Plants

 

Plants are part of a system in which cooperation is essential is order for the plant to survive.

 

Plant Parts: Working as a Team

Plant parts work together. The roots absorb water, the stems conduct it, so the leaves can use it to make food, which the stems conduct back to the roots for storage.

The law of cooperation can be seen in that if a particular part of the system does not fulfill its role the plant will not survive.

Click here to learn more about plant parts and how plants work together  (Click here)

Photosynthesis

A process by which a plant produces its food using energy from sunlight, carbon dioxide from the air, and water from the soil.

Photo means light and synthesis means put together.

Photosynthesis is how plants use light and water to make sugar. Sugar is created in the green parts of a plant and every animal on earth depends on it. Without plants we would have no food to eat or oxygen to breath. Here is a picture to show how it happens.

 
Plants absorb a common gas called carbon dioxide, pull water up through their roots and use light to make sugar. Plants use the sugar to grow. Plants give off oxygen as a by-product. The green parts of the plant makes the sugar and oxygen.

 

Carbon dioxide + water + sunlight = sugar + oxygen

 

Parts of a Flower

Petals- petals are brightly colored to attract insects such as bees and butterflies into the flower.  Insects pick up the pollen from the flower and carry it to the next flower that they visit.  This is how insects pollinate flowers.

 

Stamen - Stamen are the male parts of the flower.  They make the pollen.  Pollen is the fine yellow powder needed to make a new plant.  Each stamen has two parts, the anther and the filament.  The anther contains the pollen and the filament holds up the anther. 

Stigma- the stigma is female part of the flower.  This is where the seeds are made.  The stigma is sticky to catch the grains of pollen.  The style is the neck that the pollen travels down to get to the Ovary. 

Ovary- in the ovary, the pollen joins the ovule and the ovules become seeds.  This process is called fertilization.

Receptacle- the Receptacle is the top of the flower stalk.  This is where the flower parts are attached.  It is often round in shape.  All the parts of the flower are attached to the receptacle.

Sepals- sepals are special kinds of leaves that form a ring around the petals.  Their job is to protect the flower while it is still a bud.  After the flower has opened, the sepals can still be seen behind the petals. All the sepals together are called the CALYX

 

 

Use this website to dissect a virtual flower CLICK HERE

 

Seed Dispersal

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     Click here to learn more about seeds

Flowering plants reproduce themselves by producing seeds. The seeds also provide the plants with a way to spread out and grow in new places, sometimes a long way from the parent. This is important because if the seeds are not dispersed, many germinating seedlings will grow very close to the parent plant. This results in competition between every one of the seedlings as well as with the parent plant. The competition is for light, space, water and nutrients. All of these are important for plants to be able to grow.

Seeds can be dispersed in a number of different ways. They may be carried by wind, water or animals. Some plants even shoot the seeds out explosively. Seed size is an important factor.

Plants like milkweed, dandelions, and cattails release seeds attached to light, parachute-like puffs that are easily carried by wind over great distances. 

The seeds of the maple, linden and ash - with their helicopter-like wings -- also drift in the wind.  Some seeds catapult into the air through expulsion.  Touch the pod-like seed containers of the jewel weed and they spring open into two halves, flinging seeds into the air.  Witchhazel and violets also disperse their seeds this way.  There are a number of seeds- like the coconut, American lotus, bladder nut and cranberry, that travel by floating on water.  Drop a few cranberries in a bowl and see how easily they float.  The berries have a waxy, waterproof covering.  Cut a berry open to find four air pockets, each containing a seed.

Animals and people help seeds get around.  Some seeds, like those of the burdock, are "Hitchhikers".  The seeds are in burrs with little hooks that cling to human clothing and the fur of animals.  Squirrels are known for their habit of burying acorns for winter food.  Acorns that the squirrels can't find later have, in effect, been planted by the squirrels.  Some fruits and seeds are eaten together by birds and animals.  The seeds have a tough, indigestible coating, and later reach the ground as waste.  Farmers' fence lines often become rows of berry bushes.  Birds sit on the fence and excrete seeds;  the seeds germinate and grow into plants.  Humans can carry seeds across continents and oceans.  Oranges originally only grew in China, cucumbers came from India, corn originated in Central and South America, and tomatoes are native to Peru.  Colonists brought seeds from their homelands both deliberately, for planting and accidentally, (in bales of hay).

 

 

Some of the largest seeds in the world come from a palm plant called the coco de mer.  The seeds can grow to be bigger than beachballs and weigh as much as 50 pounds.
 Coco de Mer fruit

Click here to play a game about seed dispersal

Watch the Magic School Bus Video - Plants a seed

Watch Magic School Bus Gets Planted

A huge thanks to Deborah in MD for all her help!!!