2 Biology Investigatory Project

April 3, 2018 | Author: Gorib Manush | Category: Plants, Botany, Plant Reproduction, Horticulture And Gardening, Horticultural Techniques


Comments



Description

2015-16Biology INVESTIGATORY PROJECT Dispersal of Seeds Anirudh Murali Chaitanya Techno School Bangalore BIBLIOGRAPHY . THEORY 6. ACKNOWLEDGEMENT 3. CERTIFICATE OF EXCELLENCE 2. 8. MATERIAL REQUIRED 7. INTRODUCTION 5. EXPERIMENTAL PROCEDURE.INDEX 1. OBSERVATION 9. CONCLUSION 11. AIM OF PROJECT 4. DEPARTMENT OF Biology CERTIFICATE This is to certify that Anirudh Murali. a student of class XII has successfully completed the research on the below mentioned project under the guidance of __________ ( Subject Teacher ) during the year 2015-16 in partial fulfillment of physics practical examination conducted. Signature of external examiner of Biology teacher Signature . many people have best owned upon me their blessings and the heart pledged support. whose valuable guidance has been the ones that helped me patch this project and make it full proof success his suggestions and his instructions has served as the major contributor towards the completion of the project. Then I would like to thank my principal________ and Biology teacher ________. this time I am utilizing to thank all the people who have been concerned with project. Last but not the least I would like to thank my classmates who have helped me a lot. Then I would like to thank my parents and friends who have helped me with their valuable suggestions and guidance has been helpful in various phases of the completion of the project. . Primarily I would thank god for being able to complete this project with success.ACKNOWLEDGEMENT In the accomplishment of this project successfully. Besides. It provides the new palnts better chances of obtaining water.Aim To Study of Dispersal of Seeds by Various Agencies INTRODUCTION The Process of scattering of fruits and seeds to distant places away om their parent is caalled dispersal on dessemination. The dispersa l through the agency of animals in consideredas the best and most successful method.Dispersal of seeds and fruits is quite Intresting subject of natural phenomenon and hence the study of dispersal of seeds by various agencieshas been selected for the present project. some plants show self dispersal by explosive mechanism (autochory). Dispersal thorugh agency of animals is considered as the best and most successful method. The fruits and seeds develop many devices for better dispersal through different agencies. . nutrients. water (hydrochory) and animals including man (zoochory). lights and space thereby enabling them to have a better start in Life. The principle agencies that aid in the dispersal of fruits and seeds are wind (anemochary). 2. reach nutrient-rich microsites an d survive longer than other seeds. and often defecate seeds beneath these perches where the seeds have a high chance of survival because of high light conditions and escape from fungal pathogens. seed dispersal may allow plants to colonize vacant habitats and even new geographic regions. and the asynchrony of germination. Seed dispersal also allows plants to reach specific habitats that are favorable for survival. In the case of fleshy-fruited plants. at another scale. which may thus provide additiona l benefits not present in other dispersal modes. 5. Competition with adult plants may also be lower when seeds are transported away from their parent.Theory Benefits Seed dispersal is likely to have several benefits for plant species. which often target the high concentrations of seeds beneath adults. These features are peculiar to myrmecochory.Seeds dispersed by ants (myrmecochory) are not only dispersed short distances but are also buried underground by the ants. 4. which c an have important plant benefits. a hypothesis known as directed dispersal. Seed survival is often higher away from the parent plant. Finally. 3. This higher surviva l may result from the actions of density-dependent seed and seedling predators and pathogens. Male bellbirds perch on dead trees in order to attract mates. seed-dispersal in animal guts (endozooc hory) often enhances the amount.Barochory or the plant use of gravity for dispersal is a . Gravity (Autochory) 1. 