Transcript Taxonomy review session

• Taxonomy: Branch of
biology that groups all
life according to their
characteristics and
history
• All life on earth is
placed into 1 of 6
kingdoms:
– Eubacteria
– Archaea
– Protista
– Fungi
– Plants
– Animals
• Developed classification
system based on physical
features
• Binomial Nomenclature:
System of giving every
organism 2 names
– 1st word: Genus (broad)
– 2nd word: Species (specific)
• Example: House cat
– Genus: Felis (cougars, lions,
tigers, cheetahs, etc…)
– Species: catus
• When Writing:
– Genus capitalized
– species lowercase
– Underlined entirely
Ex: Homo sapiens
• When Typing:
– Same, except use italics
Ex: Homo sapiens
• 7 individual levels (taxa)
used to classify organisms
Kingdom (broadest)
Phylum
Class
Order
Family
Genus
Species (specific)
• Allows relationships to be
clearly seen
The more levels
in common...the
more related the
species.
• Taxonomy: grouping life
according to shared traits
(not just physical)
• 1) Morphology: studying
the form and structure of
organisms
– Comparing the
morphology (traits) of
different species
shows similarities
and/or differences
Morphology Shows Non-Relationships
Also!
• Comparing DNA, amino
acids, & proteins
• DNA mutations occur at
known rates
– Splits in evolution can be
estimated based on how
different DNA between 2
organisms is
– More different the
DNA…longer ago
common ancestor
Mouth
Anus
Anus
• Patters of development studied to identify relatedness
• Blastopore (1st opening of embryo) shows humans &
starfish are more related than humans & squid
all have
amniotic
eggs
• Defined: Evolutionary history of an organism
• Shown by cladograms
– Group life according to similarities
How many traits does a primate & amphibian share?
Which organisms do not have amniotic eggs?
• 1) What does an amphibian & crocodile have in common?
Vertebrae, Bony skeleton, Four limbs
• 2) List the traits of a ray-finned fish.
Doesn’t have 4 limbs, has bony skeleton, has vertebrae
Topic 2: Viruses
• Virus: A biological particle composed of
nucleic acid and protein
• Intracellular Parasites: organism that must
“live” inside a host
• Not made of cells or
organelles
• Can’t reproduce on own
• Don’t metabolize energy
• Don’t perform cellular
processes
• Reproduce
• Have nucleic acid
• Adapt to
surroundings
• Have organization
• All Have:
– 1) Capsid: coat of
protein that surrounds
nucleic acid
– 2) Nucleic Acid: RNA
or DNA
• Some Have:
– Tail Fibers: Used for
attachment (not legs)
• Shapes vary
1st Step: Attachment
– Virus attaches to a cell receptor
– No attachment = No infection
2nd Step: Entry
– Virus enzyme weakens cell membrane
– Genetic material (DNA or RNA) enters host cell
3rd Step: Replication
– Virus DNA/RNA makes virus proteins by
transcription/ translation
4th Step: Assembly
– New virus proteins are assembled into new viruses
5th Step: Release
– Virus enzyme causes host to burst
– Viruses are released to find new host…Cycle repeats
1) Attachment: Virus attaches
to host cell
Host
Procell
phage
DNA
2) Entry: Virus nucleic acid
enter the cell, but combines
with host cell DNA.
The host
cell divides
by mitosis,
making a
copy of the
prophage
each time.
Prophage
Prophage
Two infected cells.
Prophage
Two cells divide my mitosis to make 4 infected cells.
Prophage
Prophage
Four infected cells divide by mitosis to make 8…and so on….
Virus DNA eventually becomes active and starts to create viruses following the stages of the lytic cycle.
All infected cells burst, releasing many more viruses to restart the cycle.
• Prokaryote
– Cells w/o nucleus & membrane
bound organelles
– Chromosome & plasmids float
freely in cytoplasm
• Ribosomes
– create proteins
• Flagella
– used in movement
• Pili
– act as anchors
– Connect to other cell during
conjugation
• Endospore
– “cocoon” to protect DNA in
harsh times
• Many bacteria grow in
colonies
• 3 Basic Shapes:
• 1) Rod
• 2) Spherical
• 3) Spiral
Bacteria Asexual Reproduction
Click pic
• Binary Fission: asexual reproduction where one cell splits
into two cells
– Both cells have identical sets of DNA
– Less genetic diversity
Bacteria Sexual Reproduction
Gene to resist ampicillin
Gene to resist ampicillin
• Conjugation: process where DNA is exchanged between
bacteria cells
• Cells connect by pili
• DNA duplicated and then exchanged
• Creates genetic diversity
The bacteria that causes TB
lives in your lungs…which
type is it?
