HL BIO Y2 Ecology Study Guide

Species Definition

A group of organisms capable of interbreeding to produce fertile offspring.

Population definition

A group of organisms of the same species living in the same place at the same time.

Community Definition

A group of species living in the same area.

Ecosystem Definition

A group of organisms living in the same place and the physical environment.

Biome Definition

A type of environment; can be distinguished by their characteristics.

Types of Biomes

NEEDS TO BE ADDED

Biosphere Definition

The Earth and all the organisms contained within.

Biotic Definition

A term describing anything living. Ex: plants, animals

Abiotic Definition

A term describing anything nonliving. Ex; rocks, soil, etc.

Autotroph Definition

An organism that produces its own food.

Heterotroph Definition

An organism that gets its food externally.

Mixotroph Definition

An organism that can either produce its own food or get its food externally.

Herbivore Definition

A consumer that only eats plants.

Omnivore Definition

A consumer that eats both plants and animals.

Carnivore Definition

A consumer that only eats animals.

Scavenger Definition

A consumer that feeds on dead animals. (ex vulture)

Detritivore Definition

A consumer that eats living material that is dead or decomposing (like dead leaves)

Saprotroph Definition

A consumer that eats dead animals using external digestion.

Types of Competition

Itraspecific and Interspecific competition

Intraspecific Competition Definition

Competition between individuals of the same species

Interspecific Competition Definition

Competition between members of different species.

Parasitism Definition

A relationship where one organism is benefited and one is harmed.

Commensalism Definition

A relationship where one organism is benefited and one is neither helped or harmed.

Mutualism Definition and one example

A relationship where both organisms are benefited. Ex Zooxanthellae and coral reefs

Relationship between Zooxanthellae and Coral Reefs

The coral reefs provide a protected environment for the Zooxanthellae as well as compounds they need for photosynthesis and the Zooxanthellae produce oxygen and help the coral reefs remove waste.

Predation Definition

A relationship where one animal feeds on another.

Herbivory Definition

A relationship where an animal feeds on plants.

Mesocosm Definition

An outdoor experiment that examines the natural environment under controlled conditions.

Chi-Square Test for Species Association

A test used to determine whether or not the presence of two species are related.

Quadrat Sampling definition

A type of sampling which uses a square area called a quadrat selected out of the total area and counts all organisms within this area. Multiple quadrats may be taken and are used to estimate the number of individuals in a population.

Food Chain Definition

A path of transfer of energy between organisms in a community.

Food Web Definition

The sum of all possible food chains in a community.

Trophic Level Definition and name of the first three trophic levels

Level of energy an organism possesses in a food chain. First trophic level is producer, followed by primary consumer, secondary consumer, etc.

Primary Consumer Definition

A consumer that receives its energy directly from the producer. (Eats producers)

Secondary Consumer Definition

A consumer that gets its energy from a primary consumer.

What is the 10% rule

The 10% rule states that at each trophic level, 90% of the energy is lost, often as heat from respiration or from the expenditure of energy.

Biomass Definition

The mass of living organisms in a place at any given time.

Limiting Factor Definition

Something that restricts population growth or population size of a species.

Zone of Tolerance Definition

The range of an environmental condition in which a species can live.

Zone of Stress Definition

The range of an environmental condition in which a species can survive but will have reduced reproductive success.

Zone of Intolerance Definition

The range of an environmental condition in which a species cannot survive.

Niche Definition

The role a species plays in a community.

Fundamental Niche Definition

The entire set of conditions in which it is possible for a species to survive and reproduce.

Realized Niche Definition

The set of conditions in which a species actually lives.

Competitive Exclusion Principle Definition

Also known as Gause’s law, the competitive exclusion principle states that two species competing for the same limited resources cannot exist together at constant population values.

Keystone Species Definition

A species in an ecosystem that other species depend on. The removal of a keystone species from an ecosystem would cause drastic changes to the ecosystem.

Primary Succession Definition

Succession in which organisms must build the new ecosystem from scratch, without even soil.

Secondary Succession Definition

Succession in which there is a small foundation for the species to build the new ecosystem with.

Productivity Definition

The amount of energy that a group of organisms (usually primary producers) produces.

Net Productivity Definition

The amount of energy gained in the form of biomass minus the amount of energy lost to metabolism and maintenance.

Gross Productivity Definition

The amount of energy that plants produce.

Respiration Definition

The influx of oxygen and exit of carbon dioxide through breathing that provides organisms with energy.

Closed System Definition

A system that cannot transfer energy to its surroundings.

Open System Definition

A system that can transfer energy to its surroundings. All living organisms are open systems.

Alien Species Definition

A species introduced to a non-native habitat, often through human introduction.

Invasive Species Definition

An alien species that causes ecological and economical damage.

