Theme 2 Classification Of Land Plants Gymnosperm/angiosperm Flashcards
What are the characteristic of gymnosperms in relation to the ovule
Sporophyte gymnosperm structure make a female gametophyte with egg
the egg is connected to the sporophyte with protective tissues, once fertilized it becomes the seed
The seed is the embryo which desiccates and is dispersed
Were embryos in mosses and ferns protected?
No
They were retained on female gametophyte, but not protected
In gymnosperms, what is the male gametophyte?
The pollen, this time spores are not released, the pollen is
What is the megaspore and microspore in gymnosperms
The megaspore is the thing that makes the female gametophyte inside the ovule
The microspore is the thing that makes the male gametophyte (pollen)
What is pollen?
Haploid multicellular
Holds sperm
What is the gymnosperms life cycle
Female megasporocyte(2n) inside ovule turn into four megaspores (haploid) through meiosis. one survives
Through mitosis, the surviving megospores turn into female gametophyte which holds up to four archegonium (n).
The four archegonium hold one egg cell (haploid) each (total four egg cells) these are fertilized by the pollen tube which had two sperms from the microsporangium but one died off, and make four embryos. The four embryos splits into four through mitosios, making total 16 embryo.
In end only one survives.
Rest of gymnosperms for other cards
Ok
What is different in angiosperms from gymnosperms
In gymnosperms the sperm split in two and one dieed off
In angiosperms, the second sperm is retained and one make embryo the other make endosperm (storage unit for plants)
The ovary (fruit) protects the ovule (seed)
Hermaphrodites (have ovary and anther)
What is the double fertilization in angiosperms
One sperm fertilizes the egg cell
And the other sperm fertilizes the diploid central cell and develops into the endosperm (Triploid, filled with starch is the nutritive tissue left behind)
Where does the pollen in angiosperms develop
In the anther
Life cycle of angiosperms
Anther on sporophyte has 2-4 sporangia which undergo meiosis to make haploid spores. Then they turn into pollen. The pollen rupture the anther when mature and dispersed
Pollen germinates, goes through stigma then into the style. The pollen tube get two sperm cells antlers the ovary.
Throguh meiosis the female gametophyte has eight nuclei and seven cells (one central diploid cell)
The tube finds the ovule through chemo taxis, and one sperm cell fuses with femal haploid egg cell and makes zygote
The other sperm fuses with the diploid central cell of the female gametophyte and make triploid cell called endosperm.
The zygote turn into an embryo and the embryo stem is hyocotyl and the the leaves are dicot
The embryo becomes a seed and the ovary becomes fruit.
What are monocots, give examples
Single cotyledons (embryonic leaves)
Veins on leaves run parallel (straight)
Grasses palms Lillie’s orchids
Petals in threes
What are eudicots (dicot), give examples
2 cotyledons
Reticulate veins (branching)
Fruit trees roses beans potatoes
Petals in fours or fives
What does the angiosperms seed consist of
Seed coat (2n)
Endosperm (3n)
Embryo (2n)
Female gametophyte tissue (n)
What do gymnosperms have in relation to the xylem
Angiosperms?
Tracheids
Trachieds and vessels
