all organisms descend from a single-celled ancestor
dont carry out physiological fuctions on their own yet and contain genetic material that evolves. prob evolved from cellular organisms
single cell carries out all the functions of life
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
- 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
- natural selection
- proposed that living things are descended
- from common ancestors and therefore related to one
- a group of organisms that look
- alike and can breed successfully with
- one another
the diversity of life is due to evolution by
- Traits that increase the
- probability that the organism
- will survive and reproduce
- will become more common in
- the population.
natural selection leads to
- the information that is passed from
- parent to daughter cells
- sum total of all the DNA in the
All cells in a multicellular organism have
- a specific segment
- of DNA molecule—
- contains information for
- making proteins
The human genome is
composed of about 3
- Alterations of the genome are called mutations,
- which can lead to the production of altered
- Mutations can occur spontaneously or be induced
- by environmental factors such as chemicals and
- Most mutations are deleterious but occasionally
- they prove beneficial.
- Mutations are the raw material of evolution.
cells acquire _____ from the environment
- -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.
cells are specialized and organized into
tissues are organized into
individuals are a part of
Interacting populations of many different
species form a
Interacting communities in a given area
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.
all species on earth share a common
Modern molecular methods allow
biologists to compare genomes.
- The greater the distance between
- genomes, the more distant the common
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
Control over entrance, retention, and exit of molecules was possible because of
Around 3.8 billion years ago certain molecules became enclosed in fatty
cells were tiny packages of molecules that lived separately from one another and had
no internal membrane-enclosed compartments.
consequences of photosynthesis
- • O2 accumulated in the atmosphere
- • Aerobic metabolism began
- • Ozone layer formed—allowed
- organisms to live on land
evolved from prokaryotes
- membrane bound
- compartments with specialized functions:
- • Nucleus
- • Chloroplast
- 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,
- evolved from protists—
- unicellular microbial eukaryotes.
- organisms capable of
- require a source of
- molecules synthesized by other
- the variable being
- the response that is