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PostSubject: Seed Dispersal   Wed Sep 22, 2010 11:48 am

After fertilisation the seeds are attached to the parent plant. These seeds need to be dispersed away from the parent plant and others to reduce competition for resources such as light energy and water. Your task for this forum is to investigate the variety of different ways in which plants are able to disperse their seeds.

1) Please read pages 192-193 ´Dispersal of seeds and fruits´for background information on this topic.

2) Watch the video below about some interesting ways in which seeds are dispersed.

3) Research on the internet to find one interesting example of seed dispersal. You must attach a picture of the seed and also write a summary of at least 150 words about its stucture and method of dispersal. You may include some other interesting information about the seed also.


IMPORTANT: You must not choose a seed from the textbook or the video. You must not choose a seed which your classmate has already chosen and added to the forum!!!


DUE DATE: You must post your forum by the start of your second class during Week 29 (11/10/10)


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francisca.caballero



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PostSubject: Francisca Caballero 1ºmedio B Seed Dispersal   Mon Sep 27, 2010 11:30 pm

Plants need to disperse their seeds away from themselves to the over crowd and to create new seeds. There are different ways in which seeds can disperse.
1. wind: some fruits are adapted to catching the wind and beign blown away.
2. water: some fruits are waterproof and can float
3. By animals: lots of fruits are liked by animals and humans. Like apples and blackberries. When an animal eats these fruits the seeds are not digested and pass through the animal.
4. By an explosive mechanism: the fruits open throwing the seeds in all directions such as peas.
5. Catching a lift: some fruits have little tiny hooks on them, this little hiiks catch on passing animals if they brush against the plant and get carried away
If the seeds simply fell and grew beneath the parent plants they would be too overcrowded and would be starved of nutrients. So it is important that the seeds are dispersed over a wide area where they stand a better chance of finding the right condition to grow.
One of the intresting seeds I found was the seed of the aquatic plants called neunefares

http://blogueiros.axena.org/wp-content/uploads/2009/06/nenufar1.jpg

This flowers emerge from water to have polinisation for the fruit to be formed and then go under water again till the momen of dispersing seeds arrive. This part of the process its always down water so we dont see thw process. So in order ti see the fruit you need to take it of water. Its green, oval and little fruit. That when you open it has little red seeds over a spongy white mass. Well the last character in the story is the galapagos turtle, because they have found out that the fruit can be eaten and in summer is more conftorble to eat of this fruits than other ones. This flowers win a bigger disperse of seeds because the turtles can retain the seeds for one week. The nenufar is the most known aquatic plant. In Egypt it was considered that the plants were sacret because they open with presence of the sun and close with the dark. It has two types of leaves.
1. big leaves that grow under water
2. Floating plants
The roots are very long they can grow till 4.5m.



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Joachim.Speidel



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PostSubject: Seed Dispersal Joachim Speidel 1E def7   Sat Oct 02, 2010 12:44 pm

By Wind: Some plants have characteristics that help the seed be blown away by the wind, being dispersed. (eg. The Sycamore and Dandelions)
By Water: Some seeds (eg. Coconut) Have a waterproof shell that lets it float in water.
By Animals: The seed goes through the digestive juices and is removed by faeces.
By an Explosive Mechanism: The plant blows the seeds away in different directions (eg. The Lupin)
Living Courier: The seed has a specific shape that allows it to attach to fur or skin, and travel a certain distance until it is removed or picked off.
A Plant I found interesting was the Saguaro Cactus, they are a large, tree-sized cactus found in deserts, such as in Arizona, USA. They have a really long life span, they take about 75 years to develop a side arm, the arms are grown to increase the plant’s reproductive capacity. White and yellow flowers appear on it April through June, and a sweet, ruby coloured fruit matures by the ends of June. Saguaro flowers are self-incompatible, and require pollination. Big amounts of pollen are needed for full pollination, as there are lots of ovules. A well pollinated fruit will contain several thousand tiny seeds. The major pollinators are bats, they feed on the nectar of night-blooming flowers, which often stay open until the morning. A factor that attracts bats to it is a fragrance that is emitted at night. The flowers that remain until daytime are pollinated by doves and bees.
The largest known saguaro is the Champion Saguaro. It grows in Maricopa County, Arizona, and is 13.8 meters (45.3 ft) tall with a girth of 3.1 meters (10 ft). These cacti can grow anywhere from 15 to 50 feet.
Local tribes eat the fruit, and use the remains of the plant for construction.
http://upload.wikimedia.org/wikipedia/commons/d/d3/Saguaro_cactus_in_Arizona.jpg
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vicente.suarez



