BIOL 111 Algae and Seedless Plants

Shared charactersitics of green algae and land plants

cell wall made of cellulose, store sugars as starch, same pigments for photosynthesis (chlorophyll a and b)

Charophytes

Green algae, chlorophyll a and b, cellulose cell wall, starch, closest relative to land plants

Sporophyte

multicellular diploid individual (2n)

sporangium

location of spore formation and meiosis

gametophyte

multicellular haploid individual (n)

antheridida

location of sperm production

archegonia

location of egg production

Spirogyro

filamentous, colonial green algae, chloroplast in long ribbon shape

Charophytes — spirogyra

Asexual reproduction of spirogyro

when conditinos are good: cell are haploid (n), they fragment and divide by mitosis so filaments can elongate

Sexual reproduction of spirogyro

when conditions are bad: conjugation, cell (haploid n) from different mating strains (m/f) come together to form diploid 2n zygotes, called zygospores

What happens after conjugation tubes form in sexual reproduction of spirogyra?

the cell contents condense (each cell is haploid n) and a cell from one filament moves through tube and fuses with the other cell through the conjugation tube

What happens after the contents condense in sexual reproduction of spirogyra cells?

Zygospore is formed (zygote, 2n), has a thick outer coat to survive poor conditions, zygospore will undergo meiosis to form haploid n cells

Chara

charophyte, multicellular algae, have gametangia (multicellular structures that produce gametes), have sterile jacket around gametangia that protects gametes from drying out (helped plants transition from water to land)

Chara

What structure is labeled A?

Archegonium, produces eggs

What structure is labeled B?

Branch

What structure is labeled C?

Antheridium, produces sperm

Gametophyte dominant

their main form is haploid, the dominate generation is n

Chara life cycle

f/m gametes n —fertilization—> zygote 2n —meiosis—> spore n —mitosis—> adult n —mitosis—> f/m gametes n

land plants

all multicellular, terrestrial (live on land), the zygote and embryo are protect inside parent tissue, primary producers in m ost terrestrial ecosystems

Land plant challenge: preventing desiccation (drying out)

adaption: wavy, waterproof covering

Land plant challenge: support for body

adaption: fibrous cells for support

Land plant challenge: getting resources for growth

adaption: division of plant into roots, shoots, and vascular tissue

Land plant challenge: gas exchange (O2 and CO2)

adaption: pores in leaves

Land plant challenge: fertilization and protection

adaption: gametangia and pollen

Alteration of generations

Have a multicellular diploid part of life cycle AND a multicellular haploid part of life cycle

Sporophyte

multicellular diploid 2n phase

Gametophyte

multicellular haploid n phase

Gametophytes produce ___

gametangia

Sporophytes produce ___

sporangia

Sporangia produces ____

spores by meiosis

Alternation of genrations life cycle

fertilization (gametes, egg/sperm, n) —> zygote 2n —mitosis—> sporophyte 2n —meiosis—> spore n —mitosis—> gametophyte n —mitosis—> gametes

Non-vascular land planrs

lack vascular tissue, no internal tissue to transport water and nutrients, places a constraint on how tall they can grow, mosses (part of larger group called bryophytes)

Dominant stage of moss

gametophyte (n)

Moss archegonium (egg)

Moss antheridium (sperm)

Moss reproduction

Capsule

holds the sporangium and the sporangium holds the spores

Seedless nonvascular plant cycle

sperm/egg —fertilization—> zygote 2n —> sporophyte 2n —> sporophyte attached to gametophyte 2n —meiosis —> sporangium produces spores n —> spores develop into multicellular gametophyte n —> archegonium/antheridium

moss antheridium, male reproductive organ, produces sperm, haploid

moss archegonium, female reproductive organ, produces eggs, haploid

Sporangium vs sporophyte

sporangium is the sac that contain/produces spores, the sporophyte is the diploid generation of a plant

Vascular land plants

sporophyte 2n stage is dominant, vascular tissue (tissue to transport water and nutrients, allows plants to grow tall)

Fern dominant phase

Sporophyte 2n

fern gametophyte n, sporophyte grows off gametophyte

sorus (cluster of sporangia)

Name structures A-C

Sorus, sporangium, spores