bio semester 2 review

ecology

the study of interactions among organisms and their environment, involving both living (biotic) and non-living (abiotic) components

niche

“role” that an organism occupies in an ecosystem

ecological levels of organization

ecological hierarchy including species, population, community, ecosystem, biome, and biosphere

species

organisms that are naturally able to reproduce to make viable fertile offspring

population

a group of individuals of the same species living in a specific area

community

all the different populations that live together in an area and interact with each other

ecosystem

a community of living organisms interacting with their physical environment, including both biotic and abiotic factors

biome

a large geographic area characterized by specific climate conditions and distinct plant and animal species

biosphere

the global sum of all ecosystems; the zones of life on Earth; where all life can exist

photosynthesis

the process by which green plants and some other organisms (algae, phytoplankton, etc.) convert light energy into “stored chemical energy” in the form of glucose and other organic biomolecules

chemosynthesis

the process by which bacteria use chemical energy to produce “stored chemical energy” in the form of organic biomolecules

photoautotrophs

organisms that use sunlight as their energy source to convert carbon dioxide into glucose and other biomolecules

chemoautotrophs

organisms that derive energy from inorganic compounds to synthesize organic biomolecules

heterotroph

organisms that cannot produce their own food and must obtain energy by consuming other organisms

herbivore

an organism that primarily consumes plants, plant products, or other photoautotrophs

carnivore

an animal (or other organism) that primarily eats other animals (or organisms); does not consume produces

omnivore

an organism that consumes both plants and animals in a food web (acts as either a herbivore OR carnivore in a particular food chain)

detritivore

an organism that consumes rotting organic matter, breaking it down into smaller pieces

decomposer

organisms that break down dead organic matter, recycling nutrients back into the ecosystem. (not technically a feeding style) (aren’t typically included in food webs even though they are there to decompose an organism that dies)

food chain

a linear sequence showcasing the feeding relationships between organisms in an ecosystem, producer → primary consumer → secondary consumer → etc

food web

a complex network of interrelated food chains within an ecosystem, illustrating energy transfer through trophic levels; follow arrows from producer to top consumer to count food chains

apex predator

an organism that occupies the highest trophic level; “top of the food chain”; may not have predators above them

keystone species

species that have great influence on an ecosystem; said to “hold/glue the ecosystem together”; can be (but doesn’t have to be) an apex predator

trophic level

each step of a food chain, from producer to top consumer; designated as 1st, 2nd, 3rd, 4th, 5th, etc.

producer

an organism that produces its own food, typically through photosynthesis or chemosynthesis, serving as the basis of food webs in an ecosystem

consumer

an organism that obtains energy by consuming other organisms (heterotrophs); includes herbivores, carnivores, and omnivores

primary consumer (1^o)

organisms that consume producers; typically herbivores

secondary consumer (2^o)

organisms that consume primary consumers (consume the herbivores)

tertiary consumer (3^o)

organisms that consume secondary consumers; can be a top predator in a food chain

quaternary consumer (4^o)

organisms that consume tertiary consumers; typically an apex predator in a food web (may also take on the niche of a keystone species)

energy transfer

the process of energy passing via consumption (biomolecules) from one trophic level to another, typically with a 10% efficiency (is inefficient); gets “lost” as metabolic waste; heat, egested waste, and CO2 (product of cell respiration)

energy transfer calculation

to find energy available to the next trophic level, multiply the energy of the previous level by 10% (0.1); there are 1,000 calories (cal) in 1 kilocalorie (kcal)

mutualism

where both species benefit from the relationship (+/+)

parasitism & parasitoids

where one organism benefits at the expense of another (+/-); parasites generally don’t kill their host, parasitoids do

commensalism

where one organism benefits while the other is unaffected (+/0)

amensalism

where one organism is unaffected while the other is inhibited or destroyed (0/-) *not true symbiosis

binomial nomenclature

a standardized system for naming species using two terms: the genus name (capitalized) and the species identifier (lowercase), both italicized or underlined

importance of binomial nomenclature

avoids confusion caused by common names, which can vary by region and language, thus providing a universal standard for species identification; scientific names

problems with common names

they can be misleading, refer to multiple species, or be too general; scientific names are preferable, as they are universal

phylogeny

the inferred evolutionary history and relationships among individuals or groups of organisms

protista

super diverse kingdom of life that includes mostly unicellular eukaryotic organisms, with some multicellular forms, often found in aquatic environments

fungi

a kingdom that includes multicellular and unicellular organisms that absorb nutrients through external digestion. key members are molds, yeasts, and mushrooms; can act as decomposers, parasites, etc.

plants

a kingdom of multicellular, eukaryotic, producers that use photosynthesis to generate biochemicals (sugars); “photoautotrophs”

animals

a kingdom of multicellular and eukaryotic organisms that are heterotrophic (consume food) and often possess complex organ systems for various functions

archaebacteria

a kingdom of single-celled prokaryotes (“ancient bacteria”); they often thrive in extreme environments like hot springs and salt lakes

eubacteria

a kingdom of prokaryotic single-celled “true bacteria” prokaryotic cells; can be found in a variety of environments