ENSC Exit Exam

Biological Organization

atom, molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere

Cell

smallest fundamental unit of structure and function in living organisms

organelles

which provide specific functions for the cell

organism

are individual living entities. For example, each tree in a forest

population

A ll the individuals of a species living within a specific area are collectively called a

community

is the sum of populations inhabiting a particular area

ecosystem

consists of all the living things in a particular area together with the abiotic, nonliving parts of that environment such as nitrogen in the soil or rain water

biosphere

is the collection of all ecosystems, and it represents the zones of life on earth. It includes land, water, and even the atmosphere to a certain extent.

The Ocean contains what % of all the water on earth?

75%

freshwater ecosystems are

1.8% of the Earth's surface

Biomes

a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.

food webs

A complex diagram representing the many energy pathways in an ecosystem

When did humans first appear?

200,000 years ago

Steps of the Scientific Method

observation, question, hypothesis, prediction, experiment, conclusion

important parts of a hypothesis

must be falsifiable

independent variable

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

dependent variable

The measurable effect, outcome, or response in which the research is interested.

Sustainability

meeting the needs of the present without compromising the ability of future generations to meet their own needs

triple bottom-line

recognition of the need for organizations to improve the state of people, the planet, and profit simultaneously if they are to achieve sustainable, long-term growth

IPAT

Impact = Population x Affluence x Technology

precautionary principle

When a threat is of serious environmental damage, we should not wait for scientific proof before taking action.

utilitarian justification

for environmental conservation means that we should protect the environment because doing so provides a direct economic benefit to people

ecological justification

for environmental conservation means that we should protect the environmental because doing so will protect both species that are beneficial to other as well as other species and an ecological justification for conservation acknowledges the many ecosystem services that we derive from healthy ecosystems.

aesthetic justification

for conservation acknowledges that many people enjoy the outdoors and do not want to live in a world without wilderness

moral justification

represents the belief that various aspects of the environment have a right to exist and that it is our moral obligation to allow them to continue or help them persist

Population

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

population ecology

therefore, is the study of how individuals of a particular species interact with their environment and change over time.

population density

Number of individuals per unit area

Dispersion

the pattern of spacing among individuals within the boundaries of the population

age structure

number of males and females of each age in a population

exponential growth

meaning that the population is increasing by a fixed percentage each year

characterized by a J shaped curve

exponential growth model

G = r x N

per capita rate of increase

r = (birth rate + immigration rate) - (death rate + emigration rate)

If r is positive (> zero)

the population is increasing in size; this means that the birth and immigration rates are greater than death and emigration.

If r is negative (< zero)

the population is decreasing in size; this means that the birth and immigration rates are less than death and emigration rates.

when do populations exhibit logistic growth

When resources are limited

carrying capacity

(K) The largest number of individuals in a population that an environment can support

logistic growth model

G = r x N x (1 - N/K)

density-dependent factors

A limiting factor of a population wherein large, dense populations are more strongly affected than small, less crowded ones.

examples of density-dependent factors

competition, predation, parasitism, disease

density-independent factors

limiting factor that affects all populations in similar ways, regardless of population size

examples of density-independent factors

Temperature, Weather, Natural Disasters, Human Activity

survivorship

the percentage of members of a group that are likely to survive to any given age

Life tables

age-specific summaries of the survival pattern of a population

survivorship curves

Graph of the proportion of a cohort still alive at each age.

Type I survivorship

have the highest probability of surviving every age interval until old age, then the risk of dying increases dramatically. Humans are an example of a species with a Type I survivorship curve

Type II survivorship

is intermediate between the others and suggests that such species have an even chance of dying at any age. Many birds, small mammals such as squirrels, and small reptiles, like lizards, have a Type II survivorship curve

Type III survivorship

most of the deaths occur in the youngest age groups. Juvenile survivorship is very low and many individuals die young but individuals lucky enough to survive the first few age intervals are likely to live a much longer time

Demography

The scientific study of population characteristics.

age structure diagram

graph of the numbers of males and females within different age groups of a population

In Stage 1

birth rates are high, but death rates are high as well. Therefore, the population growth rate is low or close to zero

stage 2

the birth rate is higher than the death rate, so population growth rate is high. This means that population size increases greatly during Stage 2 of the demographic transition model

Stage 3

lower birth and death rates, high growth rate. birth rates still higher

stage 4

With low birth rates and low death rates, population growth rate is approximately zero in

Fertility

actual level of reproduction of a population per individual, based on the number of live births that occur

Preindustrial stage

stage 1: birth and death rates high, population grows slowly, infant mortality high

industrializing/urbanizing stage

stage 2: death rates lower, high birth rate, high growth rate

the mature/industrial stage

stage 3: drop in birth rates, drop in death rates

birth rates > death = increasing population

postindustrial stage.

stage 4: low birth and death rates, population growth = 0

crude birth rate

The total number of live births in a year for every 1,000 people alive in the society.

total fertility rate

The average number of children born to a woman during her childbearing years.

replacement fertility rate

2.1

caprocks

rock formations that are dense enough to prevent oil and natural gas from seeping to the surface

primary energy

energy contained in natural resources (coal, oil, sunlight, wind, uranium)

secondary energy

when primary energy is converted into another form (electricity)

coal produces emissions such as

sulfur dioxide (SO2) and nitrogen oxides (NOx) that are associated with acid rain (more on this in Chapter 5). Carbon dioxide (CO2)

gases in the atmosphere

Nitrogen - 78 percent.

Oxygen - 21 percent.

Argon - 0.93 percent.

Carbon dioxide - 0.038 percent.

what layer of the atmosphere has weather

Troposphere

6 air pollutants

carbon monoxide, sulfer dioxide, nitrogen dioxide, tropospheric ozone, PM, lead

Greenhouse Gases (GHGs)

carbon dioxide, water vapor, methane, and CFCs and HCFCs

gases in the atmosphere that trap/reflect low-energy heat

Highest global warming potential

CFCs, N2O, CH4, CO2, H2O

hydrogen bond and water

when the positive (H) end of one molecule is attracted to the negative (O) end of another. Allows water to dissolve a wide variety of substances

universal solvent

Water- due to its polarity and ability to dissolve many different solutes

cohesion

Attraction between molecules of the same substance

adhesion

An attraction between molecules of different substances

capillary action

the combined force of attraction among water molecules and with the molecules of surrounding materials

Porosity

The percentage of the total volume of a rock or sediment that consists of open spaces.

permeability

The ability of a rock or sediment to let fluids pass through its open spaces, or pores.