Question

What is the life cycle of gymnosperms (pines)? I'm a little confused.

Answer 1

this is what I have so far,

a) Pollen cone contains microsporangia that contains microsporocyte (2N)
b) Microsporocyte undergoes meiosis producing haploid microspores (N)
c) Microspore develops into the male gametophyte (pollen grain).
d) 2 pollen grain cells die
- one cell (sperm cell) devides to produce sperm cell and sterile cell
- other cell divides to make pollen tube cell
e) megasporocyte(2N) undergoes meiosis to produce 4 haploid cells
- one survives as megaspore (N)
- surviving megaspore develops into gametophyte by mitosis.

Answer 2

im not sure about part D though

Answer 3

ok and this is the rest, is this cycle now right?

• surviving megaspore develops into female gametophyte by mitosis. Contains archegonia, each archgonia develops into an egg.
• Pollen gets to the female gametophyte by wind.
• Fertilization occurs when sperm and egg fuse, makes zygote.(2n) endosperm is haploid (n).
• One zygote develops into an embryo. Ovule becomes a seed, food supply, and seed coat.
• Seed falls when cones mature, and fall to make new pine tree.