science ecology

What do ecologists study?

The relationship between organisms and their environment and the balance between their relationships

ecosystem

all organisms and nonliving things in one place.

community

All the organisms in an ecosystem.

population

all the members of a species

Give an example of an abiotic and a biotic factor.

Abiotic: sunlight.

Biotic: plants

What is a trophic structure?

A pattern of feeding relationships consisting of several different levels.

Distinguish between a food chain and a food web.

Food chain: The sequence of food transferring up the trophic levels.

Food web: interconnected food chains; a more realistic view of trophic structure

Why does only 10% of the energy move up…?

The consumed level avoids being eaten; indigestible parts of organisms; energy used by organism itself for work.

What does the term biodiversity refer to…?

Variety of different kinds of organisms.

Give an example of intraspecific and interspecific competition.

Intraspecific: growing plants in a garden competing for nutrients and water.

Interspecific: chipmunks and squirrels competing for nuts.

How does resource partitioning reduce competition…?

Allows species to use a different set of resources.

batesian mimicry .

Batesian: harmless species mimics harmful one.

Ex: hawk moth larva puffs up and hisses like a snake

mullerian mimicry

two unpalatable species mimic each other.

Ex: bees and yellow jackets.

Give two predator adaptations

Using teeth for grasping prey, and smelling to locate vegetation/herbivores

What is meant by the term keystone species

Serves a more important role than other species. Ex: sea stars.

mutualism

both benefit

Commensalism

one benefits, other not affected

Parasitism:

parasite benefits, harms host.

Why do disturbances to ecosystems help a community…?

Kills weaker organisms, stronger survive; creates new habitats; recycles nutrients

primary succession vs secondary succesion

primary succession starts with rocks

Secondary: after disturbance but soil remains.

How does energy move and how does chemicals move

Energy flows through ecosystems; chemicals are recycled.

Water cycle: human impact?

Cutting down trees lowers transpiration; pumping out groundwater harms ecosystem.

Carbon cycle: how carbon is released and removed. Human impact?

Released: cellular respiration and fossil fuel burning.

Removed: photosynthesis

Human Impact: CO₂ increase, global warming.

Phosphorus cycle: how added and disrupted?

Weathering of rocks adds it.

Disrupted by sewage/fertilizer/pesticides.

Nitrogen cycle: why are bacteria vital?

They convert unusable nitrogen to usable forms.

Why do organisms need water, carbon, etc.?

Water for chemical reactions.

Carbon for glucose.

Phosphorus for DNA, bones.

Nitrogen for proteins and nucleic acids.

Overall, they are needed for survival.

Habitat destruction is the biggest threat to biodiversity. Why do we care about biodiversity being lost

Depend on other species for food, medicines, clothing, shelter, oxygen, soil fertility and ecosystem balance

Why can factory pollutants be a problem

Nitric and sulfuric acids → acid rain

Why can CFCs be a problem

deplete the ozone layer

why can excess nitrogen and phosphorus runoff from fertilizers be a problem

algae blooms

why can synthetic chemicals that dont break down be a problem

don’t break down; passed down.

why are invasive or introduced species a threat to biodiversity

They outcompete native species or prey on them

What is overexploitation?

Using something too much (e.g., overhunting).

What causes greenhouse effect and what problems?

burning of fossil fuels and deforestation which leads to the trapping of gases. Can lead to a temperature increase on earth.

Exponential growth

Development at an increasingly rapid rate in proportion to the growing total number or size when resources are unlimited.

Mosquitos- rapidly lay eggs

Logistic growth

Growth rate decreased with increasing number of individuals until it becomes zero when the population reaches carrying capacity due to limited resources.

Ex: giraffes- the growth rate decreases as population increases in areas.