Bio 2 Plants Exam

Red Algae

• Cellulose Cell Wall

• Chlorophyll A pigment

• Phycoerythrin pigments for green and blue light

Streptophyta

• Phragmoplasts and Plasmodesmata

• Oogamy

• Apical Growth

Phragmoplasts

A complex structure that serves as a scaffold for cell plate assembly

Plasmodesmata

Channels that penetrate the cell walls of adjacent cells

Parenchyma

the basic tissue type in the streptophytes with cells linked by plasmodesmata

Oogamy

Gametes are egg and sperm which differ greatly in size and movement

Chara (Stonewort)

• Has apical growth

• Life cycle of mostly haploid but four offspring after fertilization and mitosis

Cuticle

a waxy coating that slows water los

Sporopollenin

Prevents dessication in spores

Stomata

closable openings that regulate gas exchange (most lineages)

Pigments

protect against UV radiation

mycorrhizae

A mutually beneficial association with fungi that promotes nutrient uptake from the soil

Bryophyta

Nonvascular land plants with conspicuous haploid and diploid life stages, swimming sperm, and no true organs. Sporophyte dependant on gametophyte.

Hornworts

• Cells contain one chloroplast

• Sporophyte from meristem

• Permenently open stomata

Mosses

• Dead hydroid cells which leave a channel for water to move

• Peristome teeth aid dispersal hydroscopically

Liverworts

• No true stomata

• Growth occurs at growing points at apex of the plant

• Gemmae cups

Tracheophyta

Have tracheids and branched independent sporophytes at maturity

Lycophyta

• Mostly homosporous

• Have microphylls

• Dichotomous branding sporangia called strobili

• Dicotomous branching roots

Euphyllophyta

• Have true leaves

• Contain megaphylls

• All vascular plants that arent lycophytes

• Have multiflagellate sperm

• Endogenous branching roots

Vessel Element

Special xylem in flowering plants that has loss of end cell walks to make water transportation more efficient

Spermatophyta

• Vegetative: Seconardy Growth

• Heterospory with seeds and pollen

Vascular Cambium

Produces secondary xylem (wood) and secondary phloem (inner bark) in seed plants

Cork Cambium

Produces the waxy-walled protective cells that become the outer bark

Gymnosperms

• Woody, lacking the protective ovary outside seeds

• No flowers or fruits

• Produce softwood

• Have only tracheids as water conductors

Cycadophyta

• Short woody trunks

• Leaves similar to palms

• Dioecious cones

• Sperm with flagella

Ginkgophyta

• Has one relict species

• Sperm with flagella (motile)

• Dioecious

Gnetophyta

• Has the three families Welwitschiaceae, Ephedracae, and Gnetaceae

• Was once thought to be sister to angiosperms

Coniferophyta

• Well-branched trees with simple leaves like needles or scales, reduced megaphylls

• NO flagellated sperm

• Cones as reproductive structures

• Wind pollinated and seed dispersal by animals

Angiosperms

• Seed Plants with reproductive organs in flowers and seeds enclosed in fruits

• Vessel Elements in xylem

• Net Venation in leabes

• Double fertilization

Cotyledons

Seed leaves that can digest the endosperm and enlarge when the seed germinates

Berry

Single carpel or multiple fused carpels

Aggregate Fruit

Multiple pistils and carpels fused or unfused

Multiple Fruit

Fused mass of many individual flowers

Photorespiration

Rubisco using O2 as substrate instead of CO2 which oxidizes carbon instead of fixing. Happens a lot in hot environments

C4

Type of photosynthesis used by plants in hot and sunny but wet conditions. Has Kranz anatomy which isolates Rubisco to the bundle sheath

CAM

Type of photosynthesis used by plants in hot, sunny, and dry conditions. Stomata open at night to fix carbon which is metabolizes during the day.

Mycoheterotrophs

Three way association where a plant attaches to the mycorrhizal fungi of another plant

Constitutive Defences

Defences always present in a plant. Mostly mechanical.

Induced Defences

Defences produced in reaction to a pathogen, herbivore, or threat

Laticifers

Produce latex to gum up insect mouths or poison them

Alkaloids

Secondary metabolites that contain nitrogen and include stimulants and narcotics (toxins)

Avr (avirulence) genes

Genes that code for elicitors (Avr) proteins

Elicitors

Distinctive molecules in pathogens that trigger plant defenses

R (resistance) genes

plant genes recognize elicitors via “lock and key” mechanism and confer resistance to specific pathogens

Phytoalexins

antibiotics toxic to bacteria and fungi

Pathogenesis-related (PR) proteins

enzymes that break down cell walls of pathogens

Jasmonate pathway

results in the production of proteins that reduce the growth of insects by inhibiting their digestion

Auxin

controls the direction and arrangement of apical growth, gravitopism, phototropism, and apical dominance

Ethylene gas

Gaseous compound controls fruit ripening, leaf drop, germination, and the development of apical hook

Apical Dominance

Terminal bud produces auxin, prevents lateral buds from growing

Ethylene gas

promotes leaf abscission and senescence; speeds ripening of fruit, reduces growth, affects phototropism, promotes seed germination in some species

Climacteric

Fruit that continues to ripen even after harvest