Question

In pineapple (Ananas sativus) the fruit is
a. Pepo
b. Drupe
c. Etaerio of achenes
d. Sorosis

Answer 1

Hint: Fruits can be classified into three main types-
• Simple fruit
• Aggregate fruit and
• Composite or multiple fruits.
A simple fruit is formed from a flower having a single pistil. An aggregate fruit is formed from a flower having polycarpellary apocarpous gynoecium. A composite fruit is formed from a whole inflorescence.

Complete answer:
• Sorosis is a type of composite or multiple fruits.
• Sorosis either develops from a spike or a female catkin.
• Pineapple fruit develops from an intercalary spike of sterile flowers with persistent bracts.
• The enlargement of the peduncle making it fleshy, thus embedding part of the sterile flowers into it.
• The position of the individual flowers is represented by the rhomboidal areas found on the outside of the fruit.
• Bracts remain persistent as small projections.
• The unembedded portion withers away.

Hence, the correct answer is option (D).

Additional information:
• True fruit which is also called eucarp is a ripened ovary. It develops under the influence of ripening ovules. It has a pericarp that is formed from the wall of the ovary and seeds formed from ovules.
• False fruit is a fruit in which other floral parts fuse with the pericarp. False fruit is also known as accessory fruit or pseudocarp.
• Parthenocarpy is a fruit that is formed without fertilization.

Note: Apart from sorosis, the other type of composite or multiple fruit is syconus. It develops from the hypan-thodium type of inflorescence.
• A simple fruit may be dry or succulent.
• Dry fruits can be further classified as achenial, capsular, and schizocarpic.
•Succulent fruits are of three types namely berries, drupes and pomes.
• Pepo is a special type of false berry.
• Etaerio of achenes is aggregate fruits.