(i) The farmer was spraying auxins or gibberellins in low concentration which have been found to induce parthenocarpy in several plants, e.g. tomato, cucurbits, strawberry, fig, etc.
(ii) This is called chemicallyinduced parthenocarpy, which is not harmful for the consumers. However, pesticide sprays are harmful for our health.
(iii) In parthenocarpy, fruit formation occurs without fertilisation. It can be of three types, i.e. genetical, environmental and chemically induced (as done by the farmer).
(iv) Ram is an intelligent, observant, inquisitive boy who is concerned about the day-to-day activities that happen around him.

1.Embryo developed from the synergid is haploid as the ploidy level of the synergid is haploid. 
2.Embryo developed from the nucellus is diploid as the ploidy of the nucellus is diploid. 
3.Presence of more than one embryo in a seed is called polyembryony, e.g. lemon, groundnut, etc. 
4.Polyembryony plays an important role in plant breeding and horticulture. The plantlets obtained from these embryos are virus-free and have more vigour. Hybrid varieties of several food and vegetable crops are being extensively cultivated and these hybrid cultivars possess high productivity. 

Replacement of the normal sexual reproduction by asexual reproduction without fertilisation is called apomixis, e.g. replacement of the flower by bulbils and replacement of the seed by a plant. Apomictically produced offsprings are genetically identical to the parent plant. In flowering plants, apomixis is used in a restricted sense to mean angiosperm, i.e. asexual reproduction through seeds. In some plant species, it is common, e.g. Asteraceae and Poaceae. In some species, the diploid egg cell is formed without reduction division and develops into embryo without fertilisation. It is an asexual reproduction in the absence of pollinators such as in extreme environments.
In some species like Citrus, some of the nucellar cells surrounding the embryo sac start dividing and develop into embryo. It occurs in the megaspore mother cell and does not undergo meiosis, thus produces diploid embryo sac through mitotic divisions. Thus, it explains that, embryo sacs of some apomictic species appear normal but produce diploid cells.

1.As the name suggests; double fertilisation involves two types of fertilisation-syngamy and triple fusion. The release of two male gametes into the cytoplasm of one of the synergids causes its degeneration.
2.One male gamete fuses with the egg cell to form a diploid zygote (which later forms embryo). This process is called syngamy or generative fertilisation. The other male gamete fuses with the two polar nuclei in the central cell by a process called triple fusion, which results in the formation of a triploid. 
3.Primary Endosperm Nucleus (PEN) and the central cell becomes the Primary Endosperm Cell (PEe). This PEC divides repeatedly to form triploid endosperm tissue which further undergoes successive free nuclear divisions to give rise to free nuclear endosperm (free-nuclei).
4.This stage is followed by the wall formation around the cellular endosperm. Thus, the events of double fertilisation are immediately followed by post-fertilisation events involving development of endosperm.

(b) (i) Since the anthers of angiosperm flowers are bilobed with two thecae (sporangia) in each lobe, they are called dithecous.
(ii) The plants grown from the hybrid seeds show segregation of traits and do not maintain the hybrid characters; so hybrid seeds have to be produced every year.