Quiz 31: Plant Growth and Development
Gazania flower is fiesta red in color and it belongs to the family of Asteraceae. The following pollination vectors carry out pollination in these flowers: • Bees and butterflies or moths: As these flowers are bright red in color and open during daytime, these flowers attract bees and butterflies to carry out the process of pollination. Pollination by insects is known as entomophily. Gazania flowers are large, brightly colored, contains nectar in special glands, edible pollen which attracts insects. In search of nectar the insects dust the stigma with pollen grains. Edible pollen attracts the bees, which in search of wax carry out the process of pollination. • Birds: Pollination carried out by birds is known as ornithophily. Birds visit these flowers for sucking nectar. The following pollination vectors are ruled out as Gazania flowers do not possess the characteristics which are required for the process of pollination to be carried out by these vectors: • Wind: Pollination by wind is known as anemophily. Wind pollinated flowers are usually small, light, lack nectar and scent, are not brightly colored. They posses hairy stigma to catch the dry, small and light weight pollen grains. Wind pollinated flowers invest much amount of their energy in producing large amounts of pollen. • Bats: Pollination by bats is known as cheiropteriphily. The flowers which are pollinated by bats are usually very large, produce large amount of nectar and they usually open at night.
The sporophyte, which bears flowers, roots, stems and leaves, dominates the lifecycle of flowering plants. The sporophytes have diploid number of chromosomes which produces the gametophytes in their life cycle. Hence, the correct answer is option (a). Gametophytes have haploid number of chromosomes and produces gametes. Gametophytes bear the reproductive structures of the flowering plants and produces male and female gametes. Fertilization of male and female gametes develops into sporophytes. Megaspore is the female gametophyte of the flowering plants. The megaspores are produced within the megasporangium of the flowering plants by meiosis. Microspore is the male gametophyte of the flowering plants. The microspores are produced within the microsporangium of the flowering plants by meiosis.
The various types of flowers growing in my area and the type of pollination vectors they depend on are the following: • Rose: Rose belongs to the family of Rosaceae. These flowers are brightly colored like red, yellow, pink, orange. Pollination in these flowers is usually carried out by means of bees, moths, butterflies and birds. These flowers bloom during daytime, which attracts bees and butterflies to carry out the process of pollination. Insects visit these flowers as they contain nectar in special glands and edible pollen. In search of nectar the insects dust the stigma with pollen grains. Edible pollen attracts the bees, which in search of wax carry out the process of pollination. • Marigold: Marigold belongs to the family of Asteraceae. These flowers are also brightly colored like red, yellow and orange. Pollination is carried out in these flowers by means of bees, moths, butterflies and birds. • Jasmine: Jasmine belongs to the family Oleaceae. These flowers are small, white in color, bloom at night and possess scent. Pollination in these flowers is usually carried out by winds and bats. Bats and other nocturnal insects are attracted to these flowers through its smell. These flowers also produce large amount of pollen for pollination to take place by means of wind. They posses hairy stigma to catch the dry, small and light weight pollen grains. • Water lily: The nearby pond is beautified by blooming pink and white water lilies. These flowers belong to the family Nymphaeaceae. These flowers are usually pollinated by water and this process is known as hydrophily. Pollination is also carried out by snails and slugs in water and this form is known as malacophily. Bees and butterflies also visit these pink colored water lilly flowers and dust their stigma with pollen grains and complete the process of pollination.