1. the speed. These seeds can thus avoid adverse environmental effects such as fire or drought. Wind Allochory * Wind dispersal of dandelion seeds Entada phaseoloides â Hydrochory Wind dispersal (anemochory) is one of the more primitive means of dispersal. The effect of gravity on heavier fruit s causes them to fall from the plant when ripe. 2 Two other types of autochory are ballochory (the seed is forcefully ejected by dehiscence and squeezing) and herpochory(the seed crawls by means of trichomes a nd changes in humidity). An important constraint on wind dispersal is the need for abundant seed production to maximise the likelihood of a seed landing in a site suitable for germination. Wind dispersal can take on one of two primary forms: seeds can float on the breeze or alternatively. Reliance on wind dispersal is common among many weedy or ruderal species. which have a feathery pappus attached to their seeds and can be dispersed long distances. which have winged seeds (samara) and flutter to the ground. However. Fruits exhibiting this type of dispersal include apples.simple means of achieving seed dispersal. * The classic examples of these dispersal mechanisms include dandelions. . and maples. Gravity dispersal also allows for later transmission by water or animal. limited wind in its habitat prevents the seeds to successfully disperse away fro m its parents. resulting in clusters of population. the y can flutter to the ground. coconutsand passionfruit and those with harder shells (which often roll away from the plant to gain more distance). If they grow near oceans. allowing the seeds to be dispersed as far as other continents.Water (hydrochory) Many aquatic (water) and some terrestrial (ground) plant species use hydrochory. The water lily is an example of such a plant. Plant species transported externally by animals can have a variety of adaptations for dispersal. or seed dispersal through water. The seeds of palm trees can also be dispersed by water. spines and barbs. the seeds can be transported by ocean currents over long distances. Water lilies' flowers make a fruit that floats in the water for a while and then drops down to the bottom to take root on the floo r of the pond. all named zoochory. Seeds can be transported on the outside of vertebrate animals (mostly mammals). depending on the specific mode of water dispersal. a process known as epizoochory. By animals (zoochory) The small hooks on the surface of abur enable attachment to animal fur for dispersion. including adhesive mucus.Animals can disperse plant seeds in several ways. Seeds can travel for extremely long distances.This is because some fruits ar e waterproof and can float. and a variety of hooks.The small hooks on the surface of abur enable . Dispersal by humans (anthropochory) used to be seen as a form of dispersal by animals. nutritious fruit as a good food for animals that consume it. However. Seed predators. which include many rodents (such as squirrels) and some birds (s uch as jays) may also disperse seeds by hoarding the seeds in hidden caches. regional scales and drives the dynamics of existing biological populations. Classif y them . the percentage of plant species with seeds adapted for transport on the outside of animals is estimated to be below 5%. rodents may also disperse seeds via seed spit ting due to the presence ofsecondary metabolites in ripe fruits. Seed dispersal via ingestion by vertebrate animals (mostly birds and mammals). Collect different types of seeds and observe their feature carefully. ornithochory (by birds) and saurochory (by non-bird saurops ids).Different types of seeds and fruits.Petridishes . single s cases > 100 km). Experimental Procedure.on shoes (up to 5 km) or by cars (regularly ~ 250m.Hand lens etc. mainly terrestrial snails). Birds and m ammals are the most important seed dispersers. inc luding turtles and fish. is the dispersal mechanism for most tree species. but a wide variety of other animals.Knife.The seeds i n caches are usually well-protected from other seed predators and if left uneaten will grow into new plants. malacochory (by molluscs. Other types of zoochory are chiropterochory (by bats). Material Required.Dispersal by humans on the one hand may act on large geographical scales and lead to invasive species.Humans may disperse seeds by many various means and some surprisingly high distances have been repeatedly measured. 