For us, ‘fruit’ means a mango, papaya, apple or a banana.
Fruit, the final product of sexual reproduction, develops from an ovary post-fertilisation.
Incidentally, in most cases, fertilisation and the development of fruit triggers the withering of other parts of the flower including the sepals, petals and stamens. However, in some cases like apple, floral parts such as the thalamus become a part of the fruit. Such fruit, in which other parts of the flower besides the ovary are involved in the formation of the fruit, are called false fruit. On the other hand, fruit like mango and papaya that develop only from the ovary are called true fruit. Interestingly, while mango and papaya develop after fertilisation, fruit like banana develop without fertilisation and are called parthenocarpic fruit. Moreover, in the case of banana, the edible parts develop from the inner tissues of the ovary and the brown specks that we see are the remnants of the ovules. If you cut open a fruit, you will see that it is made up of two parts – the pericarp and one or more seeds. The pericarp is the fruit wall that develops from the walls of the ovary. The seed, the second part of the fruit, is actually a fertilised ovule. Typically, a seed is enclosed in a tough outer, protective covering called the seed coat which is actually the hardened integument of the ovule. The ability of the seed to germinate is called seed viability and it varies across seeds of different species. The seeds of spinach, for instance, remain viable only for a year or so whereas musk melon seeds remain viable for five years. Excavations around the Arctic Tundra region have led to the finding of seeds of Lupinus arcticus, which remained viable for 10,000 years before germinating and flowering. Seeds, a character unique to angiosperms, also offer many advantages to these groups of plants. Inside the seed coat lie the embryo, embryonal axis, endosperm and cotyledons. Certain seeds contain more than one embryo and are called polyembryonic seeds. Apoximis is a mechanism that allows a plant to produce seeds without fertilisation.