Ecology

Between 3.5-4.0 billion years ago Earliest organisms were prokaryotes found in stomatolites.

• Water vapor • CO • CO2 • H2 • N2 • H2O • S • HCl These chemicals were released by volcanic eruptions.

Abiotic synthesis of organic monomers It suggests that complex molecules formed from inorganic molecules in Earth’s primordial seas.

The chemical environment on primitive Earth They produced a variety of molecules associated with life.

How matter flows through an ecosystem They include processes like assimilation and release.

The amount of light energy converted into chemical energy by autotrophs It is a key measure of ecosystem productivity.

Net Productivity = Gross - amount consumed by respiration Gross productivity refers to total productivity.

• Depth of light penetration • Availability of nutrients Nitrogen and phosphorus are key limiting nutrients.

Excessive growth of photosynthetic organisms like algae due to nutrient runoff It often results from sewage runoff, particularly phosphorus.

• Primary Producers • Primary Consumers • Secondary Consumers • Tertiary Consumers • Detritivores Each level represents a different role in the food chain.

Linear flow chart of who eats whom Example: Grass → zebra → lion → vulture.

Species that have a disproportionate effect on its environment relative to its biomass Their presence is crucial for maintaining the structure of an ecosystem.

Amount of energy transferred from one trophic level to the next Only about 10% of productivity is transferred to the next level on average.

The length of a food chain is limited due to inefficiency of energy transfer It explains why food chains cannot be excessively long.

Warm-blooded organisms that use metabolism to regulate body temperature They maintain a constant internal temperature.

Cold-blooded organisms that lack internal regulatory mechanisms They rely on behavior to regulate body temperature.

body mass Generally, larger organisms have lower metabolic rates per unit of body mass.