Bio 3A Midterm 2

Prokaryote

All Bacteria and Archaea.

lack a membrane-bound nucleus, mitochondria, or any other membrane-bound organelle

Protists

all eukaryotes except plants, animals, and fungi

Prokaryote - Cell shape

Cocci - Spherical (round)
Bacilli - rod
Spirochete - spiral

Cocci - Spherical (round)

Form chains
Ex: Streptococci and Strept Throat

Form clusters
Ex: Staphylococci and/or Staph infection

Bacilli - rod

Most occur alone
which can cause food poisoning

Some occur in pairs or chains

Spirochete - spiral

Usually alone
Ex: Lyme disease and/or syphilis

Prokaryote - Cell walls

Nearly all prokaryotes have a cell wall which provides protections
Two types
1. Peptidoglycan
2. Lipids and carbs
Many have a capsule
Archaea
-No peptidoglycan but can be G+ or G-

What types of cell walls do bacteria have?

1. peptidoglycan (gram positive)
2. Lipids and carbs (gram negative)

Capsule

Allows bacteria to stick to things and each other

Prokaryote - projections

External structures
Flagella
Fimbriae

Flagella

whip like structure that enables swimming

Fimbriae

hair like projections• Help them stick to other things

Photoautotrophs

Capture energy from sunlight (Photo)
Use CO2 for carbon
Cyanobacteria (blue green algae)

Photoheterotrophs

Capture energy from sunlight (Photo)
Obtain carbon from organic sources (complex molecules)
Purple non-sulfur bacteria (Found in aquatic sediments)

Chemoautotrophs

Capture energy from inorganic chemical (not carbon based)
Use CO2 for carbon
Can live in extreme environments (Hydrothermal vents) or regular environments (soil)

Chemoheterotrophs

Capture energy from inorganic chemical (not carbon based)
Obtain carbon from organic sources (complex molecules)
Largest and most diverse group
Eats pretty much anything

Symbiosis

a close association among two or more organisms

What are the 4 key bacteria groups

1. Proteobacteria
2. Gram-positive bacteria
3. Cyanobacteria
4. Spirochetes

1. Proteobacteria

Gram negative
Nutritionally diverse
-Photoautotroph
-Photoheterotroph
-Chemoautotroph
-Chemoheterotroph
Pathogens
Ex: Coli or salmonella
Symbiosis

2. Gram-positive bacteria

Gram positive
Nutritionally diverse
-Photoautotroph
-Photoheterotroph
-Chemoautotroph
-Chemoheterotroph
Pathogens
Ex: Strept throat or Staph infections

3. Cyanobacteria

Gram negative
Photoautotroph
Caused the first mass extinction
Toxic Blooms!

4. Spirochetes

Gram negative
Chemoheterotrophs
Pathogens
Ex: Lyme disease or Syphilis
Spiral shaped

What are the two main branches of prokaryotic evolution

Bacteria and Archaea

Archaea

Thrive in extreme environments
Halophiles - salt loving
Thermophiles - heat loving
Methanogens - live in anaerobic (no oxygen) conditions and produce methane as waste

Protists have diverse nutrition - Autotrophs

Photosynthesize

Protists have diverse nutrition - Autotrophs

Eat other things

Protists have diverse nutrition - Mixotrophs

Both

What are the supergroups of protist diversity

1. SAR
2. Excavata
3. Unikonta
4. Archaeplastida

What are the 3 ranges of the SAR supergroup of protist diversity

1. Stramenopila
2. Alveolata
3. Rhizaria

1. SAR - Stramenopiles

Diatoms
-Unicellular algae
-Autotrophs
-Cell walls contain silica
-Found in aquatic environments

Brown algae (sea weed)
-All multicellular
-Autotrophs
-Mostly Marine

Water molds
-Unicellular
-Heterotrophs
-Decompose dead plants

1. SAR - Alveolates

Dinoflagellates
-Unicellular
-Autotrophs, heterotrophs, mixotrophs
-Red tide (nickname)

Ciliates
-Use cilia to get food
-Paramecium

1. SAR - Rhizarians

Foraminiferans
-Most are fossils (90%)
-Aquatic (fresh and marine)
-Shells hardened with calcium

