Transcript Classification and Taxonomy - Lamar County School District

Classification and
Taxonomy
Biology 1
11.1 Taxonomy
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Branch of biology that classifies organisms
into a series of groups called taxa. The most
common system used today has 7 taxa:
kingdom, phylum, class, order, family, genus
and species.
The largest taxa is kingdom, it has the most
numbers of organisms. The smallest is species
which has the fewest in it.
Taxonomy of Life
All Living Things
Monera
Archaebacteria
Eubacteria
Protista
Fungi
Plantae
Animalia
Taxonomy …
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Organisms are named using their genus as
their first name and the species as the last
name. Genus is always capitalized, species is
NEVER capitalized, both are italicized.
Giving organisms two names is known as
binomial nomenclature.
Sometimes three names are used when a
subspecies is known. Then it is trinomial
nomenclature.
More Taxonomy….
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Plant taxonomists use
the term “division”
instead of phylum.
By using DNA samples,
relationships between
organisms can be
determined with great
accuracy.
Bacillus subtilis
Abutilon theophrasti
Micrurus fulvius
11.2 Dicotomous Key
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Organisms are placed into their correct orders
by using a dicotomous key which is a series of
questions.
http://pals.sri.com/tasks/58/DichotomousKey/directs.html
Viruses
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Characteristics of viruses
NON-living organisms
 Smaller than the smallest
prokaryotic cells.
 Do not have the characteristics of
living things.
 Can only reproduce if they get
inside a host organism.
If they infect a bacterium cell, they
are called bacteriophages.
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Viral Structure
Structure:
•Inner core composed of nucleic acid,
DNA or RNA, surrounded by a
capsid.
Lytic cycle is the
method by which
viruses reproduce
themselves.
In order to infect a
plant or animal cell,
the capsid must
match a receptor site
on the host cell.
Specific Viruses
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The virus that causes AIDS can only attach to
white blood cells.
Antibiotics are not effective against viruses.
Antibiotic means “against life” and they only
work against bacterial infections because
bacteria are living organisms.
Viruses are NOT living!!!!!
Antibiotics are sometimes effective against
fungal infections.
11.3 Kingdom Monera
Monera
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The only kingdom to
include prokaryotes is
the kingdom monera.
Prokaryotes vs Eukaryotes
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Prokaryotes
Do NOT have a true nucleus
 Do NOT have membrane-bound organelles
 DO have a cell wall outside the cell membrane
Monerans are the most widespread and most
numerous organisms on earth
Sometimes divided into 2 kingdoms: archaebacteria
and eubacteria.
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Archaebacteria
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Believed to be the oldest living organisms
Can live in harsh environments such as hot
sulfur springs, volcanic deep-sea vents on the
ocean floor, the Great Salt Lake, and even the
intestines of mammals.
Some are autotrophic (can make their own
food)
Eubacteria
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More common type of bacteria
Classified according to shape and how they
respond to a process called Gram staining
Some are heterotrophs and rely on others as
their food source
Others are parasites and get their nutrients by
feeding on other organisms
Some are saprotrophs and feed on dead
organisms organic wastes
More Eubacteria feeding habits
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Still others are autotrophs and make their own
food.
Example: cynobacteria are photosynthetic
autotrophs
Chemosynthetic autotrophs make food by the
break down of inorganic compounds that
contain nitrogen and sulfur
Bacteria get a bad rap, but…
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Actually there are more PROS than CONS
PROS:
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Nitrogen-fixing bacteria live in the roots of plants
Many foods such as pickles, yogurt, sauerkraut, and Swiss
cheese owe their distinctive odors and flavors to bacteria.
Certain ones make antibiotics such as neomycin and
erythromycin
Probiotics live in the intestines and produce vitamins,
enhance the absorption of nutrients and strengthen the
immune system.
On the other hand…
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Many do cause diseases
Some form endospores which can cause
botulism or tetanus
Others cause Lyme disease, strep throat, and
cavities in your teeth
11.5 Kingdom Protista
Protists
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Contains so many organisms that don’t fit
elsewhere.
No such thing as a typical protist
Microscopic or large, unicellular or multicellular
Autotrophs or heterotrophs
Are all alike in that they are EUKARYOTES!
Protozoans – animal-like protists
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Single-celled
One that has no definite shape is the amoeba
Moves by pseudopods which are extensions of its
cytoplasm
Others move using cilia or flagella
A paramecium moves using cilia
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Some cause diseases such as malaria
Some have specialized parts such as the
contractile vacuole which pump water our of
the cell. If this did not take place, the cell
would burst due to osmosis.
Plant-like protists
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Many of these are autotrophs and contain
chlorophyll and carry out photosynthesis.
These protists are algae.
Algae do not have roots, stems, leaves, or
flowers like plants
Because they have other pigments than
chlorophyll, they may appear red, brown, or
golden
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Algae are important food source for many
animals
Types of algae include euglenoids, golden
algae, green algae, brown algae, and red algae.
Diatoms have a glass-like outer shell. It forms
diatomaceous earth when it dies. This is used
as an abrasive in toothpastes and as a filtering
agent for liquids
Fungal-like protists
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Decompose dead organisms
Includes slime molds, downy mildews, and
water molds
11.6 Kingdom Fungi
Kingdom Fungi
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Found everywhere there is moisture.
Most are multi-celled, but a few are single-celled like
yeasts.
The roles of fungi include that of consumer because
they do not contain chlorophyll and therefore cannot
make their own food.
