Kingdoms, Classification, and
Plants
Unit 8
Taxonomy
• There are estimated to be 10-30 million organisms on
Earth.
– Can you remember this many names?
• Taxonomy: the science of naming and classifying
organisms
• Over 2,000 years ago, Greek philosophers grouped plants
and animals into units of classification called a genus
(plural: genera).
• This could get confusing if people didn’t agree on names!
Carl Linneaus: created a system for naming organisms.
 Binomial nomenclature: Linneaus’ two-word system for naming organisms
• Binomial nomenclature uses two Latin words to name each
organisms. The first word is the genus, the second is the
species name.
• Example: Apis mellifera or the European Honeybee
– Apis=genus name
– Mellifera=species name
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Scientific Names
• These two part names are now called “scientific names.”
• Genus: a taxonomic category containing similar species.
Organisms in a genus share important characteristics.
• Species: the basic biological unit in the Linnaean system of
classification.
• Scientific names are important because this common
language for biologists prevents confusion if organisms have
different “common” names in different places. A “Robin” is a
different bird here than in England, so we need scientific
names to keep everything straight!
• Rules:
–
–
–
–
The first letter of the genus is capitalized.
The first letter of the species is lowercase.
Italicized or underlined.
Once you use the full name, you can abbreviate it like this:
• Genus species  G. species
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Scientific Name Practice!
• Write the following names in the proper format,
then write the abbreviation.
• Red Oak: quercus rubra
– Quercus rubra Q. rubra
• Human: homo sapiens
– Homo sapiens H. sapiens
• Chimpanzee: pan paniscus
– Pan paniscus  P. paniscus
• Honeybee: apis mellifera
– Apis mellifera  A. mellifera
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Classifying Organisms
• There are eight levels of classification;
each level is more inclusive than the
previous.
• Similar genera are grouped into a family.
• Similar families are grouped into an order.
• Similar orders are grouped into a class.
• Similar classes are grouped into a phylum.
• Similar phyla are grouped into a kingdom.
• Similar kingdom are grouped into
domains.
• Domain Kingdom Phylum Class Order
Family Genus Species
• Do Kindly Pay Cash Or Furnish Good
Security
• Daring Kings Play Chess On Fine Green Silk
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Levels of Classification
• Each level is more inclusive than the previous.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Domains
• Domain: the most inclusive unit of taxonomic
classification.
• All living organisms are grouped into one of three
domains!
1. Archaea: a single kingdom of prokaryotes
(archaebacteria).
2. Bacteria: a single kingdom of prokaryotes (eubacteria).
3. Eukarya: four kingdoms of eukaryotes.
1.
2.
3.
4.
Protista
Fungi
Plantae
Animalia
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K
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Kingdoms
• There are 6 Kingdoms, in 3 different Domains:
– Domain Archaea:
• Kingdom Archaebacteria: prokaryotes that seem to have diverged very
early from bacteria. More closely related to Eukaryotes than bacteria.
– Domain Bacteria:
• Kingdom Eubacteria: prokaryotes that have the same kind of lipid in
their cell membranes as do eukaryotes.
– Domain Eukarya:
• Kingdoms:
– Protista: Eukaryotes that are not fungi, plants, or animals.
Unicellular or multi-cellular.
– Fungi: mostly multi-cellular eukaryotes with chitin in their cell walls.
– Plantae: complex multi-cellular organisms that produce their own
food.
– Animalia: complex multi-cellular organisms that eat other
organisms for food.
» Vertebrates: an animal with a backbone
» Invertebrates: an animal with no backbone
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Domains and Kingdoms
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Nutrition in Kingdoms
• Autotrophic: an organism that
produces its own nutrients from
inorganic substances or from the
environment instead of consuming
other organisms.
– Makes its own food!
• Heterotrophic: an organism that
obtains organic food molecules by
eating other organisms or their by
products and that cannot
synthesize organic compounds
from inorganic materials.
– Eats food!
