Terms in this set (60)
Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.
A group of similar organisms that can breed and produce fertile offspring.
A group of individuals that belong to the same species and live in the same area.
An assemblage of different populations that live together in a defined area.
The scientific study of interactions among organisms and between organisms and their physical environment.
All the organisms that live in a place, together with their physical environment.
A group of ecosystems that share similar climates and typical organisms.
3.1 Biotic Factor
Any living part of the environment with which an organism might interact, including animals, plants, mushrooms, and bacteria.
3.1 Abiotic Factor
Any nonliving part of the environment, such as sunlight, heat, precipitation, humidity, wind or water currents, soil type, and so on.
Organisms that capture energy from sunlight or chemicals and convert it into forms that living cells can use. Autotrophs use solar or chemical energy to produce "food" by assembling inorganic compounds into complex organic molecules.
3.2 Primary Producer
The first producers of energy-rich compounds that are later used by other organisms.
Primary producers use photosynthesis to harness solar energy. Photosynthesis captures light energy and uses it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches.
Process in which chemical energy is used to produce carbohydrates. Used in places without sunlight.
Organisms that cannot directly harness energy from the environment (unlike primary producers). Ex. Animals, fungi and many bacteria
Organisms that rely on other organisms for energy and nutrients.
They kill and eat other animals. Include snakes, dogs, and cats.
They obtain energy and nutrients by eating plant leaves, roots, seeds, or fruits.
Animals that consume the carcasses of other animals that have been killed by predators or have died of other causes. (Ex. Vulture)
Animals whose diets naturally include a variety of different that usually include both plants and animals.
Such as bacteria and fungi "feed" by chemically breaking down organic matter. The decay caused by decomposers is part of the process that produces detritus - small pieces of dead and decaying plant and animal remains.
They feed on detritus particles, often chewing or grinding them into smaller pieces. (Ex. giant earthworms, snails, mites, shrimp, and crabs)
3.3 Food Chain
A series of steps in which organisms transfer energy by eating and being eaten
In some aquatic food chains, primary producers are a mixture of floating algae and attached algae called phytoplankton.
3.3 Food Web
A system of interlocking and interdependent food chains.
Krill are one example of a diverse group of small, swimming animals called zooplankton that feed on marine algae.
3.3 Trophic Level
Each step in a food chain or food web. Primary producers always make up the first trophic.
3.3 Ecological Pyramid
They show the relative amount of energy or matter contained within each trophic level in a given food chain or food web. 3 different types = pyramids of energy, pyramids of biomass, and pyramids of numbers.
The total amount of living tissue within a given trophic level.
The total of all the genetically based variation in all organisms in the biosphere. Biological diversity.
6.3 Ecosystem Diversity
The variety of habits, communities, and ecological processes in the biosphere.
6.3 Species Diversity
The number of different species in the biosphere , or in a particular area.
6.3 Genetic Diversity
The sum total of all different forms of genetic information carried by a particular species, or by all organisms on Earth. Within each species, it refers to the total of all different forms of genes present in that species.
6.3 Habitat Fragmentation
the process by which habitat loss results in the division of large, continuous habitats into smaller, more isolated remnants. Development often splits ecosystems into tiny pieces.
6.3 Ecological Hot Spot
A place where significant numbers of species and habitats are in immediate danger of extinction.
5.1 Population Density
The number of individuals per unit area.
5.1 Age Structure
The number of males and females of each age a population contains.
A population may grow if individuals move into its range from elsewhere.
A population may decrease in size if individuals move out of the population's range.
5.1 Exponential Growth
The larger a population gets, the faster it grows. Under ideal conditions with unlimited resources, a population will grow exponentially.
5.1 Logistic Growth
Occurs when a population's growth slows and then stops, following a period of exponential growth.
5.1 Carrying Capacity
The maximum number of individuals of a particular species that a particular environment can support.
5.2 Limiting Factor
In the context of populations, it is a factor that controls the growth of a population. Limiting factors determine the carrying capacity of an environment for a species.
5.2 Density-Dependent Limiting Factors
They operate strongly only when population density - the number of organisms per unit area - reaches a certain level. Ex) competition, predation, herbivory, parasitism, disease, and stress from overcrowding.
5.2 Density-Independent Limiting Factors
They affect all populations in similar ways, regardless of population size and density. Ex) Hurricanes, droughts, or floods, and natural disasters such as wildfires.
Every species has its own range of tolerance, the ability to survive and reproduce under a range of environmental circumstances
The general place where an organism lives
Describes not only what an organism does, but also how it interacts with biotic and abiotic factors in the environment. The range of physical and biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce.
Any necessity of life, such as water, nutrients, light, food or space. Ex for plants: sunlight water soil. Ex animals: nesting space, shelter, types of food, and places to feed.
4.2 Competitive Exclusion Principle
States that no two species can occupy exactly the same niche in exactly the same habitat at exactly the same time. If two species attempt to occupy the same niche, one species will be better at competing for limited resources and will eventually exclude the other species.
An interaction in which one animal (the predator) captures and feeds on another animal (the prey).
An interaction in which one animal (the herbivore) feeds on producers (such as plants).
4.2 Keystone Species
A species whose population changes that cause dramatic changes in the structure of a community
Any relationship in which two species live closely together. Biologists recognize the three main classes of symbiotic relationships in nature: mutualism, parasitism, and commensalism.
A kind of relationship in which both organisms benefit.
Relationships in which one organism lives inside or on another organism and harms it.
A relationship in which one organism benefits and the other is neither helped nor harmed.
4.3 Ecological Succession
A series of more-or-less predictable changes that occur in a community over time.
4.3 Primary Succession
Succession that begins in an area with no remnants of an older community.
4.3 Pioneer Species
The first species to colonize barren areas.
4.3 Secondary Succession
Where a disturbance affects the community without completely destroying it, secondary succession occurs. Often follows a wildfire, hurricane or other natural disturbance.