1. can transport viable seeds. In addition. Recent research points out that human dispersers differ from animal dispersers by a much higher mobility based on the technical means of human transport.Foreceps. epizoochory is a relatively rare dispersal syndrome for plants as a who le. On the other hand.attachment to animal fur for dispersion.Endozoochory is generally a coevolved mutualistic relationship in which a plant surrounds seeds with an edible. o r endozoochory. Examples are: dispersal on human clothes (up to 250 m). dispersal by humans also acts on smaller. Viola (Pansy) Fruit capsule. 4. Acer(Maple)Hopea.Heloptelia (Chilbil).Moringa. Sonchus Fruit single seeded cypsela Anemochary/Dispersal . Elm. Tecoma. Record Observation Observation: S.Shorea(Sal).Jacornida. 2.Dalbergia (Shisham) Thin wing like expansion are Anemochary/Dispersal present in seeds/Fruits.No Plant Characteristics of Seeds/Fruits Mode of Dispersal/External Agencies Autochory/Explosive mechanism 1 Impatiens(Balsam) Capsulsular Fruit. note down the feature of their seeds and classify them according to the mode of dispersal. Dandelion. Cinchoria. 3. provide large surface area to the wind for their dispersal. 2.Albiziz (Siris). 3. Similarly cut open different types of Fruits.Wings by wind.tension develops Autochory/Explosive in the drying wall of the mechanism carpels causing the fruit to Burst open along the line dehiscene.according to their mode of dispersal.Mature Fruit burst Open with Force when touched and seeds are shot several feet away. Bombax (Sembal) Seeds have hairy outgrowth to providelarge surface area to the wind 6. Hydrochory/Dispersal by water . Calotropis (Ak). Alstonia. 5. Cocus (Coconut) Spongy thelamus or spongy Mesocarp of the fruit. by water 7.with a tuft of hair(pappus) ay by wind. Nelumbiam (Lotus). Nymphea (Water Lily).Polygonum Seed/Fruit very light. Pappus open up like a parchute.Float on Hydrochory/Dispersal the surface of water. Anemochary/Dispersal by wind. Chenopodium (Bathua). upper end. Cordia Seeds are sticky and seeds stick to the beek of the Birds. and in recent times dispersal ability is an important factor in whether or not a species transported to a new habitat by humans will b ecome an invasive species. 11. Madicago attach with fur of the animal. Boerhavia. 12. spices) Fruits/Seeds have econimic Importance. barbs. (Maina). Ficus (Banyan & Pipal Tree) Fruits edible.8. Zoochory/Dispersal by Birds Zoochory/Dispersal by Man CONCLUSION Seed dispersal has many consequences for the ecology and evolution of plants. chiefly eaten by Zoochory/Dispersal by birds. to the body of animals. animals 9.hooks.Plumbago.seeds released Birds unharmed with faeces. Xanthium.Dispersal is also predicted to play a major role in the orig . Achyranthus Fruits and seeds have Zoochory/Dispersal by (Phuthkanda). Viscus.Cleo Fruits are sticky and can stick Zoochory/Dispersal by me. Crop Plants(Cereals. Di spersal is necessary for species migrations.Martynia (Tigers Claw) 10 Loranthus.or spines to get animals Tribulus.pulses. The transportation of seeds is led by the wind direction.in and maintenance of species diversity. The wind dispersal process can also effect conn ections between water bodies. wind plays a larger role in the dispersal of . Dispersal of seeds away from the parent organism has a central role in two major theories for how biodiversity is maintained in natural ecosystems.. This effects colonization situated on the banks of a river or to wetlands adjacent to streams relative to the distinct wind directions.Seed dispersa l is essential in allowing forest migration of flowering plants. Essentially. the speed and direction of wind are highly influential in the dispe rsal process and in turn the deposition patterns of floating seeds in the stagnant wa ter bodies. In addition. BIBLIOGRAPHY ï · ï · ï · ï · HELP FROM INTERNET & Wikipedia INFORMATION FROM LIBRARY HELP FROM TEACHERS Comprhensive Lab Manual J. The time period of which the dispersal occurs is essential when considering the cons equences of wind on the ecological process. but the ecological process allows the process to become balanced throughout a time period of several years.Sharma .P.waterborne seeds in a short period of time. days and seasons.
Copyright © 2024 DOKUMEN.SITE Inc.