UNCW BIO 202 Plant Exam #2

What is a paraphyletic group of taxa belonging to 7 subgroups?

Protists

What are protists artificially grouped by?

1. Ecological Role

2. Habitat

3. Motility Type

What are the types of ecological roles protists play?

1. Algae

2. Protozoa

3. Fungus-Like

Ecological Role: Algae

Autotrophs that produce oxygen. Also an important renewable biofuel.

Ecological Role: Protozoa

Heterotrophs that eat by absorbing

Ecological Role: Fungus-Like

Heterotrophs that share some traits via convergent evolution

What are the "habitats" protists can occupy?

1. Plankton

2. Aquatic Substrate

What are the different motility types of protists?

1. Flagellates

2. Ciliates

3. Amoebae

Motility Type: Flagellates

Most are unicellular with flagellum

Motility Type: Ciliates

Cilia for movement, can be larger than flagellates

Motility Type: Amoebae

Crawling movement by protrusion of cytoplasm via pseudopodia

Protist Supergroup: Excavata

Have an excavated feeding groove where food particles are collected in the groove and are consumed by phagocytosis.

Excavata: Parasites

Trichomonas vaginalis and Glardia intestinalis

Excavata: Euglenoids

Colorless, lack chloroplasts.

Have a light sensing eyespot.

Found in wetlands.

Excavata: Kinetoplastids

Heterotrophic

Kintetoplast = circular DNA in large mitochondria

Some are parasites: leishmania and trypanosome brucei

Protist Supergroup: Land plants and related algae

3 types:

1. green algae

2. rhodophyta

3. cryptophyta

Land Plants/Related Algae: Green Algae

Morphologically diverse

Flagellate cells

Chlorophyll A, B, and Plastids

Land Plants/Related Algae: Rhodophyta

Red Algae

Marine only

No flagellate cells

Chlorophyll A, B, and red photosynthetic pigments

Land Plants/Related Algae: Cryptophyta

Marine and freshwater

Unicellular

Protist Supergroup: Alveolata

Contain series of saclike vesicles forming a continuous layer under the cell membrane

Alveolata: Cilophora

Ciliate

Mostly unicellular

Cytosome (cellular mouth)

Cytoproct

Alveolata: Apicomplexa

Appeal complex cytoskeleton with groups of vesicles around pail pore

Animal parasites

Usually have more than one host

Alveolata: Dinozoa

Cause the red tides

2 Right angle flagella

Bioluminescent

4 MEMBRANES ON CHLOROPLASTS

Protist Supergroup: Stramenopila

Diverse group

Strawlike hairs on surface of flagella for better movement

Stramenophila: Brown Algae

4 MEMBRANE CHLOROPLASTS

Marine only

Stramenophila: Diatoms

Silicate cell walls

Photosynthetic

Stramenophila: Pseudofungi

Eat by osmosis

Cause $7 billion in crop damages annually

Filamentous hyphae

Protist Supergroup: Rhizaria

Both flagellates and amoebae

Hair like pseudopodia

Broad diversity

Rhizaria: Radiolaria

Siliceous and star shaped

Rich fossil record

Rhizaria: Foraminifera

Calcium Carbonate

Marine

Rich fossil record

Protist Supergroup: Amoebozoa

Move and eat using pseudopodia

Free living

Slime molds

Protist Supergroup: Opisthokonta

Single posterior flagellum on swimming cells

Opisthokonta: Fungi

Caused amphibian extinctions

Opisthokonta: Choanoflagellates

Funnel-like food trapping collar around flagellum

Streptophytes

All land plants and some freshwater algae

Spindle microtubules

Flattened, upright branching

Streptophyte Synapomorphies

DNA

Cell structure

Biochemicals

Embryophytes

LAND PLANTS

1st colonization of land 450 MYA

Embryo stage early in the life of the sporophyte

Embryophyte Synapomorphies

Multicellular sporophyte

Resting embryo stage

Waxy cuticle

Multicellular reproductive structures

Apical meristems

Byrophyta

Gametophyte dominant

Small plants in moist habitats

Liverworts, mosses, and hornworts

Land Plant Phyla: Heptaophyta (liverworts)

Lack stomata

Single-celled rhizoids

4 valved capsule

Spores

Land Plant Phyla: Byrophyta (mosses)

Stomata

Multicellular rhizoids

Peristome teeth

Spores

Land Plant Phyla: Anthocerophyta (hornworts)

Horn shaped sporophyte

Meristem at sporophyte base

Spores

Tracheophytes

VASCULAR PLANTS

Sporophyte dominant

Water not always required to move sperm to egg

Tracheophyte Synapomorphies

Embryo as part of the seed

Roots, stems, and leaves

Xylem and phloem (vascular tissue)

Tracheid (transports water and mineral salts)

Less use of water for reproduction

What are the two seedless, vascular plants? And do they need water for fertilization?

Lycophytes and Pteridophytes. Water is required for fertilization.

Land Plant Phyla: Lycophytes (club and spike mosses)

Oldest extant vascular plant

Today, they are small herbs

Leaves are small with one vein

Land Plant Phyla: Pteridophytes (ferns)

Leaves mostly with circulate vernation

Large, deeply veined leaves

Stems range from subterranean to 20 meters

Spermophytes

SEED PLANTS

Dominant vascular plants

Why are seeds better than spores?

