Embryology, Fruits and Seeds Of Anthophyta Flashcards
Which type of plant has the most reduced gametophytes
Anthophyta
The mature micro gametophyte consists of only ___ or ___ nuclei
The mature mega gametophyte in most instances consists of only ____ cells
2
3
7
In anthophyta, both antheridia and archegonia are ____
Lacking
How is pollination in anthophyta
Indirect
Pollen grains are deposited in the stigma, after which the pollen tube conveys two non-motile spermatids nuclei to the female gametophyte.
After fertilization, the ovule which enclosed in the ovary, develops into a ___, while the ovary develops into the ___
Seed
Fruit
Each ovule within the ovary contains a ________ which undergoes meiosis, producing ____ large functional megaspore, and _____ small non functional spores that degenerate
Megaspore mother cell (mega sporocyte)
1
3
The large megaspore undergoes ____ successive mitotic divisions that yield ___ nuclei. These nuclei are separated by cell walls to form the _______, _____ structure called the embryo sac or mature female gametophyte
3
8
Eight-nucleate
Seven felled structure
The embryo sac contains what
Egg
Two synergid cells at the end of the gametophyte closest to the micropyle
At the opposite end of the embryo sac are 3 antipodal cells, while in the large central cell are two polar nuclei.
The mature male gametophyte is produced after the ______ has been transferred to the stigma
Pollen grain (pollination)
One of the pollen cells, the ______ cell generates a pollen ____ which grows down the ____ and into the ovary. The other cell: ______ cell divides to form two Sperm nuclei. These Speke nuclei migrate down the pollen tube into the _____
Tube
Tube
Style
Generative
Embryo sac
What is unique about anthophyta sexual reproduction cycle that is not seen anywhere else
The two sperm nuclei enter the embryo sac, both of them participate in fertilization. One spent nucleus fuses with the egg, forming the zygote that develops into the embryo within the seed. The second sperm nucleus fuses with the two haploid polar nuclei, forming a Triploid (3n) nucleus that develops into endosperm in the seed. This process is called double fertilization!
What processes are initiated by double fertilization
-the endosperm nucleus divides to form endosperm
-zygote develops into an embryo
-the integument (outer coverings of the ovule) develop into the seed coat
-ovary wall develops into the fruit.
This the ovule develops into the seed
After fertilization had occurred, the diploid zygote divides ______
Mitotically
The first divisions of the zygote yield what cells and how do they divide
Terminal cell- divides longitudinally
Basal cell- divides transversely
The first 2 divisions result in a ___ celled _____
4
Proembryo
What develops from the lower cells in the proembryo? What type of divisors occurs
Suspensor
Series of transverse cell divisions
Each of the cells of the embryo divides into an outer ______ and an inner ______
Dermatogen cell
Cell
Now the young embryo consists of external dermatogen cells and 8 internal cells from which the ground meristem and procambial cells will originate
During the embryo development the last cell in the suspensor enlarges to form the ______.
The suspensor cell on which the embryo rests is known as the _____
Basal cell
Hypophysis
Through a series of cells divisions, the hypophysis will form _____ cells.
The tier closest to the suspensor will form the _______ while the tier closest to the embryo will differentiator into the ____
8 (2 tiers of 4 cells)
Root cap
Radicle
At a later stage, the embryo will have grown larger and more or less ________ shaped. The two lobes of the embryo are each destined to develop into _____
Heart
One of the two cotyledons
In the heart shaped stage, the endosperm has become _____
Cellular
As the cotyledons of the embryo differentiate, they store a large amount of food which has been obtained by ________
Digesting and absorbing the endosperm tissue
A section through a maturing ovule will reveal an embryo consisting of
-2 large cotyledons with a small epicotyl between them and attached to a large basal axis (the hypocotyl).
-most of all the endoderm has been absorbed by the cotyledons
-the integuments of the the ovule have grown and hardened into the seed coat.
-basal portions of the embryo is termed the radicle
Do endosperm tissues always get absorbed by the developing cotyledons?
No, In corn and wheat, they have a large endosperm retained. This is utilized during germination and not during embryo development