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http://en.wikipedia.org/wiki/Autotroph
http://ed101.bu.edu/StudentDoc/current/ED101fa10/ccburke/Organisms.htm
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What is a Species?
• Biological Species Concept: a species is a group of natural
populations that are interbreeding or that could interbreed,
and that are reproductively isolated from other such groups.
– Species are reproductively isolated from others though
reproductive barriers.
– However, these reproductive barriers may not always be
complete.
• Example: Wolves and dogs can interbreed but are in different species.
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Evolutionary History
• Darwin said that organisms that are more similar to one
another have descended from a recent common
ancestor.
• Classification should reflect an organism’s phylogeny.
– Phylogeny: evolutionary history
• Not all features come from common ancestors!
– Through convergent evolution, similarities called
analogous structures evolve. Such structures do not come
from common ancestors.
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Cladistics
• Most biologists today analyze evolutionary
relationships using cladistics.
– Cladistics: a method of analysis that reconstructs
phylogeny (evolutionary relationships) by inferring
relationships based on shared characters.
• This is done using:
– Ancestral Characters: traits that evolved in a common
ancestor of both groups.
• Backbones in birds and mammals are an ancestral character
because the backbone was present in a common ancestor.
– Derived Characters: traits that evolved in an ancestor
in one group but not in an ancestor of another.
• Feathers evolved in an ancestor of birds. This ancestor was
NOT an ancestor to mammals.
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Cladistics
• Cladogram: a branching diagram that shows the
evolutionary relationships among a group of
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organisms. Example:
Phylogenetic
Tree
Cladogram
Clades and Evolution
• Organisms are assigned to different taxonomic
categories based on their shared derived
characteristics.
• Cladograms show how closely two or more
groups are related based on these important
characteristics.
• Organisms that are grouped more closely share a
more recent common ancestor than those far
apart.
• A clade demonstrates the evolutionary ancestor
and all its descendents based on shared derived
characters.
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Phylogenetic Tree
• Phylogenetic Tree: A branching diagram that displays
evolutionary relationships based on a subjective
analysis of various characters.
Phylogenetic
Tree
Cladogram
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Dichotomous Keys
• A dichotomous key is a written device used to
allow a scientist or individual to determine the
species of an organism or identify an object.
• Dichotomous keys help individuals apply the
classification system and identify the groups
to which an organism belongs.
• Dichotomous keys are based on an idea: an
organism either has or does not have a
particular trait.
Complex Multi-cellularity
• Some organisms, such as plants and animals demonstrate complex
multicellularity and are organized into:
– Tissue: distinct group of cells with a similar structure and function
– Organs: tissues organized into a specialized structure
– Organ Systems: organs organized into a system that carries out a
major function.
– SO: organ systems are made of organs which are made of tissues
which are made of cells!
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Adaptations of Plants
• The first plants lived near
water, where drying out was
not a problem.
• Eventually, plants developed
traits to allow them to live in
drier habitats.
– Cuticle: a waxy, watertight
covering that reduces water loss
• Covers the non-woody
aboveground plant parts
– Stomata (singular: stomata):
pores that permit plants to
exchange oxygen and carbon
dioxide.
– Guard Cells: Specialized cells
that border stoma
• Stomata open and close as the
guard cells change shape
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Plant Tissue Types
1. Dermal Tissue: the
protective outer layer of
a plant.
2. Ground Tissue: makes
up much of the inside of
the non-woody parts of
a plant, including roots,
stems, and leaves.
3. Vascular Tissue: tissues
that distribute materials
efficiently through the
plant
– Xylem
– Phloem
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Conducting Tissue
(Vascular Tissue)
• Vascular Plant: a plant with a
vascular system
– Vascular system: a system of welldeveloped vascular tissues that
distribute materials efficiently
through the plant in larger, complex
plants.
• Non-vascular Plant: a plant with
no vascular system.
• Types of Vascular Tissue:
– Phloem: soft-welled cells that
transport organic nutrients
– Xylem: hard-walled cells, transport
water and mineral nutrients
– The Xylem and the phloem are
contained in a strand of conducting
tissue called the Vascular Bundle.
