Formation Of The Embryo Sac Flashcards
Is the megaspore mother cell diploid or haploid?
Diploid
Does the megaspore divide by mitosis or meiosis?
Meiosis
What does the meiotic division of the megaspore mother cell form?
Four haploid cells
What happens to three of the four haploid cells formed by the meiotic division of the megaspore mother cells?
They die off
What happens to the one remaining haploid cell formed by the meiotic division of the megaspore mother cell?
It is now called the embryo sac or megaspore
What is another name for the embryo sac?
Megaspore
What is the megaspore?
2
The embryo sac
The one remaining haploid cell formed by the meiotic division of the megaspore mother cell
What happens to the megaspore/embryo sac?
3
The haploid nucleus of the embryo sac divides by mitosis three times to form eight haploid nuclei
These nuclei are contained in the embryo sac
The embryo sac swells using food supplied by the nucellus
How many haploid nuclei doe the megaspore/embryo sac form by mitotic division?
Eight
What is the function of the nucellus?
It supplies food to the embryo sac which allows it to swell
What happens to each of the eight haploid nuclei formed by the mitotic division of the megaspore/embryo sac?
(4)
Five take no further part in regeneration and degenerate
Remaining three form the female gametes
Two of the gametes form the polar nuclei in the embryo sac
The remaining gamete forms a thin cell wall and becomes the egg cell
What happens to two of the female gametes?
They form the polar nuclei in the embryo sac
What happens to one of the female gametes?
It forms a thin cell wall and becomes the egg cell
What will appear by the time the embryo sac is mature?
The carpel will appear