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PostSubject: Re: Seed Dispersal   Tue Oct 12, 2010 6:28 pm

By Wind: some seeds have shapes that help them blew with the wind
By Animals: The seeds can resist digestive juices and then be released
By Water: Some seeds can resist water and float
Living Courier: The seed can be attached to fur,cloths and skin and be carried away
By an Explosive Mechanism: the fruit blows away many seeds scattered
gravity: If the fruit have a soft skin, they may break open when they hit the ground and the individual seeds may be scattered
vanilla cactus:
This fleshy, creeping shrub with cylindrical branching stems, has clusters of small spines in radiated forms. Terminal and lateral flowers up to 30cm in diameter emerge from the clusters of spines, expanding in the evening and lasting for about 6 hours; they are vanilla scented. The petals are white and spreading, shorter than the sepals which are linear, lanceolate, brown outside and yellow inside. The ovate fruit is covered with scaly tubercles, orange-red, with small acid seeds. The plant contains a milky acrid juice. It is a native of tropical America, the West Indies, and Mexico.
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Fernanda Romagnoli



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PostSubject: Fernanda Romagnoli   Tue Oct 12, 2010 8:06 pm

Seed Dispersal

Seeds need to be dispersed away from the parent plant. After the fertilization occures the seed need to be attached to their parent plant to germinate in it and develop into a new young plant. If the young plant remains close to its parent they compete for living resources such as light energy, water and carbon dioxide.

1- Wind:
Seeds dispersed by the wind must be light and small in order to be carried by the wind. Plants have developed a number of different adaptations either to help the seeds be released. Such adaptations usually involve hairs or outgrowths which increase the surface area to catch the wind.

2- Animal: Animals of all sorts and sizes help plants to disperse their seeds. The method they use depends on the type of seed which may look attractive to animal by the brightly-colored and sweet-tasting. When animals take fruits or seeds for food, they act as transporters of the plant's seeds.
Sometimes, the plants make use of animals to carry their seeds without giving them any reward.

3-By explosion mechanism: When the carpel splits and twists, ejecting the seeds.

Example: Wind dispersal

Tumbleweed is the above-ground part of a plant that, once mature and dry, comes apart from the root and tumbles away in the wind. Usually, the tumbleweed is the entire plant apart from the roots, but in a few species it is a flower cluster. The tumbleweed habit is most common in desert plants. The tumbleweed is a seeds and spores.
It does this by scattering the in a wet location. Tumbleweed is a prolific seeder and rapid seed germination and seedling establishment occurs after only a brief and limited rainy season



Last edited by Fernanda Romagnoli on Tue Oct 12, 2010 8:17 pm; edited 1 time in total
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isidora prado



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PostSubject: isidora prado   Tue Oct 12, 2010 8:13 pm

Dispersals of seeds and fruits:

Plants need to be displaced away from their parents (because if not they will have to compete with the parent for resources). Plants adapt in different ways to be able to displace and they can displace by the following ways:

1- Wind: some plants have a specific type of anatomy that is adapted to bee able to displace. Examples: Dandelion (has a pappus) and Sycamore (has two wings formed from fused carpels). This characteristic makes the seeds displace easier with the wind.

2- Water: some plants seeds are waterproof and are able to float, so the seed falls from the plant to the water and the seed fertilizes with another plant. Example: Coconut (has a fibrous ovary wall that allows the fruit float in the water)

3- Animals: some plants-fruits are tasty and eye-catching to animals, so they eat them and the animals do not digest the little seeds so they come out on their wastes unharmed and surrounded by fertilizer. Examples: apples, avens, plum)

4- By an explosive mechanism: Some fruits suddenly burst open and throws seeds everywhere. Examples: lupin, pease, gorse.


