AP Bio Unit 8

Ecology

Scientific study of interactions between different organisms and between organisms and their environment or surroundings

Biotic Factor

Living factors within an ecosystem. Includes dead things.

Abiotic Factor

Non-living factors within an ecosystem

Producers

(Autotrophs) Organisms that use solar energy to create their own food. Photosynthetic or Chemosynthetic

Consumers

(Heterotrophs) Organisms that eat other organisms for food

Herbivore

Organisms that only eat plants

Carnivore

Organisms that only eat meat

Omnivore

Organisms that eat both plants and meat

Decomposer

Organisms that break down dead organic matter

Organism

Single living thing

Population

All of the organisms in a species in a particular environment

Community

A community is a group of interacting populations that occupy the same area at the same time

Ecosystem

System of living things that interact with each other and the abiotic factors

Biome

Large naturally occurring community if flora and fauna occupying a major habitat

Biosphere

Collection of ecosystems and biomes of a planet

Food Chain

Series of steps in which organisms transfer energy by eating and being eaten

Food Web

Network of food chains within an ecosystem

Primary Producers

Autotrophs, support all other organisms in the ecosystem like plants, algae, photosynthetic organisms

Primary Consumers

Heterotrophs, example: herbivores that eat autotrophs

Secondary/Tertiary Consumers

Heterotrophs, example: carnivores that eat herbivores or other carnivores

Biomass

Total dry mass of all the organisms in a given area, decreased as you move up the food chain/trophic levels

Endotherms

Use thermal energy produced by metabolism to maintain internal temperatures (warm-blooded) maintain a constant internal temperature and require more energy

Ectotherms

Regulate internal temperatures by body movement, sun, or other sources (cold-blooded), rely on environmental heat sources, using less energy

Biodiversity

The amount of variation of species within an ecosystem. Higher Biodiversity = More Biomass

Ecological Niche

A role the species plays, includes the type of food it eats, where it lives, here it reproduces, and its relationship with other species

Survivorship Curves

Graph showing the number or proportion of individuals surviving to each age for a given species or group

Type 1 Curve

Organisms with Low Death Rates, in young middle age, high in old age. Example: Humans

Type 2 Curve

Constant Death Rate. Example: Reptiles & Rodents

Type 3 Curve

High Death Rate in Young then constant rate

Clumped Population Dynamics

Most common; near required resource

Uniform Population Dynamics

Usually antagonistic interations

Random Population Dynamic

Unpredictable spacing, not common in nature

Taxis

Change in direction, automatic movement toward (positive taxis) or away from (negative taxis) a stimulus

Kinesis

Random movement, change in rate of movement in response to a stimulus

Kin Selection

When animals risk themselves to save family members

Altruistic behaviors

Increase fitness of genes in close replications

Symbiosis

Interaction between 2 or more organisms

Competitive exclusion Principle:

One with slight reproductive advantage will eliminate the other

Parasitism

Parasite takes nourishment the host

Mutualism

Both species benefit

Commensalism

One species benefit, other has no or very little affect

Keystone Species

Not abundant in a community, exert major control over other species in the community

Invasive Species

Non-native species that drastically alters food web and/or ecosystem

Gross Primary Production (GPP): Total Primary Production

Measurement of all producers in an ecosystem

Net Primary Production (NPP)

GPP minus energy used by primary producers from respiration (R), amount of energy that is transferred

Exponential Growth

Ideal conditions, population grows rapidly. Occurs rarely in nature

Limiting Factors

Elements that prevent a population from attaining its biotic potential

Carrying Capacity (K):

Maximum stable population which can be sustained by an environment

Logistic Growth

Slower growth that occurs closer to the carrying capacity (S-Shaped)

r-selected species

Species that exhibit rapid growth, where opportunistic species quickly invade habitats, reproduce, and die, eg: plants, insects

K-selected species

Species where population size remains constant and produce a small number of relatively large offspring that require much care until maturation

Competition

Interaction that occurs when individuals compete for a resource that limits their growth or survival

Competitive exclusion

The concept that when populations of two similar species compete for the same limited resources, one will have a reproductive advantage

Resource Partitioning

Division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors

Predation

Interaction between species in which one species, the predator, kills and eats the other, the prey

Symbiosis

An ecological relationship between organisms of two different species that live together in direct and intimate contact

Parasitism

A symbiotic interaction in which one organism, the parasite, derives its nourishment from another organism, its host (+/-)

Mutualism

An interspecific interaction that benefits both species (+/+)

Commensalism

An interaction between species that benefits one of the species but neither harms nor helps the other (+/0)

Species Diversity

A variety of different kinds of organisms that make up the community

Keystone Species

A species that exerts strong control on community structure not y numerical might but their pivotal ecological roles or niches

Invasive Species

Organisms (typically introduced by humans) that take hold outside their native range

Camouflage

Colors and patterns that enable an organism to blend into its environment to appear to be something it is not

Cryptic Coloration

Form of defense used by animals where they use coloration and patterns to blend with their environment, making them harder to be spotted by prey

Disruptive Coloration

Form of camouflage that works by breaking up the outlines of an animal a strong contrasting pattern, like the black and white stripes on zebras

Territorial Making

Animals use visual, audible, tactile, electrical and chemical signals to establish territory

Territory

An area defended by an individual/group of animals for several purposes (mating, nesting, feeding)

Mimicry

One organism looks like an organism of another species

Batesian Mimicry

Harmless species resembles poisonous species to intimidate and avoid predators

Mullerian mimcry

Two harmful or poisonous species evolve to resemble each other, reinforcing predator avoidance

Innate Behaviors

Genetically controlled and exhibited in nearly all individuals of a species

Fixed Action Patters

Sequences of unchangeable, instinctive behaviors triggered by a stimulus

Migration

Seasonal movement of animals, often influenced by environmental cues such as daylight and temperature

Signals and Communication

Organisms use different signals to convey information

Phototaxis

Movement in response to light

Chemotaxis

Movement in response to chemicals

Geotaxis

Movement in response to gravity

Imprinting

Learning that occurs during a critical period and is often irreversible

Spatial Learning

The ability to recognize landmarks to navigate the environment

Cognitive maps

Some animals create mental representations of their surroundings for navigation

Associative Learning

Learned by linking one stimulus with another

Social Learning

Learning by observing and imitating others

Foraging Behavior

Efficient food-seeking strategies increase an organism’s energy intake while minimizing risks

Sexual Dimorphism

Differences in appearance between males and females, often due to mating competition

Mating Systems

Include monogamy (one mate) and polygamy (multiple mates)

Altruism

Behaviors that benefit others at a personal cost

Phototropism

Growth in response to light, regulated by hormones like auxin

Photoperiodism

Changes in Physiological activity based on seasonal light availability

Physical Defenses

Thorns, bark and trichomes help protect plants from herbivores

Chemical Defenses

Plants produce toxins or distasteful compounds to deter predators

Soil Composition influence

Nutrient availability in soil affects plant growth and development, impacting ecosystem interactions

Water Cycle

Essential for life, involving evaporation, condensation, precipitation, and groundwater flow

Carbon Cycle

Moves carbon between the atmosphere, organisms, and fossil fuels, influencing climate change

Nitrogen Cycle

Converts atmospheric nitrogen into usable forms through fixation, assimilation, and decomposition

Phosphorus Cycle

Vital for DNA and ATP, cycles through rocks, water, and living organisms

Density-Dependent Factors

These are factors that have a greater effect on the population as its density (the number of individuals in a given area), Competition for resources, Predation, Disease, Parasitism

Density-Independent Factors

Factors that affect the population regardless of its density, Weather, natural disasters, human activities