AP Bio Unit 8: Ecology

The best quiz ever

Population

The same species within a given area

At what level does evolution work?

The population level

Community

A collection of populations in an area that interact with one another

Ecosystem

Multiple communities, as well as abiotic factors

Biosphere

All ecosystems on Earth, as well as air and water currents

Phenotypic plasticity

Organisms altering phenotypes (navigating long distances, biological clock)

Phenotype

How an organism behaves

Kinesis

RANDOM movement (like bacteria experiencing salty water) (wowie that feels yucky!)

Taxis

INTENTIONAL movement (like prey running from a predator) (ahhh!)

Phototropism

Hormones in stems make plants grow towards the sun

Auxin

Type of hormone that builds up on the shady side of the stem and causes the plant to grow towards light

Photoperiod

Number of sunlit hours during the day

Plants that flower in Winter

Short day plants

Plants that flower in Summer

Long day plants

Why do birds rely on photoperiods?

Migration

What does the pineal gland do?

Release melatonin (zzzz)

Chemical signals

Used to attract mates and warn others of danger, also used by plants

Tactile/electrical signals

Touch, fish send electrical currents through water

Innate

Instinctive behavior (like courtship)

Learned

Experience in environment (crows ignoring a scarecrow)

Cooperative behavior

Behaviors improving another individual’s fitness (pack hunting, fish schooling)

Endotherms

Body temp is internal, mammals and birds

Ectotherms

Bodies generate heat from the sun, like plants

Metabolic rate

Number of calories burned at rest

What has a higher metabolic rate, endotherms or ectotherms?

Endotherms

Chemosynthesis

When plants obtain energy from chemical compounds to make sugars

Autotrophs

Photosynthesize/chemosynthesize

Heterotrophs

I eat you nom nom nom

Primary consumers

Herbivores

Secondary consumers

Carnivores

Tertiary consumers

Carnivores that eat the carnivores

How much of an individual is carbon

Carbon is 20% of the individual’s dry mass

Combustion

Transforms fossil fuels into CO2

Population size

Number of INDIVIDUALS in a given area

Population density

Number of individuals/size of area

Population distribution

How clumped individuals are in their geographic range

Population biological gender ratio (knowt said no profanity)

Ratio of males to females, usually ~50:50

dN/dt

rate of change in population size over time

dN/dt=N1-N0

Change from time 0 to time 1

Type 1 survivorship curve

High survival that declines sharply

Type 2 survival curve

Steadily declining survival

Type 3 survival curve

Sharp drop early, then steady decline

K-selected species

Slow reproduction, remain near environment carrying capacity (type 1 curve)

r-selected species

High reproduction and unstable environment (type 3 curve)

Density-Independent Factors

Population growth is reduced regardless of density (floods, tornadoes, fire)

Density-Dependent factors

Population growth is increasingly limited as size increases (competition)

Logistic Growth

Describes population growth when there is a density-dependent carrying capacity (if dn/dt=0, the population is stable)

Can a population exceed its carrying capacity?

Yes, then large die-offs when there are more individuals than food

Species richness

Number of species

Species evenness

number of individuals in each species

What makes a community diverse?

More species richness, but if they are equal then more evenness

How are terrestrial habitats organized?

Dominant plant life

How are aquatic habitats categorized?

Water type and salt level

Niche generalists

Live under a wide range of conditions

Niche specialists

Live under a narrow range of conditions

Coevolution

Adaptations to counteract evolved defenses (plants evolve thorns, so mammals evolve tougher teeth)

Intraspecific competition

Competition within one species

Keystone species

A species that may not be large in size but disproportionately impacts others

Direct effect

Presence of one species affecting another

Indirect effect

Presence of one species affecting another through intermediate species

Trophic cascade

Indirect effects from a predator that trigger a chain reaction going down the trophic levels

Fundamental niche

Where a species COULD occupy, mostly abiotic factors

Realized niche

Where a species actually DOES occupy, includes all abiotic and biotic factors (wow I just REALIZED the species actually lives here!)

Resource/niche partitioning

When two previously competitive species evolve to work around their problems (birds with different beak sizes eating different seed sizes)

Genetic diversity is determined by

Variety of phenotypes

High genetic diversity

Population can respond to changing environmental conditions

Can artificial selection be accidental?

Yes! Whoops just created a whole new species aha

What did Pangaea break up into?

Laurasia and Gondwana

Why is Australia’s vegetation so WACK?

Was isolated for longer after Pangaea split

Mass extinction is when

75% of existing species decline within 2 million years

ENSO

El Niño—Southern Oscillation: changes in air pressure change surface currents, causing drought and flooding for 1-2 years

What is the primary reason for species decline?

Habitat loss

Greenhouse gas examples

H2O, CO2, CH4, N2O

Competitive exclusion

When two species compete but evolution favors one (ruh roh)

What happens as N approaches K?

R and dN/dt decrease

Mimicry

When one species evolves a resemblance to another species to gain a survival advantage