Example of a seed:
Sunflower (Helianthus annuus):

At the center there is a disk of flowers in a pattern of spirals. It has a rough –hairy on the leaf; this helps animals not to eat the flower and also to keep water. They also attract butterflies because of their colours and their wide petals. So this flower seeds are mainly dispersed by the wind and by animals.


This is a very beautiful and colourful flower. The sun flower is the largest family of vascular plants. The family has more than 22,750 species. It is native to the Central Americas, Mexico. This plant has a very important use: the Sunflower oil (a healthy vegetable oil). Sunflower is an important agricultural crop for US producers in the Dakotas, Texas.


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vicente.sepulveda



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PostSubject: Re: Seed Dispersal   Tue Oct 12, 2010 10:05 pm

Wind: Some seeds are adapted to wind conditions which blown are blown up and rich long distances (Mostly).

Water: Some seed are waterproof and have the ability to float on water.

Animals: majority the seed resists to digestive juices, and then the seeds are removed in form of waste.

Explosive Mechanism: Some fruits, plants suddenly “expel” the seeds to the atmosphere.

Acer Ruburum (red maple):

Maple fruits are winged, two-seeded samaras. They spin like helicopters as they fall from the tree, providing a longer time for dispersal by wind and a better efficiency.

Is one of the most common and widespread deciduous trees of northern South America, at maturity it often attains a height of around 15 m (50 ft). It is aptly named as its flowers, petioles, twigs and seeds are all red. Among these features, however, it is best known for its brilliant deep scarlet foliage in autumn.

http://de.wikipedia.org/w/index.php?title=Datei:Acer_rubrum_001.jpg&filetimestamp=20071001185141
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j.bofill
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PostSubject: dispersals of seeds and fruits   Wed Oct 13, 2010 1:02 am

1. WIND: Wind dispersal can take on one of two primary forms: seeds can float on the breeze or alternatively, they can flutter to the ground.
2. WATER: Fruits which float such as those of the water lily and the coconut palm are carried by water.
3. ANIMAL: Fleshy edible fruit, where the flesh is consumed and the seed passed out or discarded at another location. Sticky or clinging fruit or seeds which attached themselves to passing animals, to be dislodged at another location.

EXAMPLE: ANIMAL DISPERSAL black berry

Some plants have juicy fruit that animals like to eat like blackberries . Animals eat the Berries but only the juicy part is digested. The stones and pips pass through the animal's digestive system and are excreted to form new plants. This can be far away from the parent plant. Birds also like to eat fruit and they help to disperse seeds to other areas through their droppings.
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beleen esquiveel



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PostSubject: Re: Seed Dispersal   Wed Oct 13, 2010 7:21 pm

1. Gravity: the effect of gravity on heavier fruits causes them to fall from the plant when ripe. Fruits exhibiting this type of dispersal include apples, coconuts and passionfruit and those with harder shells often roll away from the plant to gain further distance.

2. Wind: wind dispersal can take on one of two primary forms: seeds can float on the breeze or alternatively, they can flutter to the ground.

3. Water: seeds can travel for extremely long distances, depending on the specific mode of water dispersal.

4. Dispersal by animals: seeds can be transported on the outside of vertebrate animals, a process known as epizoochory. Plant species transported externally by animals can have a variety of adaptations for dispersal, including adhesive mucus, and a variety of hooks, spines and barbs.

Example of a seed:
Bur: a seed or dry fruit in which the seeds bear hooks or teeth which attach themselves to fur or clothing of passing animals or people. The hooks or teeth can be irritants and very hard to get off of clothing, such as wool or cotton. It was the inspiration for Velcro.