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Root Conducting Tissue
• Plants developed roots to absorb nutrients
– Roots are made of 3 types of tissue:
1. Epidermis: the outside layer
2. Vascular tissue: the conducting tissue, contains the xylem
and phloem
3. Cortex tissue: stores sugar and starch
– All roots have a protective covering at the end
of the root called a root cap, And tiny root hairs
along the side of the root that increase
absorption of nutrients by increasing surface
area.
– Roots are divided into 2 categories based upon
shape.
• Tap roots: large central roots from which many
smaller roots branch
• Fibrous root: highly branched root system
• Additionally, some plants also have roots that grow
from aboveground stems or leaves, which are called
adventitious roots.
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Kinds of Plants
• Nonvascular Plants: plants with no vascular
tissue
• Seedless Vascular Plants: vascular plants that
do not produce seeds
• Gymnosperms: seed plants who seeds do not
develop within a sealed container (fruit)
• Angiosperms: flowering seed plants that
produce seeds enclosed a specialized
structure called a fruit
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Nonvascular Plants
•
•
•
•
•
Nonvascular Plants: plants with no vascular tissue
Lack true roots, stems, and leaves
Small size, Larger gametophyte
Require water for sexual reproduction
Kinds of nonvascular plants:
– Mosses
– Liverworts
– Hornworts
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Seedless Vascular Plants
• Seedless Vascular Plants:
vascular plants that do not
produce seeds
• Vascular system
• Larger sporophyte
• Drought-resistant spores
• Kinds of Seedless Vascular
Plants:
– Ferns
– Club mosses
– Horsetails
– Whisk ferns
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Gymnosperms
• Gymnosperms: seed plants
who seeds do not develop
within a sealed container
(fruit)
• Have seeds
• Have greatly reduced
gametophyte
• Wind pollination
• Kinds of gymnosperms:
–
–
–
–
Conifers
Cycads
Ginkgo
Gnetophtes
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Angiosperms
• Angiosperms:
flowering seed plants
that produce seeds
enclosed a specialized
structure called a fruit
• Flowers
• Fruits
• Endosperm
• Kinds of angiosperms:
– Monocots
– Dicots
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Monocots and Dicots
• Monocots and dicots are different
types of ANGIOSPERMS!
• Monocots: flowering plants that
produce seeds with one seed leaf
– Most monocots also produce flowers
with parts that are in multiples of
three
– Have long, narrow leaves with parallel
veins
• Dicots: flowering plants that produce
seeds with two seed leaves
– Most dicots produce flowers with
parts in multiples of two, four, or five
– Have leaves with branching veins
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Examples of Monocots and Dicots
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Legumes: a Dicot
• Legumes are members of the
pea family.
• Produce protein-rich seeds in
long pods.
• Soybeans, peas, peanuts, alfalfa
are all legumes.
• Many legumes have nitrogenfixing bacteria which add
nitrogen compounds to the soil,
enriching the soil
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http://www.dietriffic.com/2007/09/09/what-are-legumes/
Plant Tissue Types
1. Dermal Tissue: the
protective outer layer
of a plant.
2. Ground Tissue:
makes up much of
the inside of the nonwoody parts of a
plant, including roots,
stems, and leaves.
3. Vascular Tissue:
tissues that distribute
materials efficiently
through the plant.
–
–
Xylem
Phloem
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Dermal Tissue
• Dermal tissue is the
outside of the plant
body
• Epidermis: the outer
surface layer of cells
– In most plants, this is
made up of a single layer
of flat cells.
– On top of the epidermis,
there is the cuticle.
• Cork: the outer layer of
bark of any woody plant
– Contain a waterproof
chemical and are not
covered by a waxy cuticle
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Ground Tissue
• Makes up most of the
inside of plants.
• Can have different
functions:
– Leaf Ground Tissue: full
of chloroplasts for
photosynthesis
– Stem Ground Tissue:
stores water, sugar, and
starch.