• Anaerobic
– Obligate anaerobic = cannot live in oxygen
• Aerobic
– Facultative aerobic = can live with or without oxygen
– Obligate aerobic = must live in oxygen
Identifying Bacteria with Gram Staining
• Gram positive:
• stains purple
• lack extra covering
• easier to treat
• Gram negative:
• stains pink
• extra outer layer
• harder to treat
Gram Stain Overview
HEALTHY
MODERATE PERIODONTITIS
GINGIVITIS
ADVANCED PERIODONTITIS
• Problem: Bacteria are
adapting to live with the
antibiotics
• Causes:
– 1) Using antibiotics on viruses
or without prescription
– 2) Not completing prescription
– 3) Overuse on farm animals
• Importance: Bacteria
infections harder to treat
Topic 4: Protista
Protista in General
• Usually unicellular
• Reproduction:
– Asexual, Sexual, Both
• Kingdom for life that
doesn’t fit in animals,
plant or fungi kingdom
• Mostly aquatic life
• 3 main categories based on
feeding
– Animal-like
– Plant-like
– Protista-like
Animal-Like Protista (Protozoans)
• Aquatic, unicellular
• Heterotrophic
– Feed & ingest prey
– pathogens, parasites,
predators
– 3 subcategories based on how
they move
• 1) Pseudopods : have
pseudopodia (false- feet)
– Engulf by phagocytosis
• 2) Flagellates: have flagella
• 3) Ciliates: have cilia
Pseudopod (Amoeba) feeding
Pseudopod Video Clips
File title: Amoeba2
File title: Amoeba4
Ciliates Video Clip
File title: Paramecia2
File title: Rotifer2
Flagelletes Video Clip
File title: Euglena2
File title: Euglena
Animal-Like Protista
& Disease
• Malaria: Infected
mosquito bites
– Fever, vomiting,
coma, death
• Sleeping sickness:
bite of tsetse flies
– Coma & death
Plantlike Protista
• AKA: Algae
• Perform photosynthesis with
chloroplasts
– Provide ~ ½ the O2 on earth
– Most unicellular
– Phytoplankton: basis of aquatic
food chains (producers)
• Few multicellular
– Seaweed, kelp
• Why not plants?
– No true leaves, stems, or roots
– most unicellular
Fungus-like Protista
• Heterotrophs
– Decomposers: recycle nutrients
– Absorb nutrients
• Moist environments
• Slime Molds: large (~1 meter)
single celled mass of
cytoplasm
• Water molds: can be parasitic
– Potato blight: disease & the Irish
potato famine
Fungi Structure & Basics
• Hyphae: thin strands of cells that make up the fungus body
– Hyphae spread into a larger mass (mycelium)
•
•
•
•
Fruiting body: Above-ground reproductive structure
Cell wall of chiton (common to animals)
Heterotrophs: hyphae release enzymes to absorb nutrients
Classification determined by sexual reproduction methods
Zygote Fungi
• Bread Molds
• Some help “fix” nitrogen in
atmosphere
• Asexual Reproduction
– Sporangia produce spores
– Spores can grow into new
hyphae when released
. .
.
Haploid spores land
Hyphae grow into a mat of mycelium
Sporangia grow from the mycelium
Sporangia release spores
..
.
ground
The process repeats
..
.
ground
Zygote Fungi
• Sexual reproduction
– Hyphae from 2 organisms
fuse and form a diploid
zygospore
– Zygospore grows new
hyphae when released
Spores land
Hyphae grow into a mat of mycelium
ground
Hyphae of fungi grow together
Diploid zygospore is created
New diploid hyphae grow from the zygospore
Hyphae of fungus #1
Hyphae of fungus #2
Hyphae grow into a mat of mycelium….
Sporangia grow from the mycelium
Sporangia release spores
..
.
ground
The cycle repeats
ground
Hyphae of fungus #1
Hyphae of fungus #2
..
