(i) The production and development of seedless fruit is called parthenocarpy.
(ii) Fruit like structures may develop from the ovary without the act of fertilization. Such fruits are called parthenocarpic fruits
Examples: Seedless-Banana, Grapes, Papaya
(i) Parthenocarpy is of three types
1) Genetic Parthenocarpy
(i) Arises due to hybridization or mutation. 
2) Environmental Parthenocarpy
Environmental conditions like frost, fog, low or high temperature induce Parthenocarpy.
Example - low temperature for 3-19 hours induces parthenocarpy in Pear.
3) Chemically induced Parthenocarpy
(i) By the application of growth promoting hormones like auxins and gibberellins.
Significance:
(i) Seedless fruits - Significance in Horticulture have commercial value useful for the preparation of jarns, jellies, sauces, fruit drinks,
(ii) High proportion of edible part is available

(i) The primary endosperm nucleus divides immediately after fertilization and develops into an endosperm.
(ii) It is a nutritive tissue, and regulatory structure by undergoing repeated mitosis to form triploid (3n) endosperm that nourishes the developing embryo. Depending upon the mode of development three types of endosperm are recognized.
1) Nuclear endosperm:
(i) Primary endosperm, (PEN) nucleus undergoes several mitotic divisions. There is no cell wall formation So free nuclear condition exists in the endosperm.
Example:
Coccinia, Capsella, Arachis
2) Cellular endosperm:
(i) Primary endosperm nucleus divides into two nuclei There is cell wall formation.
(ii) Subsequent division also follows cell wall formation. It is said to be cellular endosperm
Example:
Adoxa, Helianthus, Scoparia.
3) Helobial endosperm:
(i) Primary Endosperm Nucleus moves towards the base of embryo sac.
(ii) Divides into two nuclei cell wall formation occurs forming a large micropylar chamber and a small chalazal chamber.
(iii) The nucleus of micropylar chamber further undergoes several free nuclear divisions. The nucleus of the chalazal chamber may or may not divide.
Example:
Hydrilla, Vallisneria.

The fusion of male and female gamete is called fertilization. Fertilization in angiosperms is double fertilization type.
Pollen germinates on the stigma. Pollen tube produced grows through the style towards the micropyle of the ovule pollen tubes enter into one of the synergids of the embryo sac.
Discharge of male gametes occur syngamy - one gamete and an egg cell fuses to form diploid zygote Triple fusion - The other male gamete fuses with the two haploid female polar nuclei. A triploid primary endosperm nucleus results.

(i) A mature ovule (megasporangium) consist of a stalk and a body
(ii) Funicle - The stalk of the ovule by which it attaches the ovule to the placenta.
(iii) Integuments - one or two protective covering around the nucellus
(iv) Micropyle - Pore present at the tip of the ovule where the integument is absent
(v) Chalaza - The basal region of the body of the ovule where the nucellus, the integument and funicle meet or merge
(vi) Embryosac- The female gametophyte oval sac like structure in the nucellus, toward the micropylar end.