Fungi feed by a process called extracellular digestion.
They send out hyphae into their source of food. The
hyphae secret enzymes that break down the food into
small enough particles that can be absorbed into the
fungi by diffusion.
Fungal Facts
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Have cell walls made of chitin.
Some are saprophytes which feed on dead organic
matter.
They are decomposers
Some are parasites and cause ringworm and athlete’s
foot in humans.
Lichens which are found growing on rocks and trees
are actually two organisms, a fungus and a green
algae which live in a mutualistic relationship.
Reproduction and locomotion
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Some fungi reproduce sexually, some
asexually, and some both sexually AND
asexually.
Yeasts reproduce by budding.
Most mushrooms reproduce sexually by
forming spores called basidiospores.
Bread molds produce asexual spores in
specialized hypha called a sporangium.
The “Good-guy” Fungi
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Can be harmful or beneficial
Benefits:
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Some are edible (mushrooms)
Yeasts make bread rise, juice ferment to alcohol
Penicillium mold is used to make penicillin
Others make cheeses
“Bad-Guy Fungi”
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Cause plant diseases such as rusts and smuts
Destroys large amounts of crops and timber
each year
Some fungal spores are fatal if ingested by
humans.
Kingdom Plantae
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Characteristics of Plants:
Made of more than one cell
 Cells are eukaryotic
 Autotrophic – can make their own food by
photosynthesis
Also have cell walls made of cellulose
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250 000 species exist today!
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Botanist –scientist who studies plants
Two major divisions:
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Non-vascular plants
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Vascular plants
12.2 Non-vascular plants
(bryophytes)
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3 divisions:
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Bryophyta - mosses
Hepatophyta - liverworts
Antheocerophyta - hornworts
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Scan diagram of moss pg 201
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Hepatophyta: less than 2 cm tall
Antheocerophyta: hornworts –
None of these have true leaves, nor roots.
Have rhizoids that anchor them like roots
The only way they receive water or nutrients is
by osmosis or diffusion.
Reproduction
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Reproduce by using spores that contain either
the egg or the sperm cell
Bryophytes undergo alternation of generations
which is in two stages:
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First: gametophyte stage – haploid cells
2nd: sporophyte stage – diploid cells undergo
meiosis to produce spores.
12.3 Vascular Plants
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Tissues that can transport materials throughout
the plant.
Two kinds of vascular tissue:
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Xylem: carries water and minerals UP to the stem
and leaves.
Phloem: carries food from the leaves to wherever
it is needed
Divided into 2 divisions according to method of
reproduction.
Seedless vascular plants
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Seedless vascular plants form spores and are
found in warm, moist regions.
Pterophyta: ferns – 10,000 species
Produce spores in brown cases called sporangia
found on the leaves or fronds
 Have thick underground stems called rhizomes
Psilotopohyta: whisk ferns – no roots and no true
leaves
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Lycophyta: club mosses – have true roots,
stems, and leaves
Sphenophyta: horsetails – only one genus still
alive today
Seed producing - Gymnosperms
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Produce seeds either in cones or in some
“naked” form.
Seed is not protected by a fruit
Cycadophyta: cycads
Ginkophyta: only one living species – Gingko
liloba – bright yellow leaves
Gnetophyta: woody vines, small shrubs, or
turnip-like plants
Coniferophyta: conifers
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Produce seeds in cones – needlike leaves
Very important – provide building materials,
paper, medicine
Tallest trees are in this division – the redwoods
Seed Producers - Angiosperms
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Flowering plants – anthophyta
All have flowers, but some flowers are so
small they are not noticeable.
240,000 species
All have roots, stems, and leaves
Seed produced in the flower and protected by a
fruit
Two groups: Monocots & Dicots
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Monocotyledons:
Have one seed leaf
Parallel veins
Flower parts in groups of three
Examples: corn, lilies, pineapple, and grasses
Dicotyledons
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Have 2 seed leaves
Veins branched or netted
Flower parts in 4’s or 5’s
170 000 species
Examples: roses, daisies, dogwoods, maple
trees, shrubs, wildflowers, herbs, and many
flowers grown around homes.
Kingdom Animalia
Characteristics of all animals
Multicellular
 No cell wall, no chlorophyll
 Eukaryotic
 Heterotrophs – no photosynthesis!
Other characteristics:
 Usually move around at some point in their life cycle
 Have specialized cells that serve special functions and
can form tissues, organs, and in most animals organ
systems.
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Classification
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According to structural similarities
Evolutionary relationships
Body plans
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Some are asymmetrical (no particular shape)
Some are radially symmetrical (bodies arranged
around a central point) ex. Starfish
Other have radial symmetry (you can draw a line
lengthwise down the animal’s body along only one
plane to divide it into 2 equal halves.
Body Plans
Assymetrical
Radial Symmetry
Bilateral Symmetry
Nine Main Phyla
In order from least complex to most complex:
 Porifera, Cnideria, Platyhelminthes,
Nematoda, Mollusca, Annelida, Arthropoda,
Echinodermata, and Chordata.
The first 8 make up the invertebrates or animals
with no backbones, while Chordata is the only
phyla of animals with backbones. They are
also known as vertebrates.
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Classification of Humans
Kingdom: Animalia
Phylum: Chordata
sub-phylum: vertebrata
Class: Mammalia
Order: Primate
Family: Hominidae
Genus: Homo
Species: sapiens
Scientific Name: Homo sapiens
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13.2 Invertebrates