BI303 - Exam 1

biome determination

temperature and precipitation

rain shadow effect

a phenomenon that occurs when a mountain range blocks rain-producing weather systems, creating a dry area on the downwind side.

lake effect snow

Snow created when cold air flows over relatively warm water then over cold land

elevation effect on biome

biomes shift as elevation changes

tropical rainforest

Temp: High year-round

Precipitation: High year-round

Soil: Weathered, acidic, poor in nutrients

Plants: Adaptations to tolerate shade or find light quickly and easy, many epiphytes, parasites, and carnivorous plants.

tropical seasonal forest

Temp: High year-round

Precip: Seasonal (wet and dry seasons)

Soil: richer and less acidic than rainforest soil

Plants: many trees drought-deciduous (lose their leaves during dry season)

tropical savanna

Temp: High year-round

Precip: seasonal (short wet and long dry)

Soil: Productive, impermeable subsoils trap water

Plants: Grass dominated, along with hardy, drought-deciduous trees

hot desert

Temp: mostly hot, but high seasonal daily variation

Precip: very low (sometimes none)

Soil: low in nutrients, alkaline, sometimes saline, covered in biocrusts

Plants: defended against heat, UV, and herbivory

temperate grassland

Temp: temperate (warm summers, cold winters)

Precip: variable (generally wetter in the summer)

Soil: deep and very fertile

Plants: grasses and herbs, adapted to tolerate/benefit from fire and grazing

temperate forest

Temp: temperate, seasonal (warm summers, cold/mild winters)

Precip: moderate

Soil: thick, fertile, and rich in organic matter

Plants: cold-deciduous trees, some conifers

temperate shrubland

Temp: temperate, seasonal (warm summers, cold to mild winters)

Precip: seasonal (dry summers, wet winters)

Soil: dry, compacted, low fertility

Plants: many shrubs, small trees; adapted to drought and fire

temperate rainforest

Temp: temperate, seasonal (cool summers, mild winters)

Precip: high (except during summer)

Soil: typically infertile

Plants: coniferous trees (including the largest on earths)

boreal forest

Temp: temperate, seasonal (warm summers, cold to mild winters)

Precip: moderate (but very little evaporation)

Soil: acidic, organic-rich, sometimes very thick and waterlogged

Plants: mostly evergreen conifers, deciduous trees, shrubs, fire-adapted

tundra

Temp: cold (subzero most of the year)

Precip: low (but little evaporation)

Soil: thick, defined by permafrost

Plants: moss, lichen, perennial grasses and herbs

Net Primary Productivity (NPP)

The energy captured by producers in an ecosystem minus the energy producers respire

Riparian area

areas of plants and trees that grow along the edges of rivers, streams and lakes. Can help prevent erosion and serve as filters for pollution.

allochthonous

where nutrients come from a terrestrial environment and enter into a river

Autochthonous

nutrients generated from WITHIN the river (algae, etc).

Lake "ingredients"

Water - from precipitation, snow/ice melt, rivers, and/or groundwater

A basin - formed by glaciers, tectonics, rivers, wind, karsts, volcanoes, animals, and/or humans

karsts

a type of landscape where the dissolving of the bedrock has created sinkholes, sinking streams, caves, springs, and other characteristic features

littoral zone (lake)

receives sunlight, near the shoreline, edge of the water

limnetic zone (lake)

receives sunlight that does not reach the bottom, high areas of photosynthesis

profundal zone (lake)

low levels of oxygen (anoxic), no producers, dominated by decomposers and predators

lake stratification

the layers of the lake that get mixed in turnover

meromitic

layers rarely mix

holomictic

layers mix at least once per year

monomictic

mixes once a year

dimitic

mixes twice a year

polymictic

mixes several times a year

oligotrophic

typically at a higher elevations and latitudes

Low in nutrients, low NPP, high oxygen levels

mesotrophic

wide distribution

Moderate nutrient levels, NPP dominated by plants, clear(ish) water, more tolerant fish to lower oxygenated water

eutrophic

found at lower latitudes and tend to be closer to humans

High nutrients, high NPP, low oxygen

Tend to be shallower and flat bottomed

Water clarity depends on dominant producers

eutrophication

human-caused influx of nutrients (higher concentration of nitrogen, water is almost anoxic)

→ The removal of herbivorous fish adds to eutrophication (less fish to graze on producer)

neritic zones

-lies over the continental shelf

-not very deep

-plenty of nutrients and sunlight

-many organisms

kelp forest distribution

mangrove distribution

along tropical shores with limited wave action, a subtle slope (for sediment build up), high rate of sedimentation, and soil that's waterlogged, anoxic (no oxygen), and a high salt content.