.
ground
Club Fungi
• Basidia: club-like structure that produces sexual spores
(located in gills underneath)
• Hyphae of two individuals grow into mycelium
• Fruiting body created to make spores
Club Fungi
Spores will land
Fungus #1 mycelium grows underground….Fungus #2 mycelium grows underground
Two fungi grow together and fuse
Diploid fruiting body grows from the mass
Haploid spores created & released from the underside of the fruiting body
. . .. .
ground
Spores will land
New hyphae will grow into a new mycelium
Cycle repeats
ground
Sac Fungi
• Ascus: sac that contain spores during sexual
reproduction
• Two hyphae grow together to create fruiting body
• Spores released
• Ex: Yeast, morals, truffles
Spores will land
Fungus #1 mycelium grows underground….Fungus #2 mycelium grows underground
Two fungi grow together and fuse
Diploid fruiting body grows from the mass
Haploid spores created & released from the ascus
ground
Spores will land
New hyphae will grow into a new mycelium
Cycle repeats
ground
Lichens
•
•
•
•
Fungus + blue-green bacteria or green algae
Mycelium of fungi surrounds the green organism
Grow on rocks (pioneer species), soil, trees
Mutualistic relationship
– Algae/bacteria: obtains warmth, substrate to grow in
– Fungus: obtains food
• Food source & help create soil during succession
Topic 6:
Plants
Plant Evolution
• Evolved from green algae
(450 mya)
• Green algae ancestor
– Multicellular body
– Cells w/ channels to
communicate
– Reproduce w/ sperm &
egg
• Early plants
– Low growth
(nonvascular)
Land Adaptations
• Retain Moisture
– Early plants grew near waters edge
– Cuticle: waxy coating
Land Adaptations
• Transporting Resources
– Vascular system: tissue to transport nutrients
• Up from the roots (ex: water)
• Down from the leaves (ex: sugars)
– Allows taller growth
Land Adaptations
• Growing upright
– Large plants need to support own weight
– Lignin: hardens cell wall; gives wood strength
Land Adaptations
• Reproduction on land
– Pollen: carried by wind/animals
– Seeds: hard coat protects embryo inside
Alternation of generations (In general)
• Diploid zygote created
• Diploid zygote grows into
a diploid sporophyte
• Haploid spores created by
meiosis
• Haploid spores grow into
haploid gametophytes
– Male gametophyte creates
haploid sperm
– Female gametophyte
creates haploid egg
• Sperm and egg fuse to
make a diploid zygote
• Cycle restarts
Group 1: Seedless, Nonvascular Plants
• Live in moist
environments to
reproduce
• Liverworts
• Hornworts
• Mosses
Group 1: Seedless, Nonvascular Plants
• Mosses
– Grow low to ground to
retain moisture
(nonvascular)
– Lack true leaves
– Common pioneer
species during
succession
– Gametophyte most
common (dominant)
Moss Life Cycle
1)Moss
gametophytes
grow near the
ground
(haploid stage)
2) Through water,
sperm from the male
gametophyte will
swim to the female
gametophyte to
create a diploid
zygote
3) Diploid sporophyte
will grow from zygote
4) Sporophyte will
create and release
haploid spores
...
sporophyte
zygo
egg
te
zygo
egg
te
zygo
egg
te
male male
female
zygo
egg
te
female female
gametophyte
male
female male
5) Haploid
spores land
and grow into
new
gametophytes
6) The process
repeats
gametophyte
ground
...
sporophyte
zygo
egg
te
zygo
egg
te
zygo
egg
te
male male
female
zygo
egg
te
female female
gametophyte
male
female male
Group 2: Seedless, Vascular Plants
• Vascular system allows
nutrient transport to
greater heights
• Live in moist
environments to
reproduce
• Club mosses
• Horsetails
• Ferns
Group 2: Seedless, Vascular Plants
• Ferns
–
–
–
–
Vascular: allows taller growth
Haploid spores (meiosis) on underside of fronds
Spores grow into gametophyte
Sperm & egg create a zygote
Fern Life Cycle
1) Sporophyte creates and releases haploid spores
.
.
. .
Adult
Sporophyte
(diploid)
ground
2) Haploid spores land in the soil
ground
3) From the haploid spores, gametophyte grows in the soil
Let’s zoom in
ground
4) Sperm swim through water from the male parts (antheridium) to the female parts
(archegonia)
Let’s zoom back out
zygo
egg
te
zygo
egg
te
zygo
egg
te
5) Diploid sporophyte grows from the zygote
sporophyte
ground
6) Fronds uncurls into leaves.