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Francesca Domic



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PostSubject: Re: Seed Dispersal   Wed Oct 13, 2010 8:58 pm

MECHANISMS OF SEED DISPERSAL:
1. Wind: wind dispersal can make two forms: the seed can go smoothly with the breeze, or the wind can make the seed fall down hardly to the ground.
2. Animals: seeds can be transported at the outside or inside of the animal, depending on the adaptation of each animal to carry them. The most important thing is that the fruit has to be attractive to the animal, to caught it attention and bring it near the plant to start the seed dispersal.
3. Water: by this mechanism of dispersal the seed had some special abilities to carry out this like, being waterproof, having the ability to float (etc); and of course by water dispersal the seed can travel long distances.
4. By explosive mechanism: some fruits suddenly burst open and throws seeds everywhere.

EXAMPLE OF SEED DISPERSAL
The flower of the peach tree
The flower peach has very attractive structure (adaptated to help the bees to make the dispersal more effectively) and colour. The flower has a sticky and sweet polen, to the bees, that will stick to their small feet and keep traveling through all the parts they go leaving small amounts of the seeds ready for the germinantion.
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eccle



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PostSubject: seed   Wed Oct 13, 2010 10:20 pm

Seed dispersal is very important for the continuality of plants. When seeds do not disperse and fall very near the plant, those plants will grow very near and this will be bad for them, because they will have to share nutrients. But if seeds are dispersed, plants may grow alone and not share essential nutrients.


Parachute method

Another way of seed dispersal is the Parachute method, this include seeds or achenes (one-seeded fruits) with an elevated, umbrella-like crown of intricately-branched hairs at the top, often produced in globose heads or puff-like clusters. The slightest gust of wind catches the elaborate crown of plumose hairs, raising and propelling the seed into the air like a parachute. This is the classic mechanism of dispersal for the Eurasian dandelion (Taraxacum officinale) and includes numerous weedy and native members of the Sunflower Family (Asteraceae). A giant Eurasian version of the dandelion called salsify or goat's beard (Tragopogon dubius), is one of the most successful wind-travelers in North America. Its seeds have literally blown across mountain ranges, colonizing vast fields of open land.
In some parachutes, the crown of silky hairs arises directly from the top of the seed (not on an umbrella-like stalk). Again, the Sunflower Family (world's largest plant family with about 24,000 described species) contains many weedy representatives with this type of parachute seed.







Eccle
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matiasnoguera



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PostSubject: Re: Seed Dispersal   Wed Oct 13, 2010 11:13 pm

Plants need disperse to live and to live a legacy. There are different types of dispersement: Wind dispersement, explosive dispersement, water and animal dispersement

Many plants produce fruits which animals such as birds and mammals eat.
In the autumn blackberries are a common sight in British woodlands and hedgerows. The berries are eaten by birds such as blackbirds and pigeons. Mice, deer and even foxes eat also eat them.
The small hard seed is hidden inside the fruit and passes through the gut of the animal as it can not be digested. The seeds are therefore expelled in the droppings of the animal. Some seeds dispersed in this way cannot germinate unless they have passed through the digestive system of an animal.

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Felipe Garrido



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PostSubject: Seed Dispersal   Wed Oct 13, 2010 11:54 pm

There are several ways in which seeds can be dispersed:

1) by Wind: a breeze can take the plants' seeds and disperse them.

2) by Water: some waterproof seeds are able to float in water to be transported.

3) by an Explosive Mechanism: plants open explosively, throwing away all of the seeds they contained.

4) by Living Courier (animals): the seeds come in a specific way (attractive form and colours) to be transported by animals. They can be transported by "getting grabbed" to the animal and then the animal disperses it by taking the seeds off or they can be consumed by the animal and then excreted to produce dispersion.



