AP Biology Unit 8 Ecology

Vocab from Unit 8 (Ecology) of AP Biology. Created by using the AP Biology Princeton Review 2017 edition as a guide.

Net Primary Productivity

This is the amount of new organic matter produced by primary producers in an area over a specific time, representing the energy available for other organisms in the ecosystem

Vestigial Structure

a reduced or non-functional remnant of a structure that was once functional in an ancestor.

Instinct

This is an inborn, unlearned behavior. Sometimes it is triggered by environmental signals called releasers, which is usually part of the environment.

Fixed Action Pattern

This is a series of instinctive, genetically programmed behaviors that an animal performs when triggered by a specific sign stimulus. Once initiated, it continues to completion, even if the triggering stimulus is removed. These patterns are stereotyped, meaning they are highly predictable and consistent across individuals of a species.

Imprinting

Animals undergo BLANK within a few days after birth in order to recognize members of their own species. All types (parent, sexual, or song) all occur during a critical period - a window of time when the animal is sensitive to certain aspects of the environment.

Classical Conditioning

is an involuntary learning process where an association is formed between two stimuli, leading to a learned response. It involves pairing a neutral stimulus with a stimulus that naturally elicits a response, resulting in the neutral stimulus eventually triggering the same response.

ex. Ivan Pavlov and his dawgs

Operant Conditioning

In this learning, an animal voluntarily learns to perform an act in order to receive a reward. (Studied intensively by B. F. Skinner and rats). If the behavior is not reinforced, it will be lost, called extinction.

Habituation

This is another form of learning. IT occurs when an animal learns not to respond to a stimulus. For example, if an animal encounters a stimulus over and over again without any consequences, the response to it will gradually lessen and may disappear.

Insight

This is the highest form of learning and is exercised only by higher animals. It means the ability to figure out a behavior that generates a desired outcome. It involves using problem solving and reasoning.

Circadian Rhythm

These are internal clocks / cycles that act on a daily cycle. They are not based on things like sunlight

Pheromones

These are chemical signals between members of the same species that stimulate olfactory receptors and ultimately affect behavior.

Agonistic

This is aggressive behavior that occurs as a result of competition for food and other resources.

Dominance Hierarchies

These occur when members in a group have established which members are the most dominant. The more dominant male will often become the leader of the group and will usually have the best pickings of the food and females in the group. Once the order is established, competition and tension within the group is reduced.

Territoriality

This is a common behavior when food and nesting sites are in short supply, Usually, the male of the species will establish and defend his territory (called a home range) within a group in order to protect important resources.

Altruistic Behavior

This is defined as unselfish behavior that benefits another organism in the group at the individual’s expense because it advances the genes of the group.

Photoperiodism

Plants flower in response to changes in the amount of daylight and darkness. They flower according to the amount of uninterrupted darkness.

Tropism

Turning in response to a stimulus

Photoropism

Refers to how plants respond to sunlight. Ex. bending towards light

Gravitropism

refers to how plants respond to gravity. Stems exhibit negative gravitropism (grow up, away from the pull of gravity) whereas roots exhibit positive gravitropism (they grow downwards into the earth).

Thigmotropism

This refers to how plants respond to touch. Ex: ivy grows around a post.

Biosphere

The entire part of the earth where living things exist. This includes soil, water, light, and air. In comparison to the overall mass of the earth, it is relatively small.

It can be divided into large regions called biomes, which are massive areas that are classified by their climates and plant life.

• Tundra

• Taiga

• Temperate Deciduous Forest

• Grasslands

• Deserts

• Tropical Rain Forest

Ecosystem

The interaction of living and nonliving things.

Community

A group of populations interacting in the same area.

Population

A group of individuals that belong to the same species that are interbreeding.

Tundra

A biome

• - few plant life, contains permafrost (permanently frozen soil), short growing season, animals include: lemmings, arctic foxes, snowy owls, caribou, reindeer.

Taiga

A biome

• - wind-blown conifers (evergreens), stunted in growth, possess modified spikes for leaves. Very cold, long winters. Animals include caribou, wolves, moose, bear, rabbits, and lynx

Temperate Deciduous Forest

A biome

• deciduous trees that drop their leaves in winter, moderate precipitation; warm summers, cold winters. Animals: deer, wolves, bear, small mammals, birds

Grasslands

A biome

• Plant life: grasses.

• Characteristics: hot summers, cold winters, unpredictable rainfall

• Animal: prairie dogs, bison, foxes, ferrets, grouse, snakes, lizards

Deserts

A biome

• plant life: sparse, includes cacti and drought-resistant plants

• Characteristics: arid, low rainfall; extreme diurnal temperature shifts

• Animals: jackrabbits, owls, kangaroo rats, lizards, snakes, tortoises

Tropical Rainforest

A biome

• Plants: high biomass; diverse types

• Characteristics: high rainfall and temperatures; impoverished soil

• Animal: sloths, snakes, monkeys, birds, leopards, insects.

Gross Productivity

This is the entire photosynthetic production of organic compounds in an ecosystem. This cannot be measured directly, because photosynthesis and cell respiration occur simultaneously.

Net Productivity

This only measures organic materials that are left over after photosynthetic organisms have taken care of their own cellular energy needs. This is calculated by measuring oxygen production in the light, when photosynthesis and cell respiration are both occurring.

Niche

the specific role and position a species occupies within its ecosystem, encompassing its environmental conditions, resources, and interactions with other species

Density-Independent Factors

These are factors that affect the population, regardless of the density of the population. Ex: severe storms, extreme climates.

Density-Dependent Factors

These are factors whose effect depend on population density. Examples include resource depletion, competition, and predation.

R-Strategists

These, like many insects and weeds, are adapted to unstable environments and prioritize rapid reproduction with many offspring, often at the expense of individual survival

K-Strategists

These, like elephants, are adapted to stable environments and invest more in fewer offspring, enhancing their chances of survival.

Ecological Succession

the process by which a biological community changes over time, gradually replacing existing species with new ones over a relatively short period of time (decades or centuries).

Primary Succession

This is the process of ecological succession in which no previous organisms have existed.

Secondary Succession

When a new community develops where another community has been destroyed or disrupted.