Biological Control Definition

A predator, parasite or pathogen introduced to eliminate a pest species, often an alien species.

Bioaccumulation Definition

The accumulation of chemical substances through contaminated food that builds up within one trophic level.

Biomagnification Definition

A process where chemical contaminants build up throughout each trophic level.

DDT

An example of biomagnification that is sprayed on crops to kill mosquitoes but builds in waterways and is stored in fats.

Microplastic and Macroplastic Definition

A microplastic is a piece of plastic debris that is smaller than 1 mm and a macroplastic is a piece of plastic debris that is bigger than 1 mm.

Natality Definition

The birth rate of a population

Immigration definition

The number of a species that move into a population.

Mortality Definition

The death rate of a population.

Emigration Definition

The number of a species that leave a population.

Failure Example of a Biological Control Used to Stop Alien Species

Cane toads were introduced in Australia but became an invasive species themselves.

Success Example of a Biological Control Used to Stop Alien Species

Neochetina Weevils were introduced to eat the invasive water hyacinth plant.

How is carbon transferred into the atmosphere?

Through respiration and combustion

How is carbon transferred from the atmosphere into plants?

Through Photosynthesis

What greenhouse gas does a cow, a garbage dump, and a swamp all have in common?

Methane

How is dead matter converted to methane in anaerobic conditions?

Through methanogens, which are part of the domain archaea.

List of greenhouse gases

Carbon Dioxide, Methane, Nitrogen Oxides, and Water Vapor

Food Conversion Ratio and meaning

Weight of food intake divided by weight of animal. The lower the lowest number the more efficient it is.

Effects of the Greenhouse Effect and Climate Change

Increase in the frequency and severity of storms, alteration of rainfall patterns, raising sea level because of glaciers and ice caps melting, death of coral because of an increase in sea temperatures, and an increase in ocean acidity because of rising carbon dioxide levels.

Peat Definition

Dead moss and vegetation that absorbs carbon from the atmosphere.

What is transect sampling?

Transect sampling is a sampling method that measures how the distribution of a species changes in relation to a specific abiotic factor. Transects are not done randomly, but placed in relation to the abiotic factor. Ex: How does the distribution of plant species change as you move away from the shoreline?

Relative speeds of phosphorous and nitrogen cycles

The rate of turnover in the phosphorous cycle is much slower than that of the nitrogen cycle.

Name of two nitrogen fixing bacteria in the nitrogen cycle and their function

Rhizobium and Azobacter convert atmospheric nitrogen to ammonia.

Role of fertilizer in the phosphorus cycle

Phosphorus is mined and converted to artificial fertilizer, which is in such high demand that the phosphorus is running out.

Role of Mycorrhizal fungi in Phosphorus cycle

Mycorrhizal fungi solubilize the phosphorus, making it available to plants.

What is eutrophication and what effect does it have on ecosystems in the ocean?

Eutrophication is when the available nutrients increase in aquatic ecosystem, causing an increase in biological oxygen demand. This basically means more nutrients means more algae, bacteria, and dead algae, and this sucks the oxygen out of the water, driving away fish and increasing the BOD. It also decreases the biodiversity in the ecosystems. Also it increases toxins in the water, making it dangerous to drink or bathe in.

Explain A Sigmoid Curve With Regards to population ecology

A sigmoid curve is representative of population growth with limited resources. The population starts at steady growth, then has exponential growth, and then has grows less and less until it reaches the carrying capacity. There are 3 phases, the transitional phase, the exponential growth phase, and the plateau phase. In the Transitional place, N+I > M+E, in the Plateau Phase, N=I=E+M, and in the exponential phase, N=i is much greater than M+E

Explain a J Curve in Population Ecology

A J curve represents the exponential growth a population encounters when there are ample nutrients and other resources.

What is the edge effect?

The edge effect is where habitats are bled into by outside habitats. This sometimes has the effect of increasing biodiversity in some way, but usually leads to a decrease in biodiversity.

Indicator Species Definition

A species that can only survive in a small range of an environmental condition. The presence of an indicator species is used to evaluate the environmental conditions of an ecosystem.

Biotic Index Meaning

Calculated by the formula of the sum of n x a over N, the higher the biotic index is, the less pollution there is.

In-situ conservation definition and example

In-situ conservation is the conservation of wildlife inside their natural habitat. The main example is nature preserves.

Ex-situ conservation definition and examples

Ex-situ conservation is conservation of wildlife outside of its natural habitat. Examples include zoos, botanical gardens, and captive breeding programs.

What is the effect of island size on biodiversity

The greater the island size, the greater the biodiversity.

What is a wildlife corridor and what effect does it have on species in habitats?

A wildlife corridor is a protected area connecting two nature preserves or habitats