– Root Ground Tissue:
sores water, sugar, and
starch.
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Vascular Tissue: Xylem
• Xylem is composed of Thickwalled cells that conduct
water and mineral nutrients
from a plant’s roots through
its stems to its leaves.
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Vascular Tissue: Phloem
• Phloem contains cells
that conduct sugars
and other nutrients
through-out a plants
body.
• The conducting strands
in phloem are called
sieve tubes.
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Roots
• Plants developed roots to absorb nutrients
– Roots are made of 3 types of tissue:
1. Epidermis: the outside layer
2. Vascular tissue: the conducting tissue, contains the xylem and phloem
3. Cortex tissue: stores sugar and starch
– All roots have a protective covering at the end of the root called a
root cap, And tiny root hairs along the side of the root that
increase absorption of nutrients by increasing surface area.
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Stems
• Support the leaves and house the
vascular tissue.
• Pith: the ground tissue inside the
ring of vascular bundles.
• There are two types of stems:
– Nonwoody stems: belong to plants
called herbaceous plants
• Vascular bundles are surrounded by
ground tissue.
– Woody stems: stiff and nongreen
stems.
• Layers of xylem are on inner rings and
make up most of the wood.
• Woody stems are protected by cork.
• Cork and phloem make up the bark of the
tree.
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• Leaves function mostly
to allow the plant to
perform photosynthesis.
THIS IS WHERE THE
SUNLIGHT IS ABSORBED!
• Mesophyll: the ground
tissue of the leaf, which
are packed with
chloroplasts which allow
cells to perform
photosynthesis and make
the leaves look green.
• Levels of organization:
Leaves
– A plant organ, such as a
leaf:
• contains tissues
including vascular
(xylem and phloem),
ground (mesophyll), and
dermal (epidermis).
– Each tissue is made of
different types of cells.
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Flowers
Male Parts:
•Anther: the tip of the stamen,
which contains the pollen sacs
where pollen grains form.
•Filament
•The anther and filament
together make up the stamen.
Female Parts:
•Stigma: the segment of the
female portion of the flower
where pollen grains are received.
•Style
•Ovary
•The stigma, style, and ovary
together make up the pistil.
Other Parts:
•Petal
•Sepal
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Movement of Water
• Water moves from the roots to the leaves in the xylem.
• Basically, water is pulled up through the plant through
transpiration pull as water evaporates.
• Transpiration: the loss of water vapor from a plant
• Root Pressure: root pressure, in plants, force that helps
to drive fluids upward into the water-conducting
vessels (xylem)
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Guard Cells and Transpiration
• A stoma is surrounded by a pair of guard cells that are shaped like
two cupped hands.
• Changes in water pressure within in the guard cells cause the
stoma to open or close.
• When the guard cells take in water, the swell, opening the stoma
an allowing transpiration to occur.
• When water leaves the guard cells, the shorten and move close to
each other, closing the stoma and stopping transpiration.
• Guard cells regulate transport and transpiration.
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Movement of Organic Compounds
• Organic compounds move through
a plant within the phloem.
• Source: the part of a plant that
provides organic compounds for
other parts
– A leaf is a source because it makes
starch in photosynthesis
• Sink: the part of a plant that
organic compounds are delivered
to
– Actively growing areas are sinks
because they need sugar to grow
• Translocation: the
movement of organic
compounds within a plant
from a source to a sink
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02/27/13 DOL: For each image below,
identify the tissue type or structure!
1.
4.
2.
3.
5.
Alternation of Generations
• Plants, algae, and
some protists have
a life cycle that
regularly
alternates
between a haploid
phase and a
diploid phase.
• Sporophytes: the
diploid phase that
produces haploid
spores
• Gametophyte: the
haploid phase that
produces gametes
by mitosis
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Terminology Review
• Mitosis: in eukaryotic cells, a process of cell division
that forms two nuclei, each of which has the same
number of chromosomes.
