Cell theory
all living things are made of cells
Eukaryotic cells
has a distint nucleus. most organisms have these cells.
Prokaryotic cells
no nucleus.
ex) bacteria cells
set of individuals that can mate and produce fertile offspring.
Estimate 4 million and 100 million. But only identified 2 million. Insects make up most of worlds species.
Study of how organisms interact with their living environment. Study of connections and nature.
What are the levels of organization of matter?
Atom, molecule, cell, organism, population, community, ecosystem, biosphere.
group of same species living in a particular place
populations of different species living in a particular place.
genetic diversity
variation in population
place where population or individuals live
community of different species interacting with one another and with the non-living environment.
puddle of water-ocean. Could be natural or artificial (reservoir)
consists of the parts of the Earth’s air, water, soil. Where life is found
Four components
atmosphere=air, hydrosphere=water, geosphere=rock, soil, biosphere= life
temperature and precipitation animal and plant life
Large regions such as rain forests, deserts, and etc with Distinct climates and species
Life on earth depends on 3 interconnected factors such as
1) one way flow of high quality energy which is the sun
2) cycling of matter or nutrients=earth is closed so everything has to be recycles. fixed supply of nutrients have to be recycles to support life
3) gravity allows planet to hold on to its atmosphere and keeps the movement and cycling of chemicals through the air, water, soil, and organisms
Biotic factors
living and once living things
nonliving components such as air, water, heat, energy
Limiting factor principle
too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance
producers= autotrophs
Photosynthesis= grass
primary= plant eaters
secondary= carnivores such as birds, frogs; eats primary
third higher level= tigers, wolves; eats secondary
Bacteria, fungi
release nutrients of dead bodies
Eats plants and animals
CO2+water+solar energy=glucose+ oxygen
feed on the waste or dead bodies of other organisms
oxygen is used
anaerobic respiration
fermentation= breakdown glucose without oxygen
Ecological efficiency
the % of usable chemical energy transferred as biomass from one trophic level to the next, 2%-40% but average is 10%
3 types of natural selection
Stabilizing, directional, disruptive
stabilizing NS
favors average individual in a population
occurs when natural selection favors one of the extreme variations of a trait
individuals with either extreme of a trait variations are selected for.
ending up with 2 extremes
can lead to 2 different species