Page 26 - The Miracle In The Seed

THE MIRACLE IN THE SEED

Plant with 2n
Anther chromosome
constitution

Seedling

Mother cells
developing
Ovule in into
the ovary microspores in
the pollen sac Seed casing
Seed
The ovule develops Embryo (2n)
into a megaspore by Endosperm (3n)
meiotic division of
the mother cell
Meiosis Meiosis Double Fertilization
As a result of meiotic After pollination, a pollen
division, four haploid tube forms up to the ovary.
(n) microspores are In the tube are two
formed in each sperms, one of which is
pollen grain vegetative and the other
DIPLOID PHASE generative.
HAPLOID Meiosis
PHASE
Mitosis

Male
Pollen grains gametophyte
disperse
Three of the Pollen tube
four cells Sperm (n)
formed by
meiotic divi- Sperm (n)
sion degener-
ate, while the
remaining
one (the
megaspore)
goes through When the pollen
3 mitoses, re- tube reaches the
sulting in an Antipodals ovule, one of the
embryo sac sperms fertilizes
with 8 Cells forming the the egg and
nuclei. endosperm (polar forms an embryo
nuclei) while the other
fertilizes the
Synergids polar nuclei and
forms the en-
Egg (n) dosperm.
Vertical section of
the ovule

This diagram shows the phases from the flowering of a plant to seed formation. Any intelli-
gent person can see that such a process cannot be the result of coincidence. (Ozet Arpaci,
Biyoloji 3 (Biology 3), p. 17.)