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Posts : 2
Join date : 2010-08-11
|Subject: Re: Seed Dispersal Tue Oct 19, 2010 12:36 am|| |
Seeds and fruits dispersal dispersal:
Seeds need to be dispersed away from the parent plant. Because if the young plant remains close to its parent,
it would need to compete with the parent for resources needed. Dispersing seeds and fruits is the separation of
the parent to avoid competition
Dispersal methods can be by:
-Wind: Some seeds are enclosed in wing-like husks (with one or two propeller blades) or fluffy coverings that help
them drift some distance away from the parent plant.
-Water: The fruits of most water plants have buoyant, waterproof coverings that allow them to float and disperse
their seeds by water.
-Animals: Animals often serve as seed carriers. Seeds (with sticky hairs, bristles, hooks, or barbs) are transported
by sticking to the fur of animals
-Exploding mechanism: Some fruits scatter their seeds by literally exploding. The pod dries, bursts open and forcibly
shoots the seeds for several feet in all directions.
Seed dispersal by wind (scyamore) example
The sycamore seeds are small and light enough that they fly into the wind when it blows across the tree.
The seeds land far away and take root. Apple seeds, on the other hand, are held inside a heavy fruit that falls
straight down to the ground. If the seed took root there, it would die in its parent's shadow.
However, this doesn't happen because the apple will usually be eaten by an animal. Later, the animal eventually
excretes the waste from its meal, which will include the indigestible seed. That's how the apple seeds move
from the parent tree's location.
Posts : 2
Join date : 2010-08-12
|Subject: Re: Seed Dispersal Sun Oct 24, 2010 12:29 pm|| |
The different methods of seed dispersal are considered to make sure that as many seeds as possible have the ability of growing up in different places to produce new seeds of their own and to avoid overcrowding
The different types of seed dispersal are the following:
-By animals: fruits are attractive and liked to animals, for example, raspberries and sea grapes. When the animal eats the fruit the seeds are not digested so they pass throw the animals defecation.
-Wind: Is one of the main agencies of seed dispersal, some seeds, are made to catch with the wind, this way the blow away and hopefully they land far away for the specie to develop.
-Water: Plants which grow beside water often rely on water to transport their seeds for them.
-Explosive mechanism: Some plants have pods that explode when ripe and shoot out the seeds.
- Catching a lift: some fruits have little tiny hooks on them, these hooks catch on passing animals if they meeting against the plant and get carried away.
This flower can grow till 4.5m, it’s a floating plant and it has big leaves that float under water.
This plant emerge from water to have pollination for the fruit to be formed and then it goes under water again until the dispersing seed moment arrives, this always happens under water so the process cant be shown.
|Subject: Re: Seed Dispersal Tue Oct 26, 2010 6:12 pm|| |
There are lots of diferent types of pollen dispersal everithing can make this vary, the form of the plant, were geographic area does the plant live, etc. The important point is to fertilize the most plants possible to mantain the specie in the Earth.
We can separate the type of dispersal by:
Wind: There are plants in the world which have the pollen hanging in the extremities so it is very easy for the wind to take the pollen flying away until it reaches other plant in the area. Example: Dandelion.
Water: There are plants that their pollen is waterproof this are mainly plants that live beside water so it uses water as a way of transporting pollen.
Humans & animals: Many humans or animals walking by a place were is full of flowers they can pass by and by this movement can disperse in the air the pollen that will probably arrive to a stigma.
Andres Sanfuentes 1°B
Posts : 3
Join date : 2010-08-05
|Subject: Re: Seed Dispersal Thu Oct 28, 2010 5:14 pm|| |
Seeds disperse, getting out of the flower and travel to different places of the world so the flower specie gets to different places. They are many different ways in which this can occur.
-The first one is by wind, some plants are light enough to get carried away and land as far as they can.
-Some other seeds can float over water because they are resistant to water.
