Reproduction in Organisms Test - 3

The tubers are modified underground stem branches having several buds. Each eye of the potato tuber is a bud which grows into a new potato plant.

Organisms belonging to Kingdom Monera lack a nuclear membrane. Their nuclear material lies distributed in the cytoplasm.

The incubation period is the time elapsed between exposure to a pathogenic organism, a chemical or radiation and when symptoms and signs are first apparent. Pre-patent period is the period between infection with a parasite and the demonstration of the parasite in the body. Blastulation is the early developmental stage of an animal consisting of single, spherical layer of cells enclosing a hollow central cavity.

Propagation through tubers occurs in potato. Propagation through suckers occurs in mint and Chrysanthemum. Propagation through bulbs occurs in onion, lilies and garlic.

In grafting, the point where the stock and scion are joined is sealed off with wax and clay to prevent the entry of pathogens and prevent the loss of water due to evaporation.

The scion is derived from a plant possessing better characters. Therefore, the quality of fruits produced will be determined by the quality of the scion. For example, a scion of Dussehri mango is grafted on the stock of a Desimango.

The edible part of cauliflower is the inflorescence which we use as a vegetable.

Vegetatively propagated plants are genetically similar. They form true roots, buds and shoots.

The embryo sac is a structure within a plant ovule which contains the egg cell. It develops from the megaspore and contains the embryo plant and endosperm after fertilisation.

Sexual reproduction involves mixing of parental genetic material. This results in new genetic combination leading to variation which contributes to evolution of species.