Reproduction In Organisms

Sucker is a mode of vegetative propagation. It is a non- green slender stem branch which arises from the underground base of erect shoot or crown. It grows horizontally in the soil and ultimately comes out to form a new aerial shoot or crown. Each sucker has nodes with scale leaf and axillary bud. For example, mint has the sucker. It has adventitious root and scale leaf.

Runner is a slender, prostrate, subaerial branch that creeps horizontally on the soil. It develops from the lower axillary bud of stem and is thin elongated cylindrical structure with long intemodes. When the intemodes break due to rotting or by any other reason, the nodes with adventitious roots develop into daughter plants. E.g., Oxalis, Cynodon.

Kalanchoe reproduces vegetatively by epiphyllous or foliar buds. These are adventitious buds produced in the notches at the tip of lateral veins. These buds start sprouting on the leaf to form leafy shoot and adventitious roots.

Motile zoospores are produced by many algae e.g., Chlamydomonas.

In flowering plants (angiosperms), the ovary of the flower develops into the fruit after fertilization. The ovary, part of the pistil, contains one or more ovules. Following fertilization, the ovule develops into the seed, while the ovary wall thickens and matures to form the fruit, which protects the seeds and aids in their dispersal. The fruit may be fleshy (e.g., mango) or dry (e.g., pea pod), depending on the plant species.
The roles of the other structures are:
- Ovule: Develops into the seed after fertilization, containing the embryo and endosperm.
- Anther: Part of the stamen, produces pollen grains (male gametes), not involved in fruit formation.
- Stigma: Part of the pistil, receives pollen during pollination, but does not develop into fruit.
Thus, the structure that develops into the fruit after fertilization is the ovary.

Double fertilization is a unique feature of flowering plants (angiosperms). During this process, two male gametes from a pollen tube fertilize two cells within the ovule:
- One male gamete fuses with the egg cell to form a diploid zygote, which develops into the embryo.
- The other male gamete fuses with two polar nuclei in the central cell to form a triploid primary endosperm nucleus, which develops into the endosperm, a nutritive tissue that provides nourishment to the developing embryo.
The other options are incorrect:
- Seed coat: Develops from the integuments of the ovule, not from double fertilization.
- Pollen grain: Produces male gametes but is not a product of fertilization.
- Ovule: The structure that contains the egg and develops into the seed after fertilization, not a direct product.
Thus, double fertilization results in the formation of the embryo and endosperm.