lab 6 Flashcards
what is the defining feature of the spermatophyte lineage?
The seed!
what does a seed grow into? sporophyte or gametophyte?
sporophyte
do gymnosperms and angiosperms have the same seeds?
same function, but different structures
how do spermatophytes differ from their closest relatives?
they retain their spores within the diploid sporophyte parent –> germinates into gametophyte
who can do heterospory?
just spermatophytes
what do microspores develop into?
pollen grains
megastrobili
female ovulate cones
microstrobili
male cones
-aggregation of many small structures that encase the pollen in microsporangia
gymnosperms and angiosperms: flowers/fruits or cones?
gymnosperms = cones angiosperms = fruit/flowers
where do angiosperm seeds live?
mature ovule with nutritous tissue
where do gymnosperm seeds live?
they be livin in a pine cone
are spermatophytes sporophyte or gametophyte dominant?
spotophyte (same as lycophytes and monilophytes)
which evolved first, gymnosperm or angiosperm?
gymnosperm
why called “gymnosperms”
gymno = naked
- no ovule to protect seeds
- gametophyte develops on outside of sporophyte on cones
how and why do gymnosperms arrange their strobili?
microstrobili are lower and megastrobili are higher to discourage self fertilization
microstrobili has microsporophylls which have recepticles called microsporangia which have microsporocytes which divide thru meiosis into microspores which develop into male gametophytes called pollen grains
megastrobili have megasporophylls which have ovules which each have 1 megasporangium which have megasporocytes which divide thru meiosis into megaspores, one of which becomes the megagametophyte
describe gymnosperm fertilization
pollen grain go to ovuliferous scales of megastrobilus and then form pollen tube for male gametophyte travel to. gets to female gametophyte through hole in ovule called micropile. male gametophyte releases 2 sperm, one of wich fuses with egg to form zygote
which are more diverse: angiosperm or gymnosperm?
angiosperm
why called “angiosperm”
angio = vessel/enclosure
-embryo lives in ovary = sporophyte tissue that supports it as it develops into seed
what are fruit
mature ovary that carries germinated seeds
why flowers?
- house male and female reproductive structures
- bright colors attract pollinators
2 types of angiosperms
monocots and dicots
double fertilization
- female gamete joins with 2 male gametes to form endosperm which stores nutrients for developing plant embryo
- only in angiosperm
how are flowers attached to petal stem
by a peduncle surrounded by whorls of sepals (calyx)
whats so special about sepals?
they’re usually photosynthetic
perianth
calyx of sepals + corolla or petals
androceium
-in flowers
made up of stamen (male reproductive units) made of anther (microsporangium) and filaments
gynosium
- in flowers –>
- made of female reproductive units called carpels made of
- sticky stigma where pollen is deposited
- thin style
- ovary containing 1+ ovules which develop into seeds during fertilization
special megagametophyte of angiosperms
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