removal of anthers from the flower bud of a bisexual flower before the anther dehisces using a pair of forceps and; ii) Bagging i.e. Edutry provide a Assignments where you can Submit Your Assignments. Get ready to learn about pollination in this learning video for kids. How pollination does is achieved in vallisneria and sea grasses? Accordingly, the types of pollination are anemophily or anemogamy (anemos==wind), zoophily or zoidiophily or zoogamy or zoidiogamy and hydrophily or hydrogamy. This is a part of ... Hydrilla, vallisneria. Where and how does it take place? 32. a) What is poultry? Q19 Explain the various steps involved in the production of arti... If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. Cross-pollination, type of pollination in which sperm-laden pollen grains are transferred from the cones or flowers of one plant to the egg-bearing cones or flowers of another. Many animals are involved in pollen transfer Autogamy ,Geitonogamy and Xenogamy. Question 1. Q25 What is an operon ? Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. What is pollination? Pollination is the mechanism to achieve this objective. While sinking, they come in contact with long and sticky swaying stigmas to effect pollination. Practising given Class 12 Biology Chapterwise Important Questions with solutions will help in scoring more marks in your Board Examinations. Pollination is the process of transfer of pollen the male gametes from anther to stigma a female part in the flower of plants. Q24 Explain ‘fitness of a species’’ as mention... There was a significant positive relationship between the effective ‘pollination times’ and pollination rates of flowers (Y = 17.291× − 17.787, r 2 = 0.9605, P<0.001) as well as number of pollen grains per stigma (Y = 1.3669x − 1.8707, r 2 = 0.9606, P<0.001). The female flower, having achieved fertilisation, then closes. Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. In autogamy pollination is achieved within the same flower. With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte. See the process of how a flower multiplies and makes other flowers! Dispersal is achieved via these seeds as well as stolons , which are less tenacious (and thus less potentially harmful) than rhizomes when spreading. Vallisneria produce both male and female plants. What is spermatogenesis? Without it, our food supply would be in trouble. POLLINATION. 3. Whereas we only require two of us to accomplish reproduction, plants have to utilize a third party. Q15 What is disturbance in Hardy-Weinberg genetic equilibrium in... Insects, wind, water, birds, bats, animals and snails are the agents of pollination in plants. Morgan in genetics. Some examples of water pollinated plants are Vallisneria and Hydrilla which grow in fresh water and several marine sea-grasses such as Zostera. Pollination is a fundamental act our plants depend upon for their success. Gymnosperm pollination is invariably anemophilous (primary); only recently evolved genera as Ephedra and Welwitschia are pollinated by insects. Vallisneria (named in honor of Antonio Vallisneri) is a genus of freshwater aquatic plant, commonly called eelgrass, tape grass or vallis.The genus is widely distributed in tropical and subtropical regions of Asia, Africa, Europe, and North America. Pollination. The second tube enters the remaining synergid, and its contents seem to be dis- The general drawing (pl. Based on the agents involved ¡n cross. In Vallisneria, the female flowers are submerged in the water. In vallisneria, the female flower reach the surface of water by the long stalk and the male flower or pollen grains are released into the surface of water. Differentiate between microsporogenesis and megasporogenesis. For harvesting the reward(s) from (b) the flower the animal visitor comesFigure 2.1 (a) Pollination by water in Vallisneria ; in contact with the anthers and the (b) Insect pollination stigma. Your IP: 22.214.171.124 Define ecological pyramid. What is triple fusion? After pollination, the stalks coil and pull the flowers underwater, where they develop into fruits and eventually drop seeds. 2. Q17 Describe the roles of heat, primers and the bacterium Th... All Rights Reserved. The female flower, having achieved fertilisation, then closes. Transfer of pollen grains (shed from the anther) to the stigma of a pistil is termed pollination. Kerala State Board New Syllabus Plus Two Botany Chapter Wise Previous Questions and Answers Chapter 2 Sexual Reproduction in Flowering Plants.. Kerala Plus Two Botany Chapter Wise Previous Questions Chapter 2 Sexual Reproduction in Flowering Plants. The pollen grains stick to the insect, and when it sits on another flower, it rubs the pollen grains to the sticky stigma. Once at the surface, the tiny male flowers float around like little pollen-filled rafts. Q25 Explain how a polycistronic structural gene is regulated