Reproduction in Organisms Test - 1

Underground modified stems such as suckers of Chrysanthemum arise from the base of the erect shoot. They arise from the basal, underground part of the main stem, which grows horizontally in the soil and then comes out to form new aerial shoots. These shoots become independent plants when suckers break away from the parent plants.

Both the statements are correct. Grafting is done between the two closely related dicots or gymnosperms because of the presence of continuous vascular cambium between the xylem and the phloem. It is also the better method of mass propagation where uniformity in plant characteristic is desired in shortest time possible.

Auxins are compounds that influence cell enlargement, bud formation and root initiation. Auxins, especially Indole-3-butyric acids, are commonly applied to the cut surface that stimulate root growth when taking cuttings of plants.

A bulbil is a miniature clone of the parent plant. Several species of Agave create bulbils on their flower stalks. They are small plantlets grow from a bud at the base of the flower. Many agaves form dozen of these plants after falling on the ground.

Spores that have been recorded from Rhizopus or Mucor are non-motile multinucleate spores that are produced inside the sporangia, hence also referred as endospores. They are usually dispersed by wind and germinate to produce new mycelium.

Planarians divide by transverse binary fission. The cytoplasm divides transversely between two sets of nuclei and forms two dissimilar individuals.

An infected female Anopheles mosquito injects sporozoites into the bloodstream, which later enter into the liver. Within hepatocytes, the asexual multiplication occurs and sporozoites undergo many nuclear divisions to become schizont.

Sporulation is the multiple fission, in which the products of fission become individually surrounded by resistant coats, the cyst walls, before they get detached from the parent. The encysted products are termed as spores. The spores remain inactive during unfavourable conditions, such as desiccation and temperature variations. Hence, sporulation not only brings multiplication but also enables the organisms to survive during unfavourable conditions.

Daucus carota, commonly known as carrot, is a biennial plant which is monocarpic. The plant requires two years to complete its life cycle. During first season of growth, small rosette of leaves near the soil appears followed by stem elongation, flowering and seed formation, which is the second season's growth. The plant then eventually dies.

Monocarpic-perennials have a unique life-cycle. The plant can live up to forty years and die after they flower the first time. Bamboo plants are monocarpic-perennials because they flower only once in their life-time and that too nearly after 50-100 years of vegetative growth.