Better protection of the embryo

Provide nutrition for embryo

Dormancy mechanisms

Dispersal unit

Gymnosperms

Seeds are exposed at fertilization

Woody shurbs or trees

Gymnosperms make up what 3 phylum of land plants?

1. Cycadophyta (cycads)

2. Ginkgophyta (ginkgos)

3. Coniferophyta (conifers)

Land Plant Phyla: Cyacadophyta (cycads)

Palm-like shrubs

Large leaves with apical clusters

Cones attract beetles

Seeds attract vertebrates

Coralloid roots above ground

Mutualism with nitrogen fixing Nostoc cyanobacteria

Land Plant Phyla: Ginkgophyta (ginkgos)

Can live in the cold, heat, and polluted areas

Leaves bilobed and branches with short shoots

Land Plant Phyla: Coniferophyta (conifers)

All woody

Tolerate extreme cold

Conifer Ecological Adaptations

Conical (snow slides off without breaking)

Resin (protection from pathogens and animals)

Conifer Reproduction

Male cones are simple with pollen air sacs located low on the tree

Female cones are complex and located high on the tree

Seeds are winged with some bird dispersal

Land Plant Phyla: Anthophyta (angiosperms)

Fruit & Flowers

How did plants invade the land?

Gradually over time.

Until 1.2 BYA only cyanobacteria, then bryophytes were the first land plants.

What are the ecological effects of bryophytes?

Important in carbon sequestration.

Regulates carbon sink and buffers the climate

What are the ecological effects of ancient vascular plants?

Brought carbon out of the atmosphere and into the ground to form coal, lowering carbon levels and increasing oxygen levels

Large forests of lycophytes, pteridophytes and early seed plants.

What was the most critical innovation for land plants? Why?

The seed because:

1. Enclosed by maternal tissues that provide nutrients

2. Protection from: drought, UV light, and microbial attacks

What increased plant fitness and fostered diversification?

Leaves

Lycophytes have tiny, 1 veined leaves called _____.

Microphylls

Fern leaves evolved from _____.

Branched-stem systems

Pteridophytes and spermatophytes have _____ with highly branded veins.

Euphylls

Large, flat surface area on leaves improved ______.

Photosynthesis

What is the progression of euphylls?

1. Cylindrical, branched stem systems

2. 1 branch became dominant, central axis

2. Lateral branches shrank and flattened

4. Spaces between the lateral branches united

Microsporangia

Male gametophytes

Pollen grains

Megasporangia

Female gametophytes

Eggs

What are the ecological advantages of seeds?

1. Dormancy

2. Modifications aiding dispersal

3. Food/energy storage

When did angiosperms begin to be the dominant land plant?

Cretaceous

When did angiosperms arise?

190 MYA

Why are angiosperms so successful?

Complex vascular tissues

Fast life cycle

Fruit protects seeds

Efficent reproduction

What are the key synapomorphies of angiosperms?

Vessels

Flowers

Stigmatic germination

3n Endosperm

Fruit

What is the stamen?

Male sex organ of the flowers, made of an anther and a filament

What is the pistil?

Female sex organ of the flowers, made up of a stigma, style and ovary

What happens during double fertilization in angiosperms?

One sperm cell fuses with an egg cell to yield a diploid zygote

One sperm cell fuses with two polar nuclei to yield triploid endosperm

Angiosperm: Amborella trichopoda

No vessels

Dioecious

Angiosperm: Monocots

One cotyledon

Parallel veins

Reduction in parts

Scattered vascular bundles

Angiosperm: Eudicots

Tricolpate pollen

What do angiosperms used for fertilization?

Animals, wind and water

Characteristics of angiosperms that use wind for fertilization

Flowers reduced

Unisexual

No petals

Temperate climate

Early spring

Characteristics of angiosperms that use water for fertilization

Only in 11 families

Pollen is above, on, or below H2O surface

Pollen is filamentous

Characteristics of angiosperms that use bees for fertilization

Flowers often blue, purple, or yellow

Fragrant

Diurnal

Pollen or nectar rewards

Corolla is often bilateral

Characteristics of angiosperms that use bats for fertilization

White or pale green flowers

Musky odor

Nocturnal

Pollen or nectar rewards

Flowers are large and thick

Characteristics of angiosperms that use hummingbirds for fertilization

Red, yellow, or orange flowers

No odor

Diurnal

Nectar rewards

Corolla tubular, often pendant

What is a fruit? What is its purpose?

A ripened ovary that protects seeds and aids in dispersal.

How are seeds from fruit distributed?

Abiotic and biotic mechanisms:

gravity, wind, water, animals

What angiosperms have humans influenced?

Triticum aestivum: common wheat

Zea mays: corn

What are the importance of fungi?

Decomposer

Fermentation

Biochemicals

Food

Mycorrhizae

Medicine

What are the synapomorphies of Fungi and Animalia?

Heterotrophic

Absorptive nutrition

Food stored as glycogen

What are the differences of Fungi and Animalia?

Fungal body structure

Growth

Reproduction

What is the mycelium?

The vegetative part of fungus

What is the hyphae?

The fine branched filaments that make up the mycelium of fungi

Describe the fruiting body form of fungi.

Densely packed hyphae that have undergone sexual mating process

How do fungi reproduce?

Both sexually and asexually

What are the benefits of asexual reproduction in fungi?

No need to find compatible mate

Conidia

Asexual spores at the tips of specialized hyphae

What can rapid spread of fungi cause?

Food spoilage, allergies, and diseases

Is the life cycle of fungi haploid or diploid dominant?

Haploid