by ... Define Interspecific hybridization. Pollination by Water: Pollination by water is quite rare in flowering plants and is limited to about 30 genera, mostly monocotyledons. Pollination often occurs within a species. Pollination does not always ensure the transfer of compatible pollens. Differentiate between a zoospore and a zygote. Give an example. How Vallisneria and seagrasses achieve pollination. Q18 Different animals respond to ch... There is general agreement that early angiosperms were pollinated by Coleoptera and Diptera. Many animals are involved in pollen transfer . How is this achieved? They reach the surface of water by the long stalk on reaching maturity. The usual agents are wind, animals and water. Compare the pyramids of ener... Pollination often occurs within There, through these three agents, viz wind, water and insects, a … Biotic Pollination: This is the most common and also efficient methods of pollination. The male plant bears a large number of minute male flowers in a small spadix surrounded by a spathe and borne on a short stalk, whereas the female plant bears … There is a type of pollination (cross-pollination) you want to avoid, and for some plants, you don’t want them to pollinate at all. It has straight green leaves; the species name "spiralis" comes from the spiraled white flower that may develop above the water level. Unique examples include birds, bats, and even lizards. • Q23 It is commonly observed that pa... One of the ways that plants can produce offspring is by making seeds. The female flowers differ from those of other species of Vallisneria in being bipartite as opposed to tripartite and having the stigma branches arranged above instead of between the sepals. This may be achieved through the use of pollination bags. Briefly describe the process of spermatogenesis. Q13 Explain the process of pollination in vallisneria. How does pollination is achieved in Vallisneria and seagrasses? These are carried by wind and waves to the floating female flowers, which they pollinate. They are then carried by the passive water currents. Q24 Write any two limitations of ecological pyramids. Transfer of pollen grains from the anther to the stigma of the same flower. pollination, the following types of cross pollination are recognised. Many flowers are pollinated without the aid of animals (insect, bird, or mammal). In Vallisneria spiralis, an unopened male flower floats to the surface of the water, and, upon reaching the surface, opens up and the fertile anthers project forward. In estuarine wetlands, the daily periodic tidal activity has a profound effect on plant growth and reproduction. Sexual Reproduction in Flowering Plants Important Questions for CBSE Class 12 Biology Pollination. Pollination from an Evolutionary Point of View. They are carried by water currents reaching the female flowers and the stigma. In autogamy, pollination is achieved within the same flower. Some are pollinated as the currents of wind or water act as vectors. There they will be caught by the female flowers, and pollination will occur. What is an ecological pyramid ? Achieved by man. The stigmas are long and sticky, e.g., Vallisneria, Hydrilla and Zostera. In sea grass, the female flowers are seen submerged in water and the pollen grains are released inside the water. (i)Autogamy is the transfer of pollen grains from anther to the stigma of the same flower. Q20 (a) Explain the significance of "palindromic nucleotide... In Valilisneria, the female flower appear on the surface of the water as it have a long stalk. Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, enabling later fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents are animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. 5. Pollination often occurs within As the breeze tugs at it, so its stem pulls it lower in the water, creating a dimple in the surface. Hence, the pistil has the ability to recognise the right type of pollen to promote post- pollination events. How does it differ from that of bean. Name the nuclei involved in triple fusion. ii. When a pollen grain moves from the anther (male part) of a flower to the stigma (female part), pollination happens. Results showed that the species had very different reproductive allocation in tidal and non-tidal habitats. Q24 Compare, giving reasons, the J-shaped and S-shaped models of... To disperse their pollen of wheat, rice and Bengal gram ( or products... Search for nectar, bird, or mammal ) examples include birds, bats, and bats snails... Bryophytes and pteridophytes web property it different in water-lily, which they pollinate the act of transferring pollen grains the! Pulls it lower in the Vallisneria and Hydrilla which grow in clusters with stems... Be caught by the female flowers and the stigma lie close to each other in a majority... 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