-
living things
all organisms descend from a single-celled ancestor
-
viruses
dont carry out physiological fuctions on their own yet and contain genetic material that evolves. prob evolved from cellular organisms
-
unicellular organism
single cell carries out all the functions of life
-
multicellular
made of many cells that are specialized cells that fulfill different functions
-
discovered the microscope in the 1590's
zaccharias and hans janssen
-
hooke and leeuwenhoek
improved and aplied the microscope to living organisms
-
coined the term cells to describe the repeated structures he saw in cork tissue
Hooke
-
cell theory
- cells are the basic structural and physiological units of all living organisms
- cells are both distinct entities and building blocks of more complex organisms
-
modern cell theory
- all cells come from preexisting cells
- all cells are similar in chemical composition
- most of the chemical reactions in life occur within cells
- complete sets of genetic info r replicated and passed on during cell division
-
charles darwinn
- natural selection
- proposed that living things are descended
- from common ancestors and therefore related to one
- another
-
species
- a group of organisms that look
- alike and can breed successfully with
- one another
-
the diversity of life is due to evolution by
natural selection
-
natural selection
- Traits that increase the
- probability that the organism
- will survive and reproduce
- will become more common in
- the population.
-
natural selection leads to
adaption
-
dna
- the information that is passed from
- parent to daughter cells
-
genome
- sum total of all the DNA in the
- cell
-
All cells in a multicellular organism have
the same
genome
-
repeating
subunits—nucleotides
dna
-
gene
- a specific segment
- of DNA molecule—
- contains information for
- making proteins
-
The human genome is
composed of about 3
billion nucleotides
-
mutations
- Alterations of the genome are called mutations,
- which can lead to the production of altered
- proteins.
- Mutations can occur spontaneously or be induced
- by environmental factors such as chemicals and
- radiation.
- Most mutations are deleterious but occasionally
- they prove beneficial.
- Mutations are the raw material of evolution.
-
cells acquire _____ from the environment
nutrients
-
nutrients
- -supply energy and materials for
- building biological structures (synthesis).
- -molecules contain energy in the
- chemical bonds.
-
Life depends on the thousands of _____ that occur within cells, all of which
require materials to be moved into and out of
cells in a controlled manner.
chemical reactions
-
cells are specialized and organized into
tissues
-
tissues are organized into
organs
-
individuals are a part of
population
-
Interacting populations of many different
species form a
community
-
Interacting communities in a given area
form
ecosystems
-
Study of one type of organism can usually be generalized to
other organisms (because all share a common ancestor, genetic
code, and similar cellular structures).
-
•Bacteria taught us our basic understanding of chemical reactions in cells.
•The biochemistry of photosynthesis came from experiments on a pond alga, Chlorella.
•Much knowledge of plant genetics has come from studies on Arabidopsis.
•Knowledge about the genetics of animal development has come from sea urchins,
roundworms, frogs, fish, chickens, and fruit flies.
model systems
-
all species on earth share a common
ancestor
-
Modern molecular methods allow
biologists to compare genomes.
- The greater the distance between
- genomes, the more distant the common
- ancestor.
-
Earth is about 5 billion years old
Life arose by chemical evolution.
Chemical evolution led to the appearance of life about
4 billion years ago
Random inorganic chemical interactions eventually
produced more complex molecules.
Molecules that could reproduce themselves were
critical.
-
Control over entrance, retention, and exit of molecules was possible because of
compartmentalization by
membranes
-
Around 3.8 billion years ago certain molecules became enclosed in fatty
compartments or
vesicles
-
cells were tiny packages of molecules that lived separately from one another and had
no internal membrane-enclosed compartments.
prokaryotic cells
-
consequences of photosynthesis
- • O2 accumulated in the atmosphere
- • Aerobic metabolism began
- • Ozone layer formed—allowed
- organisms to live on land
-
evolved from prokaryotes
Eukaryotic cells
-
organelles
- membrane bound
- compartments with specialized functions:
- • Nucleus
- • Chloroplast
-
Cellular specialization
- Cells became
- specialized to perform certain functions.
-
all orgnisms on earth today descended from an original unicellular organism that lived around 4 billion yrs ago
-
species two names
- genus name- share common ancestor (homo)
- species name- identifies within the genus (sapiens)
-
3 domains of life
- • Bacteria
- • Archaea
- • Eukarya
-
Multicellular Eukarya (plants, animals,
and fungi)
- evolved from protists—
- unicellular microbial eukaryotes.
-
autotrophs
- organisms capable of
- photosynthesis
-
heterotrophs
- require a source of
- molecules synthesized by other
- organisms
-
independent variable
- the variable being
- manipulated
-
dependent variable
- the response that is
- measured
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