Ecballium elaterium:
The ecballium elaterium (most known as the squirting cucumber or exploding cucumber) is a plant which belongs to the cucumber family. It is used for herbal medicine. This plant has crawling stems, very thick and hairy triangular shaped leaves and yellow flowers. It has an ovoid fruit, supported by a peduncle. When the fruit is ripe, even the smallest touch can cause the fruit to explode due to hydrostatic pressure. This explosion causes the seeds to be dispersed (so we can say that the method used is the explosive mechanism). The explosion can cause the seeds to reach a distance of 3 metres of distance. Even though the plant is used in herbalism, all of the plant is toxic because it contains substances which have a laxative effect.
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josefina.gomez



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PostSubject: Re: Seed Dispersal   Thu Oct 14, 2010 3:43 pm

Plants need to disperse their seeds away from themselves to stop overcrowding and create new plants. These plants produce fruits that enable them to be dispersed in many different ways.
• By wind: Some plants are adapted to catch the wind and being blown away such as the sycamore and the dandelion.
• By animals: Lots of fruits are tasty to animals so when an animal eats these, the seeds are not digested and pass through the animal, unharmed and surrounded by fertilisers like the blackberries and plum.
• By water: Some fruits are waterproof and can float in water for example the cocunut.
• By an explosive mechanism: Some fruits suddenly burst open throwing their seeds in all directions such as the lupin.
• By catching a lift: Some fruits have tiny hooks on them that catch on passing animals and get carried away.
• Drop and roll: Some trees have casings that split open and roll away when they fall to the ground. An example of this is the horse chesnut.

The sunflower:
Sunflowers are large flowers that contain an enormous amount of seeds. These seeds can be dispersed by four ways: wind, animals, catching a lift and water. When they are dispersed by wind it is because most of them form structures similar to tiny parachutes. These have a pappus (upper part of parachute that is extremely lightweihgt), a stem and the bottom of the stem which is actually the seed or fruit. When wind is blown hard enough it can catch the pappus and lift the seed from the plant and into the air current until the wind dies down and the seed and pappus land in a new location. Some types of sunflower like the “large sunflowers” do not form a pappus but instead produce edible seeds that are pecked away by birds that carry them away or cause them to fall. Another type of flower in sunflower family known as the “notorious cockelbur” has a seed structure so they can get caught in clothing or fur. Eventually these will fall of the fur or clothing and will land in a new location. Finally it can be dispersed by water, this happens when they accidently land in water, such as river and streams and are carried by the current until it finds a new location. This is considered the less effective way of dispersal for the sunflower.
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vicentem
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PostSubject: Re: Seed Dispersal   Thu Oct 14, 2010 4:51 pm

Here are different way seeds can be dispersed...

1.) After the seeds have formed, they are usually scattered, sometimes far from where they were produced. The scattering of the seeds is called "seed dispersal".

2.) Water. Water can disperse seeds that fall into oceans and rivers.

3.) Wind. Wind disperses lightweight seeds that often have structures to catch the wind.

4.) Some plants eject their seeds, and the force scatters the seeds in many directions.

5.) When seeds are mature, the scales open. The wind shakes the seeds out of the cone and carries them away. Only a few seeds will land in suitable places and grow into new plants.

6.) Fruits are the means by which angiosperm seeds are dispersed. Animals that eat fruits help to disperse their seeds.



EXAMPLE OF SEED DISPERSAL:

Parachutes

An individual parachute of western salsify (Tragopogon dubius) showing an umbrella-like, plumose crown of hairs (pappus) above a slender one-seeded fruit (called an achene). These fragile units can become airborne with the slightest gust of wind, and can literally sail across valleys and over mountain slopes.

Western salsify or goatsbeard (Tragopogon dubius) showing dense, puff-like cluster of numerous parachute seeds (one-seeded achenes). Each achene has an umbrella-like crown of plumose hairs and may literally be carried into the atmosphere by strong ascending air currents.

A population explosion of western salsify(Tragopogon dubius) near Mono Lake, on the east side of the Sierra Nevada of Central California. This ubiquitous species is actually native to Europe and Asia.
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carlos.munoz



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PostSubject: Re: Seed Dispersal   Thu Oct 14, 2010 7:05 pm

1. By wind: Some fruits are developed to be blown by the wind

2. By water: This occurs when plants living in the water or very near it, can fall and float in the water and be carried away.

3. By animals: The most common way of doing this is that the animals ingest the seed, which is then excreted far away from the initial point.

