Science4Geeks

Thursday, 19 January 2012

Seed Dispersal

Hello there readers! It's been a while since my last update. So I've been teaching my students "Reproduction in Flowering Plants" for a couple of weeks now and I decided to post this sub-topic on "Seed Dispersal". Ready to learn yet? I think you might find this video pretty interesting :D Watch it till the end on how different seeds are dispersed. It's AMAZING how these different seeds have different structures or designs to help them move. B) But before you watch the video, may I suggest you read this brief lesson on seed dispersal? :)

Wait...do you even know the term seed dispersal? It means spreading of seeds from one place to another. So shall I start my lesson now? :) Plant seeds can be dispersed in a number of different ways according to its features.

Some seeds such as dandelion seeds and sycamore seeds are light and have a wing- or parachute-like structures to help them float or spin in the air. This method is known as wind dispersal.

Another way is water dispersal such as a coconut fruit and nipah fruit which has a fibrous husk that traps air and allows it to float on water. Some plants that grow near water may also transport their seeds by the moving water.

In some plants such as bauhinia and saga, the seeds are in pods and can self dispersed. When the pods become dry, they split open and the seeds are scattered. Few plants like rubber seeds and squirting cucumber, they are designed to explode and scatter the seeds further away from the parent plant. WHAT?! SEEDS CAN EXPLODE BY THEMSELVES?? Yeah...see it to believe it! Watch the video posted below later. Getting more excited already? There's more...

Many plants can also use the animals to move seeds around. These plants may have hooks or spikes on them which can cling to the animal's fur before this animal drops them off elsewhere. For examples, burdock seeds and fruits of a love grass. On the other hand, the plants might have tasty, juicy, fleshy fruits with seeds which can be carried away and eaten by the animals such as tomatoes, watermelon, mangoes, papayas and so on. So that's animal dispersal.

It is better for the seeds to be dispersed some distance away from the parent plant. This will prevent overcrowding and competition for nutrients, water and light.

Alright then. Enjoy watching this video! Happy learning~ ;D

Sunday, 18 September 2011

Photosynthesis

Hi there readers! I promised my students that I'm gonna upload this video that i presented in class this week. They love this and you might like it too :)

But before that, I'm gonna give you a brief introduction to a plant process called photosynthesis. "Photo" is a Greek word for "light," and "synthesis" means "to combine." We all get our energy from the food we eat which we get directly or indirectly from plants. How about plants?

They use this process to make their own food. Photosynthesis can only occurs in the green parts of the plant. Leaves have tiny like structures called chloroplasts which contain a green pigment known as chlorophyll. The function of chlorophyll is to absorb sunlight and takes the carbon dioxide and the water, and turns them into sugar (glucose) and oxygen. The glucose provides the energy for the plant and the glucose can be converted into starch as food to be stored inside the plant. The oxygen which is the by product of photosynthesis will be released to the air through tiny pores called stomata found underside of the leaves.

So, photosynthesis can be defined as a process whereby green plants make food (glucose) using the raw materials carbon dioxide and water in the presence of sunlight. This process also releases oxygen. Here's the word equation for photosynthesis:

Plants and animals (including us human) need each other to survive. We breathe out carbon dioxide which is needed for the plant during photosynthesis. Plants photosynthesize to make food and oxygen that we need. Other than oxygen used for respiration in living things, photosynthesis is also important whereby the oxygen released is used to purify the air by removing carbon dioxide in the atmosphere which can cause global warming.

Ok ok...enough already. Now it's time for you to enjoy the video. :))

Here are the lyrics for you to sing along! You might as well learn the lyrics...It's a fun way to learn! :D

If you want to know,
How a plant grows,
It takes water, air and sunlight,
and makes cellulose...

Every plant can do this,
Fundamental process,
and we can call this,
Photosynthesis!

Unlike me and you,
Plants need CO2,
and they make oxygen,
That stops us turning blue...

Every plant can do this,
Fundamental process,
and we can call this,
Photosynthesis!

It's a miracle,
How all the chlorophyll,
Captures sunlight in the leaves
of the plants and the trees...

A plant of any size,
Can do this if it tries,
But we're not green so we can't
Photosynthesize...

Every plant can do this,

Fundamental process,
and we can call this,
Photosynthesis!

It's a miracle,
How all the chlorophyll,
Captures sunlight in the leaves
of the plants and the trees...

Every plant can do this,

Fundamental process,
and we can call this,
Photosynthesis!

Every plant can do this,
Fundamental process,
and we can call this,
Pho-to-syn-the-sis! (photosynthesis)

Click the link below to test your knowledge of Photosynthesis!

http://www.growingthenextgeneration.com/agrium-games/quiz/index.htm

Friday, 26 August 2011

Plant and Animal Cells

CELL

Cell is a small unit that makes up living organisms. Living organisms may exist as one cell (unicellular) such as amoeba (an animal) and euglena (a plant) or many cells (multicellular) such as man, cat and rose.

PLANT AND ANIMAL CELLS