BIOLOGY: LIFE ON EARTH
CH 1 Introduction to life on earth
1.1 what is life?
Biology: Study of life
Characteristics of life:
Maintain organized complexity
Acquire & use materials & energy
o Plants: sun (autotrophic: “self-feeding” - make food)
o People/animals: eat & drink (heterotrophic: “other feeding” - hunt/get food)
o Energy is used to complete processes (digestive system, body temperature, brain
work)
Grow
o Need energy to grow, increase in size internally & externally (gym: increase in
blood flow grow)
Reproduce
o Asexual: 1 organism
o Sexual: 2 organisms
Evolve
o Genetic change in population
natural occurrences:
Difference amongst members
Offspring inherit differences
Ones inherited: better chance of survival
Respond to stimuli
o Receive stimuli to respond: gravity, sound, light
Plants: leave hang if need water
Humans: Low blood sugar, brain respond: sweat
Bacteria: move towards favorable conditions
Viruses: multiply, mutate (adapt), inert (cannot move/unreactive) & simple
What is life?
Organisms acquire and use materials and energy. Materials are obtained from other organisms
or the nonliving environment and are repeatedly recycled. Energy must be continuously
, captured from sunlight by photosynthetic organisms, whose bodies supply energy to all other
organisms. Organisms also show characteristics of life.
Natural selection: “Process by which organisms with certain inherited traits survive and
reproduce better than others in a given environment”
Organisms inherit certain traits, which benefit them & help reproduce & survive. This trait
becomes more common in population. (Short teeth beavers mutate: long teeth more
successful. Short teeth die out)
Evolution: “Change in DNA occurring in a population over time”
Example: Humans & technology: swiping: different shaped thumbs, extra vertebrae neck
Example: If living in smoke: to adapt: 3rd lung, extra filter lung, long nose hairs
(mutations)
Note: Genetic change is incredibly slow
Natural occurrences:
Difference amongst members
Offspring inherit differences
Ones inherited: better chance of survival
What is evolution?
Evolution is the scientific theory that modern organisms descended, with changes, from
earlier organisms. Evolutions occurs as a consequence of genetic differences, originally arising
as mutations, among members of a population, inheritance of these differences by offspring
and natural selection of the differences produced by the best adaptations to the organism’s
environment.
CH 1 Introduction to life on earth
1.1 what is life?
Biology: Study of life
Characteristics of life:
Maintain organized complexity
Acquire & use materials & energy
o Plants: sun (autotrophic: “self-feeding” - make food)
o People/animals: eat & drink (heterotrophic: “other feeding” - hunt/get food)
o Energy is used to complete processes (digestive system, body temperature, brain
work)
Grow
o Need energy to grow, increase in size internally & externally (gym: increase in
blood flow grow)
Reproduce
o Asexual: 1 organism
o Sexual: 2 organisms
Evolve
o Genetic change in population
natural occurrences:
Difference amongst members
Offspring inherit differences
Ones inherited: better chance of survival
Respond to stimuli
o Receive stimuli to respond: gravity, sound, light
Plants: leave hang if need water
Humans: Low blood sugar, brain respond: sweat
Bacteria: move towards favorable conditions
Viruses: multiply, mutate (adapt), inert (cannot move/unreactive) & simple
What is life?
Organisms acquire and use materials and energy. Materials are obtained from other organisms
or the nonliving environment and are repeatedly recycled. Energy must be continuously
, captured from sunlight by photosynthetic organisms, whose bodies supply energy to all other
organisms. Organisms also show characteristics of life.
Natural selection: “Process by which organisms with certain inherited traits survive and
reproduce better than others in a given environment”
Organisms inherit certain traits, which benefit them & help reproduce & survive. This trait
becomes more common in population. (Short teeth beavers mutate: long teeth more
successful. Short teeth die out)
Evolution: “Change in DNA occurring in a population over time”
Example: Humans & technology: swiping: different shaped thumbs, extra vertebrae neck
Example: If living in smoke: to adapt: 3rd lung, extra filter lung, long nose hairs
(mutations)
Note: Genetic change is incredibly slow
Natural occurrences:
Difference amongst members
Offspring inherit differences
Ones inherited: better chance of survival
What is evolution?
Evolution is the scientific theory that modern organisms descended, with changes, from
earlier organisms. Evolutions occurs as a consequence of genetic differences, originally arising
as mutations, among members of a population, inheritance of these differences by offspring
and natural selection of the differences produced by the best adaptations to the organism’s
environment.