Example: wind dispersal Dandelion

After flowering is finished, the dandelion flower head dries out for a day or two. The dried petals and stamens drop off, the bracts reflex, and the parachute ball opens into a full sphere. Finally, the seed-bearing parachutes expand and lift out of it. The parachute drops off the achene when it strikes an obstacle. After the seed is released, the parachutes lose their feathered structure and take on a fuzzy, cotton-like appearance, often called dandelion snow.

http://en.wikipedia.org/wiki/Dandelion#Seed_dispersal
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cata.lagos



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PostSubject: Seed Dispersal Catalina Lagos 1D def7   Thu Oct 14, 2010 8:19 pm

To make themselves space in the world, plants disperse their seeds. There are many ways they can do this,normally it is choosen the one most efficient in the environment. Some ways it can be dispersed are:
By wind: There are some fruits that adapted themselves to catch the wind and use it for their own benefit. For example the dandelion uses the wind to throw the seeds to a place far away.
By explosive mechanism: there are fruits that can function by its own. An important example will be the lupin a fruit that suddenly burst throwing their seeds in many directiones at the same time.
By water: Some seeds are resistable to water because they want to travel throw the water until reaching a straight land.
By animals: As many others, fruits are tasty to animals. This will make a easier travel for them because their eaten and not digested. This means no harm has been made to the seed, so the seed passes through the animal and thrown into any land with an extra fertiliser surrounding it.

Dandelion
The leaves are 5–25 cm long or longer, simple and basal, entire or lobed, forming a rosette above the central taproot. The flower heads are yellow to orange colored, and are open in the daytime but closed at night. The heads are borne singly on a hollow stem that rises 1–10 cm or more above the leaves and exudes a milky sap when broken. A rosette may produce several flowering stems at a time. The flower heads are 2–5 cm in diameter and consists entirely of ray florets. Each achene is attached to a pappus of fine hairs, which enable wind-aided dispersal over long distances.
The flower head is surrounded by sepals in two series. The inner sepals are erect until the seeds mature, then flex downward to allow the seeds to disperse; the outer bracts are always reflexed downward. Some species drop the "parachute" from the achenes; the hair-like parachutes are called pappus, and they are modified sepals. Between the pappus and the achene, there is a stalk called a beak, which elongates as the fruit matures. The beak breaks off from the achene quite easily, separating the seed from the parachute.
Taraxacum are seed dispersed ruderals that rapidly colonize disturbed soil, especially the Common dandelion which has been introduced over much of the temperate world. After flowering is finished, the dandelion flower head dries out for a day or two. The dried petals and stamens drop off, the bracts reflex , and the parachute ball opens into a full sphere. Finally, the seed-bearing parachutes expand and lift out of it. The parachute drops off the achene when it strikes an obstacle. After the seed is released, the parachutes lose their feathered structure and take on a fuzzy, cotton-like appearance, often called "dandelion snow".
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john gray



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PostSubject: Re: Seed Dispersal   Thu Oct 14, 2010 9:52 pm


wind: also wind make seed dispersal occur by transpoting through the air the seeds. Its the most important way.

water: also water make seed travel very long distances.

gravity:one way of making seed dispersal is by gravity this affects all diffrent types of plants mostly big fruits which make them fall when ripe.

dispersal by animals: also seed can travel by animals mainly by vertebrates this is known as epizoochory.

EXAMPLE OF SEED DISPERSAL: ANIMAL DISPERSAL

ACORN: Acorns, are too heavy for wind dispersal, and so require other ways to spread. Oaks therefore depend on biological seed dispersal agents to move the acorns beyond the mother tree and into a suitable area for germination (including access to adequate water, sunlight and soil nutrients) ideally a minimum of 20–30 m from the parent tree
Many animals eat unripe acorns on the tree or ripe acorns from the ground, with no reproductive benefit to the oak. But, some animals serve as seed dispersal agents. Jays and squirrels that scatter-hoard acorns in caches for future use, effectively plant acorns in a variety of locations in which it is possible for them to germinate and thrive.

