ECOLOGY: The scientific study of interactions between organisms and their environment.
ECOSYSTEM: Interactions among populations in a community
EGG: A female, haploid gamete (sex cell) used for sexual reproduction. These cells are also known as ovum are are made during a process called meiosis.
ELECTRON: The negatively charged part(s) of an atom located on the outside of the atom.
ELEMENT: An element consists of atoms of only one type.
EMBRYO: Earliest stage of growth and development of both plants and animals; differences and similarities among embryos can provide evidence of evolution.
EMIGRATION: Movement of individuals from a population; this causes the population to decrease in size.
ENERGY PYRAMID: A pyramid that shows the amount of energy available at each trophic level. The bottom level with the most energy is the primary producers. Only 10% of the energy at one trophic level is transferred to the next level.
ENDOPLASMIC RETICULUM (ER): There are two types of ER- smooth and rough. Rough ER contains ribosomes. ER is like the road system of the cell. ER transports substances around the cell.
ENVIRONMENT: Biotic and abiotic surroundings to which an organism must constantly adjust; includes air, water, weather, temperature, other organisms, and many other factors.
ENZYME: A protein that speeds up chemical reactions by lowering the activation energy (speed bump) of a reaction.
Enzymes contain a special folded pocket called an active site where the substrate can bind. It works like a lock and key.
Enzymes contain a special folded pocket called an active site where the substrate can bind. It works like a lock and key.
EON: The largest unit of geologic time. An eon is composed of many eras. An example of an eon is the Phanerozoic eon.
EPIDEMIC: An outbreak of an infectious disease in a particular community or region.
EPOCH: The smallest unit of geologic time. Only the most recent era - the cenozoic - has been divided into epochs.
ERA: The second largest unit of geologic time. Eons are divided into eras. Eras are divided into periods. An example of an era is the Precambrian era.
ERROR: Mistake or poor decision; Two common errors in an experiment are not including a control group or changing too many variables at once
ESTUARY: Where freshwater and saltwater meet (brackish water). Estuaries filter pollutants, buffer against waves, and are the nurseries of the sea.
EUBACTERIA: Group of prokaryotes that have cells walls and a variety of structures. These are the only bacteria we come in contact with. Some species of eubacteria cause sickness in humans.
EUKARYOTE: A type of cell found in everything except bacteria. These cells are large and complex, and have membrane-bound organelles like a nucleus. Many eukaryotes are multicellular. "You are a EU-karyote!"
EUTROPHICATION: The process by which a dead zone can form:
1. Fertilizer or waste water enters a stream or lake as run-off, causing nitrate and phosphate levels to increase
2. Algae bloom, blocking out sunlight, killing aquatic plants
3. As the algae decompose, the number of bacteria increases
4. Dissolved oxygen levels drop and carbon dioxide levels increase, lowering the pH
5. Aquatic life must leave or die
1. Fertilizer or waste water enters a stream or lake as run-off, causing nitrate and phosphate levels to increase
2. Algae bloom, blocking out sunlight, killing aquatic plants
3. As the algae decompose, the number of bacteria increases
4. Dissolved oxygen levels drop and carbon dioxide levels increase, lowering the pH
5. Aquatic life must leave or die
EVOLUTION: Change in species over time.
EXPERIMENT: A procedure that tests a hypothesis by collecting information under controlled conditions.
EXPERIMENTAL GROUP: The group(s) where you the scientist change something; the group(s) that receive the independent variable.
EXPONENTIAL GROWTH: Growth pattern where a population grows faster as it increases in size; graph of an exponentially growing population resembles a J-shaped curve.