7) Cycle repeats
-- Haploid spores created and released
.
.
.
ground
.
Haploid spores land in the soil
ground
From the haploid spores, gametophyte grows in the soil
Let’s zoom in
ground
Sperm swim through water from the male parts (antheridium) to the female parts
(archegonia)
Let’s zoom back out
zygo
egg
te
zygo
egg
te
zygo
egg
te
Diploid sporophyte grows from the zygote
sporophyte
ground
Fronds uncurls into leaves.
Cycle repeats
.
.
.
ground
.
Seeds and their advantages
• 1) Seed plants don’t depend
on water to reproduce
– Pollen (contains sperm)
combines with egg
– Egg hardens into a seed
• 2) Nourishment and
protection
– Nourish: Nutrients inside
seed for the embryo
– Protection: Hard shell
• 3) Allow dispersal
– Carried by wind, water,
animals
Group 3: Seed producing, Vascular Plants
• Type 1: Gymnosperms
• Seeds not enclosed in a
fruit
– produced inside cones
• Cone = reproductive
structure
• Male cones: produce
pollen
• Female cones: produce
eggs and seeds
Group 3: Seed producing, Vascular Plants
• Gymosperm example:
Conifers
– Cone plants
– Needle-like leaves
– Common to lumber
industry
– Evergreen, Pine,
Redwood, Cedar
Conifer Life Cycle
1) Male and female seed cones grow in adult sporophytes
2) Pollen grains released from the male seed cones
-- Pollen is the male gametophyte
Male cones make pollen
Female cones make eggs
zygo
egg
te
zygo
egg
te
zygo
egg
te
zygo
egg
te
seed
seed
seed
seed
3) Seeds begin to harden inside the female cones
4) Seeds released
5) Seed will land
ground
6) Seedling grows into (sporophyte)…the cycle repeats
ground
1) Male and female seed cones grow in adult sporophytes
Male cones make pollen
Female cones make eggs
zygo
egg
te
zygo
egg
te
zygo
egg
te
zygo
egg
te
seed
seed
seed
seed
3) Seeds begin to harden inside the female cones
4) Seeds released
5) Seed will land
ground
6) Seedling grows into (sporophyte)…the cycle repeats
ground
Group 3: Seed producing, Vascular Plants
• Type 2: Angiosperms
(flowering plants)
• Flower = reproductive
structure
– Protects gamete and
fertilized eggs
• Seeds enclosed in a fruit
– Fruit: Plant ovary
– Often attract animals
to disperse the seeds
inside
Fruit Production
• In the seed
– Embryo
– Food supply
• Surrounding ovary grows into a
fruit
• Fruit attracts animals to eat and
spread the seeds
Fruit seeds in fox droppings
Angiosperm types
(flowering plants)
•
•
•
•
2 groups: Monocots and Dicots (based on seed type)
Cotyledon: embryonic leaf
Monocots: embryo with 1 seed leaf
Dicots: embryo with 2 seed leaves
Angiosperm Life Spans
• Three Life Span Types:
• Annuals
– 1 year: Mature…produce
seeds…die
• Biennials
– 1st year: produces short stem,
low growth leaves, food
reserves
– 2nd year: taller stem, leaves,
flowers, seeds
• Perennials
– Live for more than 2 years
Flowers
• Reproductive structure
of flowering plants
• Sepals
– outer ring of leaves
– protection
• Petals
– Inner ring of leaves
– Brightly colored to
attract pollinators
• Open petals & sepals
reveal male and female
structures
Flowers
• Female Carpel
– Inner most part
– Ovary: within the
base (female
gametophyte)
– Stigma: sticky tip,
collects pollen
• Male Stamen
– Surrounds carpel
– Anther: produces
pollen (male
gametophyte)
Angiosperm Life Cycle
Pollen stick to animal or released
into wind
Animal finds a new flower to feed
on
Pollen transferred to the stigma….seeds develop
zygo
egg
te
Flower petals start to fall off and dies
zygo
te
Fruit falls to ground
Animals eat fruit….seeds come out the other end…cycle repeats
seed
Pollen stick to animal or released
into wind
Animal finds a new flower to feed
on
Pollen transferred to the stigma….seeds develop
zygo
egg
te
Flower dies
zygo
te
Fruit falls to ground
Animals eat fruit….seeds come out the other end…cycle repeats
seed
End of the Semester!