Chapter 26 and 32 vascular seed plants

Seed plants synapomorphies

Sporophyte is dominant. vascular tissue. true leaves stems and roots. true heterospory. sporopellenin

Novel traits

Gametophyte is reduced to microscopic structure inside plant. pollen is created so that reproduction is not dependent on water. seeds are created for the same reason

Female gametophyte

Only a few microscopic cells. when egg is fertilized it will create a zygote that will grow into a sporophyte individual when it germinates. embryo is nutritive tissue and seed coat.

male gametophyte

called pollen. dispersed by wind water or animals when pollen reaches female gametophyte it will develop a pollen tube towards the egg. it then produces sperm that travels down towards the egg.

phylogeny

Divided into Gymnosperms (naked seed) and Angiosperm(seed in vessel)

Gymnosperm traits

seed sheltered in woody leaves called sporophylls. gametes are on separate on different cones but on same plant. can be monoecious or dioecious. pollinated by wind. tracheids transports water/minerals(xylum). adapted to live without water.

Conifers

dominant gymnosperms. leaf is needle shape. for cold dry weather. high altitudes. tree is sporophyte and monoecious

cycads

dominant in prehistoric time. mistaken for palms. live in mild climates

gingkophytes

only one species. gingko biloboa. fan leaf

gnetophytes

live in arid regions. unresolved phylogeny.

Conifer male cones

have microsporangia. have microsporocytes(diploid) in microsporangia which produce microspores through meiosis. microspores mitose to create pollen surrounded by sporopollenin.

Conifer pollen

comprised of generative cell and pollen tube cell. generative cell produces 2 haploid sperm cells via mitosis. pollen tube cell creates pollen tube.

Conifer female cones

have megasporangia which create diploid megasporocytes which create 4 megaspores (haploid) via meiosis. only one survives to become the gametophyte 

Conifer fertilization

a pollen lands at the base of female scale. pollen tube cell then germinates to create the tube towards the gametophyte. generative produces sperm(n) with mitosis. resulting diploid embryo will divide via mitosis to become sporophyte. becomes seed with seed coat, nutritive tissue and embryo tissue

conifer reproduction

Angiosperms

Dominant terrestrial group. have flowers and fruits. monoecious and dioecious. pollination via wind, insects, mammals. vessel cells in xylem tissue

Flowers

modififed leaves around central receptacle. sepals, petals, carpels and stamen. petals attract pollinators. 

Carpel

Gynoecium. female flower. stigma ovary and style.

Stamen

Androecium. male flower. anther filament

Monoecious flower

perfect flowers. have both carpel and stamen

dioecious flower

imperfect. only have stamen or carpel

style

Stigma

ovary

anther

Filament

receptacle

sepal

Gynoecium

produces eggs. called carpel or pistil. can have multiple. contains oneor more ovules. (megasporangia). stigma is where pollen is deposited. style grows pollen tube

Androecium

stamen. produces pollen. filament and anther. filament supports anther. anther is a sac like structure that has microsporangia 

pollen production/ male gametophyte

microsporangia(diploid) produce microsporocytes(diploid) that make microspores through meiosis(haploid)

female gametophyte

megasporangia (2n) is in ovule. makes megasporocyte (2n) which makes 4 megaspores via meiosis(n). only 1 survives to become gametophyte. then divides 3 times via mitosis to produce 8 nuclei sent across 7 cells

Antipodals

polar nuclei

synergids

egg vacucole

Fertilization