-Another seeds can resist digestive juices a animal has, this happens because the animal eats the fruit with the seed included and later excretes the seeds.
-A very strange method is by explosive mechanism, this time the plant burst open throwing seeds everywhere.
-My weird kind of seed dispersal is the shaking method, with this method when wind hits the plant, shaking it, the plant drop little seeds out of the top through little holes.
Information taken from http://www2.bgfl.org/bgfl2/custom/resources_ftp/client_ftp/ks2/science/plants_pt2/dispersal.htm
|Subject: irrazabal Thu Oct 28, 2010 10:32 pm|| |
Dispersal of seeds: wind, animals, water, self dispersion.
Dandelion seeds have developed very light and fluffy parachute-like structures. These help the seeds to float in the wind and delays their fall to the ground. This delay allows the seeds to be carried further. The largest and heaviest wind-dispersed seeds, such as Sycamore cannot rely on hair-like parachutes to keep them airborne. They would have to be enormous to be effective. Instead they have developed a wing which causes them to spin through the air like mini helicopters. This again delays their fall.
Posts : 2
Join date : 2010-08-12
|Subject: Seeds Dispersal Thu Oct 28, 2010 11:35 pm|| |
One of the important functions of seeds is dispersal
; which is a mechanism to establish the seeds in a suitable place away from their parental plants.
Nearly all seeds are produced within fruits. These fruits enable seeds to be dispersed in a variety of ways;
the first one is by wind
; some seeds are adapted to catching the wind and being blown away such as sycamore or dandelion
By an explosive mechanism
; these seeds suddenly open throwing the seeds in all directions, such as peas, laburnum or gorse
; some seeds are waterproof and can float. For example, coconuts
Another good example of seed dispersal is by animals
. Lots of fruits are really tasty to animals (and humans), such as blackberries, apples and gooseberries
. When an animal eats these fruits the little seeds are not digested and pass through the animal defecation.SUNFLOWER SEEDS
Sunflower seeds could be dispersed by wind, they form structures that resemble tiny parachutes. The upper portion of the parachute, called the pappus, resembles hair and is very lightweight. A stem attaches to the pappus, and at the bottom of the stem is the seed of the sunflower. Wind catches the pappus and lifts the seed from the plant and into the air current. Some types of sunflowers do not form pappus structures. These are transported most commonly by birds or animals who disrupt the seed from its position on the plant, intentionally or unintentionally. Seeds also could fall on the ground and can be kicked around by people and wildlife, or transferred when the dirt around the plant is transferred, such as during landscaping.
Sunflower seeds are particularly popular in Mediterranean and Asian countries, like Syria, Israel, Turkey, and Malaysia, and also in countries worldwide like Russia, Ukraine, Bulgaria, Romania, Spain, China, Iran, Canada, and the United States.
|Subject: Seed Dispersal Mon Nov 08, 2010 1:34 am|| |
For the seed development it is necessary to give the plant water, sunlight and CO2. But first the plant has to distribute it seeds in different areas. This process is named seed dispersal, which can take place in three different ways, transporting the seeds:
1. By wind: naturally, when the wind blows, causes the seed to fall from the plant to the ground near it’s area, to make another plant grow.
2. By water: this ocurs when the rain carries the plant’s seed. The seed can be transported far away by the water’s strength. Some seeds have waterproof characteristics which protects them from getting damaged.
3. By animals: in this method an animal can carry the seed inside or outside it’s body, this means that the animal can ingest the food and when wastes products comes as feaces the seeds come too.
Seed dispersal example:
The ash is produces by a tall tree which produce seeds with stiff wings covering the seed that enable them to fly long distances. The wings are twisted and balanced so that the ash seed spins around as it is carried along by the wind. These natural adaptations for using the wind to transport the weight of the seed must be technically accurate, as the wings of modern planes and helicopters are designed in the same way.
|Subject: Re: Seed Dispersal || |