Hint: In fleshy fruits, the pericarp is made of three different layers. The outermost layer is the epicarp, also known as the exocarp, the middle layer is the mesocarp, and the endocarp is the inner layer, which is surrounded by the ovary of seeds. In cucumber, the mesocarp and endocarp are both edible parts.
Complete answer:
Cucumis sativus or the cucumber is a widely cultivated plant that belongs to Cucurbitaceae, the gourd family. The cucumbers are roughly cylindrical, elongated with tapered ends. They are likely to have an enclosed seed that is developed from a flower. Thus, the cucumbers are classified as accessory fruits, whose fleshy part of the fruit is not derived not from the ovary but is derived from some adjacent tissues of the carpel. The outer layer of the ripened ovary or fruit that is developed from the ovary wall of the flower is known as pericarp that is surrounded by the seeds inside the fruit. It comprises three distinct layers of the pericarp area, the epicarp, mesocarp, and endocarp.
The tough outer layer of the skin of the fruit, which is peeled in certain fruits, is known as the epicarp. It is a protective layer that aids in protecting the inside of the fruit.
The middle layer of the pericarp that is present between the endocarp and exocarp is the mesocarp. This layer contains plastids that impart color to both the ripe and unripened fruits. It is the fleshy part of certain fruits. It is the edible part of most of all fruits. This part of the cucumber is rich in water content and is consumed. The innermost layer of the pericarp, which is surrounded by the seeds in the fruit is known as the endocarp. It can be a hard-membranous seed or even a soft one. This layer enhances the protection of seeds, seed dispersal, helps in the communication of seed with other parts, and the development of seeds within the fruits.
Hence, the correct answer is option (C).
Note: The Cucumis sativus belongs to the gourd family of Cucurbitaceae, which is one of the widely cultivated plants. It has a fruit that is cylindrical, elongated with tapered ends, with the enclosed seed that is developed from a flower. In cucumber, the thickened part of a stem or thalamus, pericarp (with all three layers), and the placenta, which connects the ovules inside the ovary.