Radiolarians
-Most are marine
-Skeletons hardened with Calcium

2. Excavata

"Excavated" feeding groove
Autotrophs, Heterotrophs, mixotrophs
Parasites

3. Unikonta

Amoebozoans
-Heterotrophic
-Closely related to fungi and animals
-Free living amoebas
-Parasitic Amoebas
-Slime molds

4. Archaeplastida

Autotrophic
Mostly multicellular
Red Algae
-Mostly multicellular
Green Algae (more seaweed)
-Lichens
-Alternation of generations

Alternation of generations

Multicellular haploid and diploid individuals
-Sporophyte: produces spores
-Gametophyte: produces gametes

Fungi

C

Absorption

they secrete enzymes that digest plants and animals and then absorb the small nutrients

Fungi structures

fungus usually consists of a mass of threadlike filaments called hyphae, which branch repeatedly as they grow, forming a mycelium

Hyphae

mass of threadlike filaments

mycelium

densely branched network of the hyphae of a fungus

What lifecycles do fungi have?

Asexual and sexual lifecycles

Decomposers

organisms that break down wastes and dead organisms and return raw materials to the environment

What are the 5 groups of fungi

1. Chytrids
2. Zygomycetes
3. Glomeromycetes
4. Ascomycetes
5. Basidiomycetes

1. Chytrids

Only fungi with flagellated spores
Common in lakes and ponds
Decomposers and Parasites
Causing an amphibian mass extinction

2. Zygomycetes

Mostly terrestrial
Mostly decomposers
Characterized by presence of zygosporangium
A few parasites on animal

3. Glomeromycetes

Characterized by mycorrhizae which invade plant cells
-Symbiosis
-80% of the plants on earth have this symbiosis

Mycorrhizae

Helped plants colonize land
Trade
-plant get nutrients (nitrogen and phosphorus)
-Fungus gets carbon but not always

4. Ascomycetes

Characterized by sac like structure called asci that produces spores in sexual reproduction
Marine, freshwater, or terrestrial
Decomposers
Plant pathogens
Lichens

Lichens

A symbiosis between an Ascomycete and a cyanobacteria or green algae

5. Basidiomycetes

Mushrooms
Characterized by a basidium - spore producing structure (mushroom)
Decomposers
-especially wood
Parasites

What are the four key events in the history of the plant kingdom?

1. Origin of land plants
2. Origin of vascular plants
3. Origin of seed plants
4. Origin of flowers

1. Origin of land plants

Living on land presented several challenges
Drying out - no longer surrounded by water
Obtaining resources from two sources
Support (Not falling over)
Reproduction and Dispersal

1. Origin of land plants: Drying out

Plants evolved a waxy cuticle to keep from drying out.
This prevents gas exchange
-Need CO2 for photosynthesis
-Release O2 as waste
Stomata

Stomata

tiny pores in the leaves of plants that open and close to let CO2 in and let O2 out

1. Origin of land plants: Obtaining resources from two sources

Get everything they need from soil or from the air
Roots
Stems - (Support)
Leaves
Vascular Tissue connects it all
-Xylem: pulls water up from roots
-Phloem: distributes sugars

1. Origin of land plants: Reproduction and Dispersal

Different approaches for different plants represent the evolutionary history of plants
Reproduction
-All plants have alternation of generations

Dispersal
-Moss and ferns: water
-Gymnosperms (cone bearing plants): wind, gravity, animals
-Angiosperms (flowering plants): wind, ants, mammals, birds, water, gravity, etc.

2. Origin of vascular plants

First Plants were bryophytes (non-vascular plants)

What are some characters of bryophytes

Do not have true roots
-Have Rhizoids
Do not have true leaves (Phyllid)
Do not have lignin for structural support
Grow flat in dense mats
Must have water for fertilization

Moss

Have stomata
Multicellular rhizoid

Liverworts

Have stomata only on the sporophyte
Multicellular rhizoid
Some are parasitic

Hornworts

Produce slime
Only have one chloroplast per cell
Chloroplast

chloroplast

Cell that does photosynthesis

What are some characteristics of seedless vascular plants?

