Download File

Notes for B 2.3
Classification systems change as
scientists learn more.
Taxonomy changes as scientists make
discoveries.
• Early scientists described 2 kingdoms:
Plants: green and nonmoving
Animals: moving organisms
Three Domains
• Microscopes and other advances in
technology show that there are basically 3
different types of cells.
• Kingdoms are arranged into 3 larger groups
called domains: Bacteria, Archaea, and
Eukarya.
Three Domains
• Bacteria: includes bacteria kingdom
»No nucleus
»Unicellular
»Vary in how they get energy
Archaea
•
•
•
•
•
Kingdom Archaea
No nucleus (prokaryotic)
Unicellular
Vary in how they obtain energy
Distinctive chemistry and live in extreme
environments
Eukarya
• Includes Kingdoms Protista, Fungi, Plantae,
and Animalia
• Eukaryotic (have nuclei)
• Some unicellular, most multicellular
• Vary in the ways they obtain food
• See chart on page B 61.
Six Kingdoms
•
•
•
•
•
•
•
Plantae
Animalia
Protista
Fungi
Archaea
Bacteria
See pages 62 and 63 for an overview of all of
these kingdoms you studied in seventh grade.
The two most familiar kingdoms are
plants and animals.
• Carolus Linneaus divided all the species he
identified into these 2 groups.
• Plantae DNA stored in a nucleus
Can carry out photosynthesis to make
sugars
Contain cell walls around their cell
membrane
Cannot move from place to place
Multicellular
Animalia
• More than 90% of named species are insects.
• Obtain energy by eating organisms or by
eating food made by other organisms
• Can move around for at least part of their lives
• Most have mouths and nervous systems
• Have nuclei (eukaryotic)
• No cell walls
Other organisms make up four more
kingdoms.
• Linnaeus: called mushrooms, molds, and their
relatives plants
• Archaea, Bacteria, and Protista are mostly
microscopic.
• Most organisms on Earth are classified as
bacterial or archaea—prokaryotic, small, and
simple.
Protista
•
•
•
•
•
•
•
•
Most unicellular
Large, complex with a true nucleus
Some eat other organisms.
Some make their own food.
Some resemble fungi.
Most live in water or sea water
Seaweeds
Some scientist think this should be divided into
different kingdoms.
Fungi
•
•
•
•
•
•
Yeasts
Molds
Downy Mildew
Most have cell walls
Remain rooted in one place
Many act as decomposers
Archaea
• Resemble bacteria in size and shape
• Genetic differences
• Appear to be related to eukaryotes, but do not
have nuclei
• Cell structure differs from bacteria
• Live in many environs, especially the oceans
• Some live in extreme environs such as geysers,
hot springs, hot vents, salty ponds etc.
Bacteria
•
•
•
•
•
Live nearly everywhere on Earth
Helpful/harmful
Unicellular
Prokaryotes (no nucleus)
Most have cell walls, but not the kind plants
have
• Reproduce quickly by binary fission
Species and environments change.
• Over a million species named
• Estimated millions—maybe tens of millions–
not yet discovered
• Species evolve over time as individual
organisms and environments change.
• Changes may result in pressures that affect
living space, availability of food or other
resources, or from other organisms.
•Review Questions for B
2.3
• Page 67B
Number 1
•
•
•
•
•
•
Plantae
Animalia
Protista
Fungi
Bacteria
Archaea
Number 2
• Organisms are sorted according to
general traits.
Number 3
• See pages 62-63.
Number 4
• Plants use the sun’s energy and air to make
sugars.
• Fungi take in nutrients from their
surroundings.
Number 5
• No—does not have a nucleus
• Yes—the membrane and DNA are like a
nucleus
Quiz B 2.3
• Fill ins:
Animalia
species
Bacteria
Domains
(6 terms used)
Archaea
Protista
Fungi
Plantae
What are the 3 domains? List 2 traits
that are used to classify organisms
into each domain.