Biology Reference Sheet (Page 5 of 8) in pdf

SYMBIOTIC RELATIONSHIPS:

Symbiosis – permanent, close association between one or more organisms of different species

Mutualism – a symbiotic relationship in which both species benefit (ex: in subtropical regions, ants protect acacia trees by fighting invaders, acacia tree provides nectar to ants)

Commensalism – symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited (ex: Spanish moss grows on and hangs from limbs of

trees, but does not obtain any nutrients from tree, nor harm the tree)

Parasitism – symbiotic relationship in which one organism benefits at the expense of another, usually another species (ex: parasites such as bacteria, roundworms, tapeworms live

in the intestines of organisms to obtain nutrients and reproduce, but cause disease in the organisms)

FOOD CHAIN:

SOME EXAMPLES OF

Path of energy from producer to consumer

ENVIRONMENTAL LIMITING FACTORS

Each level is called a trophic level (trophic = energy)

Biotic (living)

Abiotic (nonliving)

Approximately 10% energy is transferred to next level

Plants

Climate

90% used for personal metabolism and development

Animals

Light

FOOD WEB:

Bacteria

Soil

Interconnected food chains

Prey

Water

Shows all possible feeding relationships at each trophic level in a community

Food Sources

Shelter

ECOLOGICAL PYRAMID:

(Nutrients)

Pollution

Representation of energy transfer

Pyramid of Energy – each level represents energy available at that level, 90% decline

Pyramid of Biomass – each level represents amount level above needs to consume

Pyramid of Numbers – each level represents number of organisms consumed by level above it

SPECIES / POPULATION SURVIVAL:

- Natural Selection – mechanism for change in populations; occurs when organisms with favorable variations survive, reproduce, and pass their

variations to the next generation; “survival of the fittest”

- Adaptation (Behavioral or Physiological) – evolution of a structure, behavior, or internal process that enables an organism to respond to

environmental factors and lives to produce offspring

- Limiting Factors (Environmental) – any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms

- Genetic Mutations – any change or random error in a DNA sequence (one gene or many; somatic cells or gametes)

- Biodiversity – variety of life in an area; usually measured as the number of species that live in an area

- Evolution (Macroevolution vs. Microevolution) – gradual change in a species through adaptations over time

- Endangered Species – number of individuals in the species falls so low that extinction is possible

- Extinction – disappearance of a species when the last of its members die

- Carrying Capacity - number of individuals that the resources of an environment can normally and persistently support.

CHARACTERISTICS OF LIVING THINGS:

EXPLANATIONS OF THE ORIGIN OF LIFE ON EARTH

require food for energy to carry out life processes

Most modern organisms could not have survive the harsh conditions of Earth’s early atmosphere. It is

use energy to maintain homeostasis

still uncertain where the first living things came from.

respond to stimuli in the environment

Several scientists contributed to the explanations: Miller -Urey, Oparin (atmospheric origin of organic

compounds), Pasteur (disproved spontaneous generation of microbes)

grow and develop

Endosymbiotic Theory - states that free-living bacteria were engulfed by other prokaryotes. Explains

reproduce similar offspring

how mitochondria , chloroplasts and other organelles formed

pass genetic information to their offspring

composed of cells

ALTERNATION OF GENERATIONS:

composed of organic based compounds

- type of life cycle found in some algae, fungi, and all plants where an organism alternates between a

haploid (n) gametophyte generation and a diploid (2n) sporophyte generation

CYCLES:

(Matter cannot be created nor destroyed, but can be converted/recycled to other forms)

Water Cycle – water is recycled through evaporation, condensation, precipitation, runoff, groundwater, aquifers, respiration, transpiration, excretion,

decomposition

Nitrogen Cycle – producers take in nitrogen compounds in soil and pass to consumers that consume the producers; decomposers (bacteria) break down

nitrogen compounds and release nitrogen gas to air or usable nitrogen so the soil

Carbon Cycle – carbon is recycled through respiration, photosynthesis, fuel combustion, decomposition; carbon can be atmospheric or dissolved, or can be

found in organic compounds within the body

FACTORS THAT AFFECT CLIMATE CHANGE:

FACTORS THAT AFFECT RESOURCE USE AND SUSTAINABILITY:

- distance from the sea

- population count

- recycling programs

- ocean currents

- number of producers and consumers

- conservation programs

- Direction of prevailing winds

- percapita consumption

- substitution programs