Although jays and squirrels retain remarkably large mental maps of cache locations and return to consume them, the odd acorn may be lost, or a jay or squirrel may die before consuming all of its stores. A small number of acorns manage to germinate and survive, producing the next generation of oaks.

Scatter-hoarding behavior depends on jays and squirrels associating with plants that provide good packets of food that are nutritionally valuable, but not too big for the dispersal agent to handle. The beak sizes of jays determine how large acorns may get before jays ignore them.

Acorns germinate on different schedules, depending on their place in the oak family. Once acorns sprout, they are less nutritious, as the seed tissue converts to the indigestible lignins that form the root.

JOHN GRAY 1C





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trini.zuazo



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PostSubject: seed dispersion   Thu Oct 14, 2010 10:17 pm

Until recently taxonomists recognized more than 50 species in Canna, but that number has now been reduced to ten (P. J. M. Maas 1985; P. J. M. Maas and H. Maas 1988) based mainly on new concepts of biogeographical history, the extent of hybridization during cultivation, and the plasticity of morphological features, especially in the highly polymorphic species C. indica.

Little has been published regarding pollination of these plants . The two North American species with pale yellow flowers, Canna glauca and C. flaccida, flower at dusk and may be pollinated by hawkmoths. Several neotropical species with bright red or orange flowers are hummingbird-pollinated. Nectar, which accumulates at the base of the floral tube , is the apparent reward in all cases. Pollen is shed from the bisporangiate anther onto the adjacent style before the flower opens (secondary pollen presentation), which usually results in self-pollination ; thus, greenhouse-grown plants readily set seed. The large seed size and lack of reward for potential animal dispersal agents suggests that seeds are dispersed by gravity and water. Seeds can germinate and produce reproductive shoots in a single growing season .
i cant put a picture!
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matias.lafrentz



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PostSubject: Re: Seed Dispersal   Thu Oct 14, 2010 10:30 pm

Is the movement and and transport of seeds away from parent plant. Because of their limited mobility they usually rely of diferent factors, such us wind, water, animals, etc. The seeds once dropped are dispersed around the ground or moved into other flowers. With this process plants and flowers grow.

by Wind: the wind can take the plants seeds and dsperse them 1) by Wind: a breeze can take the plants' seeds and disperse them.


by Water: some seeds can float and be transported by the water.


by an Explosive Mechanism: plants open explosively, by these they throw all the maximun seed they can.


matias lafrentz

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Anto Arroyo



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PostSubject: Re: Seed Dispersal   Thu Oct 14, 2010 11:15 pm

Plants need to disperse the seed from themselves to prevent an overcrowding. There are several ways in which plants can disperse their seeds:

1. Wind: some plants are adapted to catch the wind easily and to be blown away by it. Some examples are: the sycamore and the dandelion.
2. Water: Some plants are waterproof and float, making it easy for them to transport through water without having any damage.
3. Animals: Some plants have tiny hooks on them, so that when an animal passes next to it, it sticks to the animal and is transported by the animal until it falls off. Another way to be transported by animals is when the animal eats it, the seeds are not digested, and when the animal excretes, the seed is unharmed.
4. Explosive mechanism: This happens when plants burst open explosively, throwing the seeds far away.

Coconut palm trees
The coconut palm tree is a member of the arecaceae family. The coconut palm tree lives on areas with a lot of sunlight, humidity and rain. To disperse their seeds, coconut trees use water. The coconut is a very thick and waterproof layer that protects the seed while it is on water, it also floats, so the coconut palm tree has the perfect adaptations to be able to disperse its seeds by water.