• Meiosis: a process in cell division during which the
number of chromosomes decreases to half the original
number by two divisions in the nucleus (makes sex
cells).
• Haploid (n): a cell that has only one set of unpaired
chromosomes (one copy of each chromosome).
• Diploid (2n): a cell that contains two haploid sets of
chromosomes (two copies of each chromosome).
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Moss Life Cycles
• Sexual reproduction results
in a fertilized egg or zygote.
• The diploid zygote grows
into a diploid sporophyte.
• A moss sporophyte grows
from a gametophyte and
remains attached to it.
• The sporophyte makes
haploid spores through
meiosis.
• The spores grow into
gametophytes where
archegonia and antheridia
form.
• Archegonia and antheridia
make sperm and eggs.
Moss Life
Cycle
In mosses, the gametophyte stage of the
life cycle is larger than the sporophyte
stage.
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Fern Life Cycle
• A fertilized egg or zygote
grows into a sporophyte.
• The diploid sporophyte
produces spores by meiosis.
• The haploid spores fall to the
ground and grow into
haploid gametophytes.
• Fern gametophytes produce
gametes by mitosis.
• Sperm from the antheridia
swim to the archegonia and
fertilize the eggs.
• In ferns, the sporophyte
stage is what you think of as
a fern. The gametophytes
are very small.
Fern Life
Cycle
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Pollination
• Pollination: the transfer of pollen grains from
the male reproductive structures of a plant to
the female reproductive structures of a plant.
– Pollination is how plant seeds are produced seed
plants.
Pollination
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Seeds Sprout
• Seeds contain a plant embryo that is in a state of
suspended animation.
• Seeds sprout with a burst of growth in response to
certain changes in the environment.
– Examples: rising temperature, increased moisture
• Endosperm: a triploid tissue that develops in the
seeds of angiosperms and that provides food for a
developing embryo
Seeds
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Double Fertilization in Angiosperms
• Fertilization is different in angiosperms.
• The male gametophytes (pollen grains) are made
on the anther of a stamen. A pollen grain has two
sperm cells.
• One sperm fuses with the haploid nuclei of two
other cells produced by meiosis.
• The fusing of three haploid (n) cells makes a triploid
(3n) cell that develops into endosperm, which is a
triploid tissue that develops in the seeds of
angiosperms and that provides food for a
developing embryo.
• This process is known as double fertilization.
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Germination
• Germination: the beginning of growth or
development in a seed, spore, or zygote,
especially after a period of inactivity.
– In plants: when the embryo in the seed starts
growing!
Germination
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Stems Modified for Vegetative
Reproduction
Most plants can
reproduce sexually and
asexually.
When plants are made
asexually, they are
genetically the same as
the parent plant.
The reproduction of
plants from nonreproductive parts such
as the stems, roots, and
leaves is called
vegetative reproduction.
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Plant Propogation
Growing new plants from seed or from
vegetative parts is called plant
propagation.
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Meristems
• Meristem: a region of undifferentiated plant cells that are
capable of dividing and developing into specialized plant
tissues.
• Primary Growth: growth that increases the length or height
of a plant.
– Apical Meristems: located at the tips of stems and roots, produce
primary growth through cell division.
• Secondary Growth: growth that increases the width of stems
and roots.
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Hormonal Control of Growth
• Plants bend
toward light as
they grow.
• Auxin: the
chemical that
causes the
stem to bend
towards light.
• Other plant
growth
hormones:
– Gibberellins
– Abscisic Acid
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Tropisms
• Tropism: a response in which a plant grows either toward
or away from a stimulus.
• Four Types of Tropisms:
– Phototropism: responses to light
• A plant bends towards light, this is called positive
phototrophism.
– Gravitropisms (Geotropism): responses to gravity
• The upward growth of shoots is a negative gravitropism; the
downward growth of roots is a positive gravitropism.
– Thigmotropism: response to touch
• The coiling of a grapevine around a wire is thigmotropism.
– Hydrotropism: response to water
• The growth of roots towards water is positive hydrotropism.
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