ECO ch 4 + 5

What is a population?

A group of individuals of the same species living in the same area.

How do we measure population change?

Births + immigration − deaths − emigration.

What is the Mark and Recapture method?

A technique used to estimate population size by capturing, marking, releasing, and recapturing individuals.

Why do scientists use Mark and Recapture?

To estimate the size of animal populations that are difficult to count directly.

What are the three population distribution patterns?

Clumped, Uniform, Random.

What is a life table?

A table showing survival and reproductive rates at different ages.

What is a survivorship curve?

A graph showing how many individuals survive at different ages.

What are the three types of survivorship curves?

Type I (humans), Type II (birds), Type III (fish and insects).

What is exponential growth?

Rapid population growth under ideal conditions, creating a J-shaped curve.

What is logistic growth?

Population growth that slows as resources become limited, creating an S-shaped curve.

What is carrying capacity?

The maximum population size an environment can support over time.

What happens when a population reaches carrying capacity?

Growth slows or stops because resources become limited.

What are r-selected species?

Species that produce many offspring, provide little parental care, mature quickly, and have short lifespans.

Examples of r-selected species?

Rats, insects, weeds.

What are K-selected species?

Species that produce few offspring, provide extensive parental care, mature slowly, and live longer.

Examples of K-selected species?

Humans, elephants, whales.

What is the current global population?

About 8 billion people.

Where do most people live?

Asia.

What type of growth has the human population shown historically?

Exponential growth.

What is age structure?

The distribution of individuals among age groups in a population.

Why is age structure important?

It helps predict future population growth.

What does a population with many young people suggest?

Future population growth.

How can countries lower fertility rates?

Education, healthcare access, family planning, and increased opportunities for women.

Do more people live in cities or rural areas today?

Cities.

What are sustainable benefits of urban density?

Less land use, better public transportation, lower energy use, and more efficient services.

What is a community?

All populations of different species living in the same area.

What is community ecology?

The study of interactions among populations in a community.

What is a predator-prey relationship?

One organism hunts and consumes another.

What is an evolutionary arms race?

Continuous adaptations between predators and prey.

Examples of predator-prey adaptations?

Camouflage, mimicry, poison, venom.

What is mimicry?

When one species resembles another species for protection.

What is herbivory?

Animals feeding on plants.

What are mechanical plant defenses?

Thorns, spines, and other physical defenses.

What are chemical plant defenses?

Toxins and chemicals that deter herbivores.

What is the Competitive Exclusion Principle?

Two species cannot occupy the same niche indefinitely if resources are limited.

What is symbiosis?

A close, long-term relationship between different species.

What is mutualism?

Both species benefit (+/+).

What is commensalism?

One species benefits while the other is unaffected (+/0).

What is parasitism?

One species benefits while the other is harmed (+/-).

What is biodiversity?

The variety of life in an ecosystem.

What is species richness?

The number of different species in an area.

What is relative abundance?

The proportion of each species in a community.

What is a foundation species?

A species that creates or maintains habitat for other species.

What is a keystone species?

A species with a disproportionately large effect on its ecosystem.

What is a famous keystone species example?

Wolves in Yellowstone National Park.

What is an invasive species?

A non-native species that spreads and causes ecological harm.

Examples of invasive species?

Zebra mussels and kudzu.

Why are invasive species harmful?

They outcompete native species and disrupt ecosystems.

What is succession?

The gradual change in community composition over time after a disturbance.

What is primary succession?

Succession beginning on bare rock with no soil.

Example of primary succession?

New land formed by volcanic activity.

What is secondary succession?

Succession after a disturbance where soil remains.

Examples of secondary succession?

Forest fires, hurricanes, abandoned farmland.

What is an ecological footprint?

The amount of land and resources needed to support a person's lifestyle.

What is sustainable yield?

The amount of a resource that can be harvested without reducing future availability.

What are some interesting facts about male bees (drones)?

Their main job is mating with the queen. They do not collect pollen and cannot sting.

What are some interesting facts about queen bees?

They are the primary reproductive female and can lay thousands of eggs.

What are some interesting facts about honey?

It is made from nectar, stores energy for bees, and can last for years without spoiling.

What substances do bees make?

Honey, beeswax, propolis, and royal jelly.

What is honey used for?

Food storage.

What is beeswax used for?

Building honeycomb.

What is propolis used for?

Sealing and protecting the hive.

What is royal jelly used for?

Developing queen bees.

What are Africanized ('killer') bees?

A hybrid bee known for being more aggressive and defensive.

Why are pollinators dying off?

Habitat loss, pesticides, disease, parasites, and climate change.

What are common bee pests?

Varroa mites, small hive beetles, and wax moths.

What is taxonomy?

The science of classifying organisms based on morphology and genetics.

What is the broadest taxonomic category?

Domain.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

What are bacteria?

Microscopic, single-celled prokaryotes.

What are archaea?

Single-celled prokaryotes genetically different from bacteria.

What are extremophiles?

Organisms that live in extreme environments.

What organisms belong to Eukarya?

Animals, plants, fungi, and protists.

What are the four kingdoms?

Animalia, Plantae, Fungi, and Protista.

What is an autotroph?

An organism that makes its own food.

What is a heterotroph?

An organism that obtains energy by consuming other organisms.

What domain does E. coli belong to?

Bacteria.

What domain do methanogens belong to?

Archaea.

What domain do animals belong to?

Eukarya.

What explains the diversity of life on Earth?

Evolution through natural selection.

Who developed the theory of evolution by natural selection?

Charles Darwin and Alfred Russel Wallace.

What is natural selection?

The process where individuals with beneficial traits survive and reproduce more successfully.

What is required for natural selection to occur?

Variation among individuals.

What happens to beneficial traits over time?

They become more common.

What happens to harmful traits over time?

They become less common.

How long has life been evolving on Earth?

Billions of years.

What are the main principles of natural selection?

Variation, inheritance, overproduction of offspring, and differential survival/reproduction.

What is an example of evolution happening today?

Antibiotic resistance.

Another example of evolution today?

Pesticide resistance.

What is genetic diversity?

Variation in genes within a species.

What is ecosystem diversity?

Variety of ecosystems in a region.

What is biogeography?

The study of where species are distributed around the world.

Why is biodiversity important for human health?

Many medicines come from living organisms.

Why is biodiversity important for agriculture?

It provides pollinators, pest control, and crop diversity.

What is the intrinsic value of biodiversity?

Species have value simply because they exist.

What is the aesthetic value of biodiversity?

Nature provides beauty and recreation.

What are the major causes of biodiversity loss?

Habitat loss, overharvesting, invasive species, pollution, and climate change.

What is overharvesting?

Removing organisms faster than populations can recover.

What is an endemic species?

A species found only in one geographic location.

What is the root cause of climate change?

Human greenhouse gas emissions, especially from fossil fuels.