ib topic 2

What is ecology?

The branch of biology that studies how organisms interact with their environment and other organisms.

What defines a species?

A group of organisms sharing common characteristics that can interbreed and produce fertile offspring.

What is a population?

A group of the same species living in the same area at the same time, which are capable of interbreeding.

What is a habitat?

The environment in which a species normally lives.

What is a niche?

A particular set of abiotic and biotic conditions and resources to which an organism or population responds.

What is a fundamental niche?

The full range of conditions and resources in which a species could potentially survive and reproduce.

What is a realized niche?

The actual conditions and resources in which a species exists due to biotic interactions such as competition.

What are abiotic factors?

Non-living, physical factors that influence organisms and ecosystems.

What are biotic factors?

Interactions between organisms, such as predation, disease, and competition.

What are the factors affecting population size?

Birth rates, mortality (death rates), and migration.

What is immigration?

The movement of individuals into a population.

What is emigration?

The movement of individuals out of a population.

What is solar radiation?

Energy that enters Earth's atmosphere, some of which becomes unavailable due to absorption or reflection.

What is photosynthesis?

The process of converting light energy into chemical energy.

What is biomass?

The living mass of an organism, typically measured in dry mass.

What is GPP (Gross Primary Productivity)?

Total energy/biomass fixed by producers.

What is NPP (Net Primary Productivity)?

GPP minus respiration; the energy available to the next trophic level.

What is GSP (Gross Secondary Productivity)?

Total energy assimilated by consumers.

What is NSP (Net Secondary Productivity)?

GSP minus respiration; the energy available to secondary consumers.

What is carrying capacity (K)?

The maximum number of individuals that an environment can sustainably support.

What are limiting factors?

Resources such as food, water, and space that slow population growth as it approaches K.

What is competition in ecology?

The struggle between organisms for the same resources.

What is the difference between intraspecific and interspecific competition?

Intraspecific competition occurs between members of the same species, while interspecific competition occurs between different species.

What is symbiosis?

A close interaction between two different species.

What is parasitism?

A symbiotic relationship where one organism benefits and the other is harmed.

What is mutualism?

A symbiotic relationship where both species benefit.

What does an S-curve (sigmoid) show?

It shows exponential growth followed by a slowdown as the population reaches carrying capacity.

What does a J-curve show?

It shows exponential growth that often leads to an overshoot of carrying capacity followed by a die-back.

What is nitrogen fixation?

The process that makes N_2 gas from the atmosphere available to plants.

What is nitrification?

The process by which bacteria convert ammonium into nitrites and nitrates.

What is assimilation in the nitrogen cycle?

The uptake of nitrogen by living organisms to build proteins and DNA.

What is ammonification?

The process by which decomposers turn organic nitrogen back into ammonium.

What is denitrification?

The process by which bacteria convert nitrates back into N_2 gas.

What are the storages in the carbon cycle?

Fossil fuels, soil, oceans, atmosphere, and organisms.

What are the flows in the carbon cycle?

Photosynthesis (carbon in) and Respiration/Combustion (carbon out).

What is eutrophication?

The process where excess nitrates lead to algae blooms, oxygen depletion, and fish kills.