BIOLOGY INVESTIGATORY
PROJECT
R.MANOJ
12TH STD

STUDY OF DISPERSAL OF
SEED BY VARIOUS
AGENCIES.

INTRODUCTION
 The process of scattering of fruits and seeds to distant places away from
their parent is calle dispersal on dissemination. It provides the new plants
better chances of obtaining water, nutrient light and space thereby
enabling them to have a better start in life.The fruits and seeds develop
many devices for better dispersal through different agenciesThe principal
agencies that aid in the dispersal of fruits and seeds are wind
(anemochory), wit(hydrochory) and animals including man (zoochory).
Besides, some plants show self dispersal by explosimechanism (autochory).
The dispersal through the agency of animals is consideredas the best and
msuccessful method. Dispersal of seeds and fruits is quite interesting
subject of natural phenomenonandhence the study of dispersal of seeds
by various agencies has been selected for the present project.

 AIM:
Study the disperal of seed by various agent.
MATERIAL REQUIRED:
Different types of seeds and fruits, knife, foreceps,
petridishes, hand lens etc.

 PROCEDURE:
 1. Collect different types of seeds and observe their features carefully,
classifythem according ttheir mode of dispersal.
 Similarly cut open different types of fruits, note down the features of their
seeds and classify them according to their mode of dispersal.
 Record your observation in the form of a table .

TYPES OF SEED DISPERSAL
 Seed Dispersal by Wind.
 Seed Dispersal by Water.
 Seed Dispersal by Animal.
 Seed Dispersal by Insect.
 Seed Dispersal by Explosions.

SEED DISPERSAL BY WIND
(anemochory)
 The wind is the natural andfundamental means of seeddispersal in
the plant kingdom.
 This process of dispersal is mainly seen in those plants which bear
very light seeds.
 The seeds of the orchid plant, dandelions, swan plants, cottonwood
tree, hornbeam, ash, cattail, willow herb, are all examples

SEED DISPERSAL BY WATER
(hydrochory)
 In this method of seed dispersal, seeds float away from their parent plant.
 These are mainly seen in those plant which lives in water or nearby the
water bodies like beaches, lakes, ponds etc.
 Coconut, palm, mangroves, water lily, water mint, are a few examples of
plants whose seed are dispersed by the water.

SEED DISPERSAL BY ANIMAL
(ZOOCHORY)
 Seeds can be transported on the outside of vertebrate animals (mostly
mammals), a proces known as epizoochory.
 epizoochorous transport can be highly effective if seeds attach to wide-
ranging animals.
 The seed of these plants gets attached on the fur of animals with the help
of these hooks and are carried away to different places, far from their
parent plants.
 large animal seed dispersers (such as chimpanzees, toucans and hornbills)
may disperse large seeds with few other seed dispersal agents

SEED DISPERSAL BY INSECT
 Insects are very active during the day and visit a variety of wildflowers.
 These are less efficient than bees at moving pollen between plants.
 Insects probe for nectar, their flight fuel, and typically favor the flat,
clusteredflowers that provide a landing pad and abundant rewards.

SEED DISPERSAL BY EXPLOSIONS
 Explosions in fruits literally refer to bursting with all its energy.
 In this case, as the fruits get ripened, it shoots out its seeds into the external
environment.
 This type of seed dispersal is mainly seen in those plants havingpods.
 Okra, Lupins, gorse, and broom are a few examples of plants whose seeds
are dispersed by Explosions.

OBSERVATION:
PLANT
1.Impatiens(balsam)
2.viola(plansy)
3. Acer (Maple), Hopea, Tecoma,
Haloptelia (Chilbil), Shorea (Sal),
Elm, Moringa,Jacaronida,
Cinchoria,Albizia (Siris),Dalbergia
(Shisham) etc.
Characteristics of
seeds/fruits
Capsular fruit, mature fruit burst
open with force when touched
and seeds are shot severalfeet
away.
Fruit capsule, tension developsin
the drying wall of the carpels
causing the fruit to burst open
along mechanismthe line of
dehiscence.
Thin, wing like expansions are
present in seeds/ fruits, Wings
providelarge surface area to the
wind for their dispersal.
Mode of
dispersal/external
agency
Autochory/explosivemechanism.
Autochory/explosivemechanism.
Anemochory/dispersalby wind.

plant
4. Chenopodium (Bathua),Polygonum.
5.Boerhaavia,Plumbagocleome
6.Ficus(Banyan and pipal tree).
7.Crop plants (cereals,pulses,spices etc.
Charecteristics of
seed /fruits
Seed/Fruit verylight, float on the
surface of water.
Fruits are sticky and can stick to
the body of Zoochory animals.
Fruit edible, chiefly eaten by birds,
seeds released unharmed with
faeces.
Fruits/Seeds haveeconomic
importance.
Mode of
dispersal/externak
agency
Hydrochory/dispersalby water.
Zoochory/dispersal by animal.
zoochory/dispersal by bird.
Zoochory/dispersal by man.

CONCLUSION:
Seeds have the ability to germinate in the
presence of moisture, air, and light under the
right temperature, even in the absence of soil.
If you are interested in knowing more about
seed germination, you can repeat the same
experiment but keep the bag in a dark place
instead of placing it in light.