Have true roots
Have leaves
Have lignin for structural support
Grow upright
Have vascular tissues
Must have water for fertilization

Vascular tissue - Xylem

Transports water and minerals from the roots to aerial parts of the plant (moves only up)
Vessel wall consists of fused cells that create a continuous tube
Vessels are composed of dead tissue and are hollow

Vascular tissue - Phloem

Transports food and nutrients to storage organs and growing parts of the plant (moves up and down)
Vessel wall consists of cells that are connected at their ends to form porous sieve plates
Vessels are composed of living tissue, however sieve tube elements lack nuclei and have few organelles

Club Moss (lycophyte)

Small leaves with one vein
Dominant during Carboniferous (359.2 to 299 MYA)

Ferns (monilophyte)

Large leaves, many veins

3. \

2 key groups
-Gymnosperms
-Angiosperms

No longer need water to reproduce
-Pollen: carries sperm through the air
-Gametophyte and Sporophyte not separate plants

What are some Gymnosperms (cone bearing) species?

1. Ginkgo
2. Cycad
3. Ephedra
4. Conifers

What are conifers?

Leaves in "needles"
Seeds in cones
-Separate male and female cones

Evergreen (mostly): doesn't drop leaves
All woody
-Secondary growth: increase of thickness and growth of plant

All tree and shrubs
No ovaries

4. Origin of flowers - Angiosperms (flowering plants)

C

Floral morphology

Flowers usually consist of
-sepals
-Petals
-Stamens
-carpels

Flowers consist of - Sepals

which enclose the flower before it opens

Flowers consist of - Petals

which often attract animal pollinators

Flowers consist of - Stamens

male reproductive structures
-Filament
-Anther: contains pollen

Flowers consist of - Carpels

the female reproductive structures
-Stigma
-Style
-Ovary

Dispersal

The worst place for a seed is next to the parent
Many adaptations to move

What are the adaptations relating to dispersal?

Wings - wind dispersal
Burs - Mammal dispersal
Fruits - Bird and mammal dispersal
**Elaiosomes - Ant dispersal**
Buoyancy - water dispersal

What are fruit relating to plants?

modified ovaries that develop after seeds are fertilized

Pollination

A key step in the lifecycle of an angiosperm is getting the pollen to the stigma
Symbiosis
Coevolved
Pollination syndromes

Pollination syndromes

Similarities among flowers that share the same pollinators

What are some example of pollination syndromes?

Birds - bright red and orange flowers, no scents
Bees - Marked with UV guides that lead to nectar
Bats and moths - white flowers, highly scented, bloom at night
Wind - no flowers, no scents

Monocot and Eudicot

What are the two major groups of angiosperms

Cotyledons

embryonic leaves that form in the seed
-Monocot: one cotyledon
-Eudicot: two cotyledons

Monocot
-parallel veins
Eudicot
-Branched veins

Vascular tissues: Leaf veins (Monocot and Eudicot description)

Monocot
-Scattered vascular bundles
Eudicot
-Vascular bundles in rings

Vascular tissues: Steams (Monocot and Eudicot description)

Monocot
-Parts in multiples pf 3s
Eudicot
-Parts in multiples of 4 or 5

Flowers (Monocot and Eudicot description)

Monocot
-Fibrous root system (No main root)
Eudicot
-taproot (main root present)

Roots (Monocot and Eudicot description)

Root
Shoot
Leaf

What are the 3 systems that plants are comprised of?

Plant System: Root

Anchors the plant to the soil (fibrous and taproots)
Absorbs and transports minerals and water
-Facilitated by root hairs: increase surface area
Taproots
-stores carbs

Plant System: Root

Large taproots that store food
Ex: Carrots, turnips, beets, sweet potatoes (Not regular)

Plant System: Leaf

Primary site for photosynthesis
Consist of a
-Blade: the leaf
-Petiole: joins blade to the stem at a node

Modified Leaf

Spines: a modified leaf that protect the plant from being eaten
Tendrils: modified leaves that help vines "climb"

Plant System: Shoot

Stems: organ that has the leaves and buds on it
-Can photosynthesize
-Nodes
-internode
Buds: are undeveloped stems
-terminal bud
-axillary bud

Nodes

points at which leaves are attached

Internode

space between the nodes

terminal bud

primary growing point for getting taller

Axillary bud

between stem and leaf, usually dormant

Modified shoot

Stolon: horizontal stem aboveground
-allows for asexual reproduction (cloning)
Rhizome: horizontal stem belowground
-store food, can form new plants
Tuber: specialized storage structure
Succulence: stores water