Bio 3A Midterm 2

Prokaryote

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

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