Question

Simple sieve plate occurs in
A. Cucurbita
B. Vitis
C. Pyrus
D. Prunus

Answer 1

Hint: Sieve plates are the plates that are found on the end walls of sieve tube elements, where the individual cells are joined together to form a longitudinal series called sieve tube. The sieve plates have a larger pore than the other sieve areas in the cell. They are present at the outer end wall of a sieve tube element and help in transport of nutrients.

Complete answer:
The vascular system in the plant body is an essential system of life of a plant as it helps in transportation of the nutrients acquired by the plants to other parts of the plant body. Sieve plates contain perforated surfaces which help in movement of the nutrients which help in movement of nutrients to stem and leaves from the roots, which help in uptake of nutrients from the soil. The vascular system of the plant body including sieve plates, runs through the inner bark of the trees which facilitate the movement upward towards leaves.
In phloem tissue of the plant, sieve tubes possess the perforated oblique or transverse sieve plates. There are two types of sieve tubes which are simple and compound. When a sieve plate consists of one region of pores it is known as a simple sieve tube like in cucurbits, Nicotiana. When they possess several pored regions separated by bars or thick walls it is called compound sieve tubes like in Vitos.

Hence, the correct option is A. Cucurbita.

Note: Cucurbita is a genus of herbaceous plants which belong to the family Cucurbitaceae which is native to Andes and Mesoamerica. There are five domesticated species of Cucurbita which are Cucurbita argyrosperma, C. ficifolia, C. moschata, C. pepo and C. maxima. Fruits of Cucurbita are good in vitamin A and vitamin C along with other nutrients.