oceanic zone

vast open ocean from the edge of the continental shelf outward

open ocean biome

The depth that light can penetrate in the open ocean is dependent on the amount of sediment and algae suspended in the water.

mesopelagic

known as the twilight zone, faint light

hydrothermal vents

spots on the ocean floor where hot gases and minerals escape from earth's interior into the water

Chemoautotrophs

bacteria oxidize H2S from vents, form base of unique food web

evolution

change in allele frequencies in a population over time

genetic variation

Differences among individuals in the composition of their genes or other DNA segments

mutation

• Random changes to an allele (creating a new allele)

• Very rare

• Mostly neutral, or harmful, rarely beneficial

recombination

• Shuffling of alleles during sexual reproduction

• Creates new combinations of alleles (potentially, new phenotypes)

diversifying selection

a type of natural selection in which organisms with phenotypes at both extremes of the phenotypic range are favored by the environment

directional selection

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

stabilizing selection

Natural selection that favors intermediate variants by acting against extreme phenotypes

allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

parapatric speciation

speciation pattern in which populations speciate while in contact along a common border

co-evolution

Process by which two species evolve in response to changes in each other

phenotypic plasticity

the ability of an organism to change its phenotype in response to changes in the environment.

acclimation

an organism's change in response to a change in the organism's environment

developmental response

irreversible phenotypic change in response to environmental cues

reaction norms

show a genotype's change in phenotype across a range of environments

niche partitioning

natural division of resources based on competitive advantages

species distribution

areas of the world in which a species lives

niche

An organism's particular role in an ecosystem, or how it makes its living.

fundamental niche

environmental factors that permit a species to survive

• Defines conditions where a species might live, in the absence of interactions of other species

realized niche

the actual (observed) distribution of a species, as limited by ecological interactions such as competition, predation, disease and parasitism

allochrony

species using the same area or resource, but at different times (includes different mating seasons)

character displacement

Species evolve non-overlapping traits to avoid competition

extremophiles

species that have evolved to tolerate extreme conditions

homeotherms

Organisms that maintain a consistent body temperature

ectotherms

An animals that warms itself mainly by absorbing heat from its surroundings

poikilotherms

organisms that do not regulate their temperatures

food webs

A complex diagram representing the many energy pathways in an ecosystem

food chain

A series of steps in which organisms transfer energy by eating and being eaten

heterotrophs

An organism that obtains organic food molecules by eating other organisms or their by-products.

Photosynthetically Active Radiation (PAR)

wavelengths of light between 400 and 700 nm that photosynthetic organisms use as a source of energy

herbivores

Consumers that eat only plants

omnivores

eat both plants and animals

carnivores

Consumers that eat only animals

trophic levels

levels of nourishment in a food chain

10% rule

Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.

optimal foraging

theory that states that natural selection will favor organisms that have behaviors that can gather the best food sources

OPT equation

(E/H+S)

nutritional ecology

the science of relating an animal to its environment through nutritional interactions

nutrition remobilization

the process by which plants relocate nutrients from older tissues to developing tissues, especially during periods of stress or senescence

sexual selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.

asexual reproduction

Process by which a single parent reproduces by itself

isogamy

gametes are equal in size

(lower chance of fertility = allows for more offspring)

anisogamy

gametes are different in size, usually in the form of a larger egg

(higher chance of fertilization = less offspring)

gonochorism

a sexual system where each organism in a species is either male or female

Hermaphroditism

A condition in which an individual has both female and male gonads and functions as both a male and female in sexual reproduction by producing both sperm and eggs.

sexual dimorphism

Differences in physical characteristics between males and females of the same species.

intersexual selection

individuals of one sex are choosy in selecting their mates from the other sex (AKA mate choice)

intrasexual selection

A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex.

monogamy

pair bonding between a male and female, which exclusively mate with one another, raise offspring together and spend time together

polygamy

an organism may have multiple mating partners (polyandry and polygyny)

promiscuity

when multiple males and females mate with each other without forming pair bonds.

polygyny

a male will mate with several females

polyandry

a female will mate with several males

sociality

the preference for living in groups and interacting regularly with members of the same species

solitary

independent except for when mating

subsocial

mates and cares for own offspring but doesn't associate with other adults

parasocial

Co-habitate (live together) but care mostly for own young or related young

eusocial

organism population in which the role of each organism is specialized and not all of the organisms will reproduce

altruism

an individual will put themselves at risk of danger for the welfare of the rest of the pack (alarm calls, self-sacrifice, alloparenting)

Hamilton's rule of fitness

rB > C