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Trinidad Torres



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Join date : 2010-07-30

PostSubject: SEED DISPERSAL   Fri Oct 15, 2010 12:04 am

Seeds need to be dispersed away from the parent plant so it does not compete for resources such as light energy, water and carbon dioxide. The separation methods are the following:
WIND: blows the seeds away by the breeze
WATER: transport the seed which manly all float
ANIMALS: some animals texture help dispersing because seeds stuck to them and are carried away, or by excretion when seeds are not digested by the body
EXPLOSIVE MECHANISM: when the plant split and twists so the seeds are ejected

MY SEED:
Milkweed from the Asclepias flower

The seed milkweed is named like this because of it's milky juice which is toxic. The flower Asclepias is named that way in order to honour a God because of it's extraordinary folk-medicinal use of healing. This flower produces it's seed in follicles which are arranged in overlapping rows that have white silky filament-like hairs that are known as pappus. These follicles are ripen and splited open and the seeds are carried away by the wind.

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matias kalm



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PostSubject: Re: Seed Dispersal   Sat Oct 16, 2010 3:25 pm



The seed of the plants must be desplaced because if it would not do that it will be a lot of population of the same kind of plant in a small area which will produce that they have less nutrients. This can be made by different methods:
1. Wind: This happens naturally when the wind blows out an almond from the tree were its hanging, here the seed often falls to the ground near the tree because the wind doesn’t have the strength to blow the seed so far.
2. Water: the seed of some plants are carried away by water. This is mainly when the plant’s fruit can float. Later they can germinated in new places
3. Animals: some seeds are made to get tangled in animal fur or feathers and others to eat them. All of these so that the seeds can be carried away from their plants, so they germinate in new places.

Example: Bur Macro

Bur macro: This fruit attatches to animal fur via the hooks on its surface to improve distribution.

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carina vera



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PostSubject: Re: Seed Dispersal   Mon Oct 18, 2010 8:14 pm

Plants need to spread their seeds to be able to realize one of the living thing's basic need: reproduction.
There are many different ways for seed dispersal to occur, and throug time, plants have adapted to nature for their seeds to disperse.
1. Wind: some plant's main seed disperser is the wind. The seeds have features that allow the wind to catch them easily, and blow them away.
2. Water: is another important transporter and provider for plants. Some plants have their seeds in a shell which can float or in a waterproof shell.
3. Living courier: when an animal/human passes by a plant, the seed may attach to the fur or skin, and may luckily be carried away a distance from the original plant.
4. Explosive mechanism: some fruits are very sensitive to touch, and explode when in contact with something, exploding and realising seeds in all directions.
5. Animals: seeds may be gastric juice tolerant, and pass through the animal's digestive system, and come out.

My plant: South African Fynbos.
South African Fynbos is actually a plant specie that depends on ants for seed dispersal. Seed dispersal by ants is called myrmecochorous. The seeds in these kinds of plants has an attachment called elaiosome, which attracts ants. Ants carry these seeds into their colonies, feed the elaiosome to their larvae and discard the intact seed in an underground chamber. This is very useful for the seeds because Fynbos plants are constantly burnt down by fires, which burn the original plant down, giving back all the nutrients i contained to the earth. By myrmecochorous, the seeds are protected by fire when taken underground, and by recieving the nutrients of the old plant, have more chances of growing.
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pedro grove



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Join date : 2010-07-30

PostSubject: seed dispersal   Mon Oct 18, 2010 8:20 pm

Seed Dispersal

Seed dispersal is the movement or transport of seeds away from the parent plant so then the plant can expand or spread its range when a seed is carried to a new environment suitable for growth.


Seed dispersal of the almond

The almond is the seed of the tree called by the same name. The seed has a thin cover and we as humans eat it. This seed can be dispersed in several ways:

1) By wind: This happens naturally when the wind blows out an almond from the tree were its hanging, here the seed often falls to the ground near the tree because the wind doesn’t have the strength to blow the seed so far.

2) By water: This case is very rare and only occurs when the tree is near a river. It happens when the seed falls into the river and deposit on another part were the river leaves it. Most of the time the seed end far apart the tree and near the river were it had came from.

3) By animals: This happens though ingestion. This means the animal eats the seed and afterward it throws it away as waste and the seed get out. By this way of dispersal the seed can be placed near or away from the original tree, it depends were the animal leaves his wastes, but what is most common is that the seed is placed far apart from the tree.


PEDRO GROVE 1E

alien jocolor afro lol!
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