Bio Exam 2

Population

group of organisms of the same species living in the same area at the same time

Fundamental niche

the full range of conditions where a species can live and survive

Realized niche

the actual range where a species does live because of competition and other limits

Community

all populations of different species living in one area

Ecosystem

all living (biotic) and nonliving (abiotic) factors interacting in an area

Biosphere

all ecosystems on earth combined

Gene pool

all alleles in a population

Allele

different versions of a gene

Fitness

ability of an organism to survive and reproduce

Natural selection

organisms with beneficial traits survive and reproduce more

Artificial selection

humans select traits for breeding

Genetic drift

random changes in allele frequencies

Founder effect

small group starts a new population with reduced genetic variation

Hardy-Weinberg (genetic equilibrium)

no change in allele frequencies in a population over time

Adaptive radiation

one ancestor evolves into many species in different environments

Reproductive isolation

when populations can no longer interbreed

Ecology

study of interactions between organisms and their environment

Biome

large region defined by climate and typical organisms

Biotic factors

living components of an ecosystem

Abiotic factors

nonliving components (temp, water, and sunlight)

Climate

long term weather patterns

Weather

short term atmospheric conditions

Autotroph

organisms that make its own food (producer)

Heterotroph

organism that eats other organisms

Decomposer

breaks down dead organisms and recycles nutrients

Food chain

pathway to energy transfer between organisms

Energy pyramid

shows energy loss at each trophic level

Reservoir (cycles)

place where matter is stored in earth systems

Exponential growth (J curve)

rapid population growth with unlimited resources

Logistic growth (S curve)

growth slows and levels at carrying capacity

Carrying capacity

maximum population at environment can support

Density dependent limiting factors

stronger effect as population increases (disease or competition)

Density independent limiting factor

affects all populations regardless of size (storms or fire)

Secondary succesion

ecosystem regrowth after disturbance where soil remains

Climax community

stable final stage of ecological succession

Biodiversity

variety of species in an ecosystem that increases stability

Pathogen

organism that causes disease

Germ theory

disease is caused by microorganisms

Vector

organism that carries disease without getting sick

Zoonosis

disease transmitted from animals to humans

Antigen

foreign substance that triggers immune response

Antibody

protein that blinds and helps destroy pathogens

Inflammation

immune response causing swelling, redness, and pain

Interferons

proteins that block virus replication

Vaccine

triggers immunity using a weakened pathogen

Fever

slows pathogen growth by raising body temperature

First line of defense

skin, mucus, and physical barriers

Second line of defense

inflammation and fever

Skeletal muscle

voluntary muscle attached to bones

Smooth muscle

involuntary muscle in organs

Cardiac muscle

muscle found only in the heart

Concentric contraction

muscle shortens

Eccentric contraction

muscle lengthens under tension

Isometric contraction

muscle contracts without changing length

Tendon

connects muscle to bone

Ligament

connects bone to bone

Origin

stationary muscle attachment point

Insertion

movable muscle attachment point

Axial skeleton

skull, spine, rib cage

Appendicular skeleton

arms and legs

Hinge joints

movement in one direction (knee and elbow)

Ball and socket joint

full rotation (shoulder and hip)

Pivot joint

rotation movement

gliding joint

bones slide over each other

Arteries

carry blood away from the heart

Veins

carry blood toward the heart

Capillaries

site of gas and nutrients exchange

Red blood cells

carry oxygen

White blood cells

fight infection

Platelets

help blood clot

Plasma

liquid part of blood carrying nutrients and waste

Atrium

heart chamber that receives blood

Ventricle

heart chamber that pumps blood out

Trachea

windpipe that carries air to lungs

Bronchi

main branches into lungs

Bronchioles

smaller airway in lungs

Alveoli

air sacs where gas exchange occurs

Larynx

voice box

Pharynx

throat region

Cilia

hair like structures that filter air

Esophagus

tube that carries food to stomach

Stomach

breaks down food with acids and enzymes

Small intestine

main site of nutrient absorption

Large intestine

absorbs water and forms waste

Liver

produces bile and detoxifies blood

Pancreas

produces digestive enzymes

Gallbladder

stores bile

Phenotype

physical genetic makeup of species

Genotype

underlying genetic makeup

Stabilizing selection

intermediate phenotype shows best fitness

Directional selection

one extreme phenotype is better suited for environment and that phenotype takes over

Disruptive selection

intermediate is the least fit

Geographic isolation

two populations become separated by a geographical barrier (river, road, or ocean)

Behavioral isolation

two populations have different mating behaviors so organisms have no desire to mate

Temporal isolation

two populations dont mate with the same timing

Mechanical isolation

reproductive organs become so different they can no longer mate

Tundra

ground frozen and treeless

Tiaga

largest biome, animals hibernate, cold

Temperate grasslands

rolling terrain, large, dry

Deciduous forest

4 distinct seasons and camouflage