Notes

Sexual Reproduction in Flowering Plants:- @EduChacha
A) Androecium:- www.educhacha.in
1) Male reproductive organ
2) Stamen- made up of anther and filament
B) Microsporangium:-
1) present in the anther and develops into a pollen sac
C) Tapetum:-
1) The innermost layer of microsporangia having multinucleate cells
2) provide nourishment to pollen grains
D) Sporogenous tissue:-
1) microspore mother cell
2) homogeneous tissue present in the microsporangia of young anther
3) each cell is capable of developing into microspore mother cell
E) Microsporogenesis:-
1) formation of each microspore from microspore mother cell ( PMC) by meiosis
2) microspores develop into pollen grains
F) Exine:-
1) outer layer of pollen grains
2) made up of sporollpollenin, the most resistant organic compound known
>>>>>> Germpore do not contain sporopollenin
G) Intine:-
1) inner layer of pollen grains
2) made up of cellulose and pectin
H) Vegetative cell:-
1) large cell of pollen grains with ample food reserve
2) has irregular nucleus
I) Generative Cell:-
1) smaller spindle-shaped cell of pollen grains
2) divides mitotically forming two male gametes
J) Gynoecium:-
1) Pistil:- made up of stigma, style and ovary
>>>>> Syncarpous- pistils fused. E.g— Papaver
>>>>> Apocarpous- pistil free. E.g— Michelin
K) Megasporangium:-
1) ovule
2) present in the ovary, attached to placenta
>>>>> One ovule— wheat, mango, paddy
>>>>> Many ovules— watermelon, papaya, orchids
L) Funicle:-
The stalk by which an ovule is attached to the placenta
M) Hilum:-
The junction between funicle and ovule
N) Integuments:-
1) The double protective envelopes of the ovule
2) Encloses nucellus except at micropyle
O) Micropyle:- www.educhacha.in
1) a small opening in the integuments
2) pollen tube enters through this pore
P) Chalaza:-
1) The basal part of the ovule opposite to the micropyle end
2) Antipodal cells are present at the chalaza end
Q) Megasporogenesis:-
1) formation of megaspore from megaspore mother cell ( MMC) by meiosis
2) only one cell at the micropyle end differentiates into megaspore mother cells
R) Female gametophyte:-
1) embryo sac
2) only one of the four megaspore develop into female gametophyte,rest three degenerate

>>>>> Pollination:- transfer of pollen grains from anther to stigma
1) Autogamy:- self pollination within the same flower
>>>> cleistogamous:- flowers which do not open
E.g— Viola, Oxalis, Commelina * TRICK— VOx.Com
2) Geitnogamy:- transfer of pollen grains to the different flower of the same plant
3) Xenogamy:- transfer of pollen grains to the stigma of different plant

Pollinating agents:— 1) Insects or wind- water hyacinth, water lily
2) Water- Vallisnaria, Hydrilla, zoostera
3) wind- grasses
4) Moth- Yucca www.educhacha.in

Emasculation:— Removal of anther from bisexual flower to facilitate cross fertilization
Bagging:— covering of emasculated flower with a bag to prevent contamination of stigma by unwanted pollen

Double fertilization:—
Syngamy:— fusion of egg nucleus and make gamete to form zygote
Triple fusion:— formation of a triploid primary endosperm nucleus by fusion of the second male gamete and two polar nuclei
Endosperm:— Develops from primary endosperm cells
Triploid in nature
Coconut water and tender coconut (free nuclear endosperm)
Perisperm:— Residual nucellus in the seed E.g— black pepper and beet

False fruit— Fruits which do not develop from ovary, it develops from other than ovary
E.g— Apple and strawberry, thalamus is a part of the fruit
Parthenocarpy:— Development of fruit without fertilization
Can be induced by growth hormone application
Seedless fruits E.g— Banana
Apomixis— Asexual reproduction
Production of seed without fertilization
Embryo is formed without fertilization from diploid egg cell
E.g— Asteraceae, grasses
Polyembryony:— Nucellar develop into embryos
Formation of multiple embryos in a seed, all the plants are genetically identical
E.g— Mango and citrus