Biology and society exam 1 (UMD)

Biology

the study of life and living organisms

Molecule

atoms bonded together

tissue

consists of specific types of cells organized in a specific pattern

organ

A collection of tissues that carry out a specialized function of the body

organ systems

set of interacting organs and tissues that fulfill one or more body functions

population

A group of individuals that belong to the same species and live in the same area

communities

different populations that live together in a defined area

ecosystems

A biological community of interacting organisms and their physical environment. through the transfer of energy and materials

biosphere

encompasses all regions of the earths crust, water and atmosphere in which organisms live

cellular basis

all living things consist of one or more cells

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

experimental group

the group in an experiment that receives the variable being tested

control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Inheritance

The process in which genetic material is passed from parents to their offspring.

photosynthesis

Plants use the sun's energy to convert water and carbon dioxide into sugars

error bars

can be used to indicate the amount of variation that exists around the average within the data set. they mark the highest and lowest valves in a data set

archaea

single celled, can be producers and consumers, most commonly related to eukaryotes

prokaryotes

single celled organism that do not contain nuclei

protist

common term for eukaryotes that is not a fungus, plant or animal. collectively protists vary dramatically, from single celled consumers to giant multi celled producers

gensus

a taxonomic group covering more than one species.

Taxonomy

the practice of naming, describing and classifying species

taxon

a group of organisms in a classification system

Scientific Method

forming a hypothesis based on observation, testing by hypothesis by evaluating predictions that flow from it, and making conclusions about the resulting data

sampling error

is a difference between results obtained from a subset, and results from the whole

statistical significance

how unlikely it is that an obtained result occurred by chance

psedoscience

a collection of beliefs or practices mistakenly regarded as being based on scientific method.

law of nature

generalization that describes a consistent natural phenomenon for which there is incomplete scientific explanation

biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

variable

characteristic that differs among individuals or overtime

ecology

the study of interactions among organisms and between organisms and their physical environment

population size

number of individuals of a species in a population

population density

is the number of individuals in some specified area or volume

population distribution

where individuals are relative to one another or how the population is spread out

clumped distribution

a distribution in which individuals are found in groups or patches within the habitat. can be caused by a patchy distribution of a essential resource

near-uniform distribution

competition for resources among members of a population that is evenly spread out

effects of scale and timing

the observed pattern of distribution can be influenced by scale of the area observed and the timing of observations

age structure

The distribution of ages individuals among various age categories. Affects the population's capacity for future growth.

per capita growth rate

the rate at which the population changes per individual in the population

exponential growth

describes how a population would change in size over time if its per capita growth rate was constant and its resources were unlimited. has a constant per capita growth rate

density dependent limiting factor

In dense populations, as their population size increases, birth rates can slow and death rates can rise. Can be caused by disease or competition.

intraspecific competition

competition among members of the same species is one of the density-dependent limiting factors that limit population growth

logistic model of population growth

describes how population growth changes as the size of the population approaches carrying capacity

density-independent limiting factors

a volcanic eruption, hurricane, flood, or oil spills can decrease the size of a population

biotic potential

the maximum growth rate for a species under ideal conditions

life history traits

this determines biotic potential, which are a set of heritable traits such as average rate of growth, age at first reproduction, etc

cohort

group of individuals that are all born at the same time interval

survivorship curve

shows information about age specific death rates, a plot that shows how members of a cohort remain alive overtime

opportunistic life history

when a species lives in unpredictable conditions, which creates populations seldom reach carrying capacity so there's little competition for resources. this causes a species to create as many offspring as possible

equilibrial life history

stable environments can cause parents to produce few, high quality offspring more commonly

total fertility rate

average number of children women of that population produce over the course of their child bearing years

Demographic Transition Model

4 stages of high birth and death rates leading to slow growth, falling death rates leading to faster growth, falling birth rates slowing growth, and both rates reaching a low level, slowing growth to zero.

ecological footprint

the amount of earths surface required to support a particular level of development and resource consumption in a sustainable fashion

parental investment

resources that an individual uses to reproduce that it would otherwise use for growth and maintenance

range

the total geographic area occupied by all populations of a species

plot sampling

use direct counts in marked area to estimate total number of individuals in a larger area

indirect counts

mark recapture sampling (used to study mobile animals)

niche

every species unique ecological role in a habitat. ex: temp it can tolerate, the kind of foods in can eat, etc

interspecific competition

competition between members of different species.

principle of competitive exclusion

species that require the same limited resources and access them in the same way cannot coexist indefinitely.

resource partitioning

an evolutionary process in which traits of two species that compete for a limited resource differ so that it minimizes commotion

warning coloration

is a conspicuous pattern of color that predators learn to avoid

mimicry

an evolutionary pattern in which species come to a resemble one another

Symbiosis

on interspecific interaction in which 2 species have a permanent or long lasting physically close association

parasitism

a relationship between two living species in which one organism benefits at the expense of the other.

brood parasites

tricks an animal of a different species into raising its young

parasitoid

insect that is free living as an adult but lays its eggs on another insect, their larvae will eat the insect when they hatch

commensalism

one species benefits while the other is unaffected

antagonistic interactions

one species benefits and the other doesn't. ex: predation and herbivory

mutualism

an interspecific interaction that benefits both species

primary consumer

An organism that eats primary producers

secondary consumer

An organism that eats primary consumers

primary producer

first producer of energy-rich compounds that are later used by other organisms

tertiary consumer

An organism that eats secondary consumers

ecological succession

an array of species shifts gradually as organisms alter their own habitat

primary succession

When a species starts from scratch occurs in habitats that have always had a lack of soil and thus have few or no existing species

pioneer species

colonize new or vacated habiats

secondary success

occurs after a natural or human disturbance removes the natural array of species, but leave the soil in place

keystone species

has a disproportionately large effect on a community relative to its abundance

exotic species

is a species that was introduced to a new habitat and became established there

invasive species

an exotic species whose introduction disrupts the community structure in its new home

detritivores

such as crabs and earthworms eat tiny bits of organic matter

trophic levels

when one organism eat another, energy and nutrients are transferred from the eaten to the eater

food chain

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

food web

when food chains cross connect with one another

primary production

the capture and storage of energy by producers

energy pyramid

graphic representation of the population of the energy captured by producers that reaches higher trophic levels

mutual dependence

when a multiualism interaction cannot survive without the other

biological magnification

predators consumes all the toxic substances their prey consumed, which causes the toxin to become increasingly concentrated as it moves up the food chain

biogeochemical cycle

an essential element moves from one or more environmental reservoirs, through the living components of a ecosystem and then back to the reservoirs

ground water

freshwater reservoir, includes watering the soil and water stored in porous rock layers called aquifers

phosphorus cycle

the biogeochemical cycle that describes the transformation and translocation of ___________ in soil, water, and living and dead organic material.

carbon cycle

nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again.

greenhouse gases

atmospheric gases that keep earth warm by absorbing and reradiating heat

plants use nitrogen from the soil in the form of....

nitrates

nitrogen fixation

some bacteria have a enzyme that breaks apart nitrogen gas and produces ammonia.

ammonia

plants main source of nitrogen

water cycle

moves water from oceans to the atmosphere onto land and into freshwater ecosystems

transpiration

the evaporation of water from the above ground parts of plants, returning most of this water to the atmosphere