to capillaries
 * Arteriosclerosis - a condition where the interior surface of blood vessels are covered in deposits of fat
 * Artery - a blood vessel which carries blood away from the heart
 * Artificial selection - a process of culling offspring actively to promote the existence of predetermined traits
 * ATP - adenosine triphosphate, the main source of cellular energy
 * Autotroph - an organism which can produce its own energy

B

 * Binary fission - the asexual means of reproduction in unicellular organisms, resembles mitosis
 * Binomial nomenclature - the system of giving an organism a name with two words
 * Bioremediation - the process of using plants to extract heavy metals from soil; using plants to clean anything
 * Bronchi - the two branches leading from the larynx to the lungs in mammals
 * Bronchioles - the thinner branches stemming from the bronchi which deliver air to the entire lung

C

 * Capillary - the smallest blood vessels which facilitate gas exchange between tissue and allow for movement of waste and nutrients through its walls
 * Cell membrane - the selectively permeable protective layer encasing a cell; it controls nutrient and waste entering and exiting the cell
 * Centromere - the area of a chromosome where two sister chromatids are bound
 * Centrosome - an organelle which organizes the cell's microtubules and ensures the even distribution of cellular structures during mitosis
 * Chlorophyll - a green pigment found in plants that converts sunlight, CO2, and water to energy in photosynthesis
 * Chordata - the phylum containing vertebrate animals
 * Chromosome - structures within the nucleus which contain genetic information
 * Conjugation - a means of sexual reproduction for some bacteria
 * Cuticle - the waxy coating on the surface of plants that reduces water loss
 * Cytokinesis - the stage of cellular reproduction where the cytoplasm cleaves and results in two discrete daughter cells

D

 * Diffusion - the process of a molecules in a higher concentration spreading to areas of lower concentration
 * Diploid - cells that carry two copies of each chromosome
 * DNA - deoxyribonucleic acid; contains the genetic material used to construct an organism
 * Domain - the taxon above kingdom
 * Double helix - the shape of DNA

E

 * Endoplasmic reticulum - an organelle consisting of a series of flattened, membrane-bound sacs and tubes which is generally responsible for transporting substances within the cell
 * Enzyme - any protein in living organisms which initiates biochemical reactions without being consumed in the process
 * Epiglottis - a layer of tissue found in the esophagus which covers the opening to the trachea when swallowing
 * Eukaryote - an organism whose nucleus is bounded by a membrane

G

 * Gene - a section of DNA which codes for a particular trait (e.g. hair colour, eye colour, number of fingers)
 * Genotype - the complete genetic code of an organism
 * Golgi apparatus - a organelle; a stack of flattened, membrane-bound sacs connected to the endoplasmic reticulum and is responsible for mucus secretion and waste disposal
 * Gram-negative bacteria - bacteria lacking a significant peptidoglycan layer in their cell wall, blue in a Gram stain
 * Gram-positive bacteria - bacteria containing a significant peptidoglycan layer in their cell wall; pink in a Gram stain

H

 * Haploid - a cell containing half the organisms's total chromosomes (e.g. sperm, egg)
 * Hemoglobin - a pigment found in red blood cells which turns them red in the presence of oxygen; contains iron
 * Heterotroph - an organism which cannot produce its own food

I

 * Interphase - the period in a cell's life where it carries out its functions

K

 * Kingdom - the highest level of classification in the Linnaean era

L

 * Leukocyte - a type of white blood cell
 * Lysosome - an organelle; a membrane-bound vesicle responsible for breaking down other organelles

M

 * Meiosis - a form of sexual reproduction involving the combination of two gametes
 * Meristem - portions of a plant where undifferentiated cells differentiate
 * Metabolism - the total of all chemical reactions which keeps an organism alive
 * Metaphase - the second phase of mitosis; the stage where the chromosomes align along the equatorial plate
 * Microtubules - hollow protein rods which enable movement in a cell
 * Mitochondria - an organelle which facilitates energy production in a cell
 * Mitosis - the process of cellular division
 * Mutation - random changes in DNA; can be caused by disease, environmental factors, or for no reason
 * Mutualism - an interaction between two species that is mutually beneficial

N

 * Nucleus - the organelle that houses the genetic code of an organism

O

 * Organ - a group of two or more tissues working together to perform a function
 * Organelle - a structure within a cell that performs a specialized task
 * Osmosis - diffusion where water moves from higher concentration to lower concentration

P

 * Pathogen - an infectious agent
 * Peristalsis - a wave motion; used in the esophagus and the small intestine to push food along
 * Pharynx - a structure located behind the mouth, connecting the esophagus to the trachea
 * Phloem - vascular tissue that transports organic material in plants
 * Phototropism - the tendency for plants to grow towards light
 * Plasma - the fluid portion of the blood; high in nutrients
 * Prophase - the first phase of mitosis; the chromosomes become densely packed

R

 * Ribosome - tiny organelles responsible for the texture of the rough endoplasmic reticulum; synthesizes proteins from DNA

S

 * Seed - a reproductive structure of plants; an embryo surrounded by food and a hard coat
 * Selectively permeable membrane - a layer that allows some substances to pass through while being impervious to others
 * Sinoatrial node - a bundle of tissue which controls the heartbeat
 * Spores - reproductive cells of some fungi that are carried by the wind and other organisms

T

 * Taxon - a group
 * Taxonomy - the process of classifying and naming living organisms

V

 * Vascular bundle - the cylinder of xylem and phloem that connects the vascular tissue of the root to that in the leaves
 * Vascular tissue - tissue that transports materials in a plant
 * Vascular system - the system comprised of the vascular tissue
 * Ventricle - a chamber of the heart that collects blood to be pumped
 * Venule - a smaller vein that stems from the capillaries
 * Villi - small, finger-like projections that increase the surface area of the small intestines
 * Virus - strands of DNA which simulate genes and can parasitize cells

X

 * Xylem - vascular tissue that carries water in plants

Z

 * Zygote - a fertilized egg cell