Bio Ch 18

describe the similarities and differences between green algae and land plants

• Algae does not protect their embryos 

• Plants evolved from a form of freshwater algae 

• Both in supergroup archaeplastids 

  • Have chlorophyll a and b + pigments 

  • Store excess carbs as starch 

  • Cellulose in cell walls

What are the 5 significant events in evolution of land plants and the accompanying type of plant

• embryo protection - all plants, algae do not

• Vascular tissue - lycophytes

• Megaphylls - ferns

• Seeds - gymnosperms

• Flowers - angiosperms

What are lycophytes?

the first land plants to have vascular tissue

• ancient, seedless

What are megaphylls?

complex leaves, also called fronds

What is the evolutionary significance of embryo protection?

• Mosses lack vascular tissue but protect their embryos 

• Higher survival bc allows it to survive dry conditions

What is the evolutionary significance of vascular tissue?

transports water; true roots, stems, leaves 

What are the very narrow leaves of lycophytes?

Microphylls

What is the evolutionary significance of megaphylls

Increases amount of photosynthesis and carbs produced

What is the evolutionary significance of seeds

• Embryo + organic nutrients in a protective coat 

• dormancy/survival until favorable conditions

What is the evolutionary significance of flowers

• Reproductive structure to attract pollinators and create fruits

• More pollinated than others

In the alternation of generations, plants exist in what two forms?

Sporophyte 2n & gametophyte n

Sporophyte produces _____ cells by _____

haploid meiosis

gametophyte produces _____ by _____

gametes mitosis

gametes fuse to form _____

sporophyte

As plants evolved, _____ got smaller

gametophytes

Dominant generation in nonvascular plants is

gametophyte

Dominant gen in vascular plants is

sporophyte

The trend towards sporophyte dominance is an adaption to what and why?

life on land bc diploid is tougher than haploid

What are nonvascular plants?

Bryophytes

characterize and give examples of nonvascular plants

• receive nutrients and water via osmosis and diffusion into itself

  • Ex: mosses, liverworts, hornworts 

  • Often pioneer species in bare habitats + help retain moisture and prevent erosion

what differentiates vascular from nonvascular plants

internal transport system; sporophyte dominance

• Allows plant to live in dryer conditions and grow taller (maximize photosynthesis) 

characterize and give examples of seedless vascular plants

Have vascular tissue, true roots, stems, and leaves

• First plants to grow taller and live farther from water sources

• Ex: Ferns (e.g., bracken fern), Horsetails (Equisetum), Club mosses

characterize and give examples of gymnosperms

• Seeds are not enclosed in fruit (“naked seeds”)

• Produce pollen and cones

• Usually woody and long-lived

• Dominant plants in many cold or dry environments

• Ex. Conifers (pine, spruce, fir), Cycads, Ginkgo (Ginkgo biloba)

characterize and give examples of angiosperms and their reproduction

• Vascular plants with flowers

• Seeds are enclosed within a fruit

• Undergo double fertilization

  • One sperm forms the zygote 2n

  • Other sperm forms endosperm 3n (stored food)

• Most diverse and widespread plant group

• Highly specialized for pollination and seed dispersal

what’s the female gametophye of an angiosperm?

embryo sac

What’s the male gametophyte of an angiosperm?

pollen

What does gymnosperm mean?

naked-seed plant

Describe the life cycle and reproductive strategy of nonvascular plants

• Gametophyte = dominant gen = green “leafy” part

  • Gametophyte stage is dependent on water for reproduction bc flagellated sperm swims to female

life cycle = alternation of gens

Describe the life cycle and reproductive strategy of seedless vascular plants

• Do not produce seeds; reproduce via spores

• Independent gametophyte

• Still require water for fertilization

Describe the life cycle and reproductive strategy of gymnosperms

• Do not require water for fertilization; microscopic + dependent gametes

• Male gametophyte = pollen grain

• Female gametophyte develops inside the ovule

What are the major subgroups of angiosperms?

monocots and eudicots

charac. monocots

• Parallel leaf veins

• Flower parts in multiples of three

• Scattered vascular bundles

• Ex. Grasses (corn, wheat), Lilies, Palms

charac. eudicots

• Branched leaf veins

• Flower parts in multiples of four or five

• Vascular bundles arranged in a ring

• Ex. Roses, Oaks, Beans, Sunflowers

what makes starch in an algal cell?

pyrenoid

summarize economic significance of plants

food; products made from plants; pharmaceutical purposes

summarize the ecological significance of plants

oxygen production; can clean up toxic substances; forests are key in water + carbon cycles; prevent runoff

what are the hyphae of a fungus and its function

thin filaments of cells

• Make up a fungus; pack tg to make mushroom

• Give mycelium a large surface area for absorption 

• Extends towards food growing from tips, where nutrients are sent

Define the mycelia

mass of hyphae; main body of fungus

fungal cells have thick walls of

chitin

what divides cells of hypha

wall/septa

• pores allow cytoplasm to cross

Fungi and animals are both (2)

• Opisthokonts

• chemoheterotrophs

What makes fungi unique?

• Animals ingest food, fungi grow into it 

• Animals are motile, fungi + plants are not 

• Fungi reproduce via spores 

• Has mycelium body while plants + animals have tissues/organs 

• Haploid (like plants sometimes) 

• spores/mating hyphae to reproduce (plants use spores some) 

summarize the life cycle of a fungus

A fungus typically lives most of its life as a haploid mycelium, reproducing by spores, with a brief diploid stage occurring only during sexual reproduction before meiosis restores the haploid condition.

• haploid stage dominates

• No alternation of generations

_____ acquire nutrients and moisture, photosynthetic partner makes food

lichens

____ ____ form mutualistic relationships with roots of most plants

mycorrhizal fungi

describe the economic and ecological significance of fungi

• lichen; mycorrhizal fungi

• Produce medicines (penicillin); Yeast makes food; mushrooms are eaten

• Saprotrophs, so they decompose 

• Some eat animals for nitrogen (nitrogen cycle) 

provide examples of fungal diseases

• Ergot fungus grows on grains, causes hysteria/convulsions

• Rice blast disease kills ⅓ of rice 

• Candida albicans -> “yeast” infections, thrush, 

• Tinea -> ringworm, athlete’s food

• White nose syndrome killed bats

what makes up plant vascular tissue?

xylem + phloem

what is the placenta of plants

endosperm

What is a spore?

A reproductive cell that develops into new organism w/out having to fuse with another reproductive cell

mushroom/puffball are only temporary reproductive structures made of ____ ____

dikaryotic hyphae

What are sporangia?

sacs or receptacles that produce and store reproductive spores