U 4: PLANTS
 | "Green planet = clean planet" |
Plants are living things, and as all living things they carry out the three main life functions of NUTRITION, REPRODUCCIÓN e INTERACCIÓN.
In this unit we are going to deal with the living functions, as well as with some related natural matters towards plants and nature.
O. SOME GENERAL MATTERS ABOUT PLANTS.
Parts of the plants, function of each part, types of plants, reproduction, general uses of plants.....
Parts of the plant and functions of each part.
1. PLANTS NUTRITION AND RESPIRATION.
Plants are "producers" since plants are able to produce their own food.
A) PHOTOSYNTHESIS
It is the process by which plants TAKE water, minerals, carbon dioxide (CO2) and solar energy and PRODUCE glucose and oxygen (O2)
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VIDEO
B) RESPIRATION
 | Plants need solar energy to do the photosynthesis. So they can do the photosynthesis only during the day time. They can´t do the photosynthesis during the night time. During the night plants breathe oxygen (O2), like all living things (plants, animals ...) |
2. PLANTS REPRODUCTION.
Plants can reproduce, like all living things. Plants can reproduce in 2 different ways: sexually & asexually.
A) SEXUAL REPRODUCTION
Plants which develop flowers, or flowering plants, produce seeds through sexual reproduction.
| Flower --> fruit --> seeds |
Parts of flowers and pollination
B) ASEXUAL REPRODUCTION
There are different types of asexual reproduction:
1. Asexually reproduction by spores.
Non-flowering plants don´t produce seeds and reproduce asexually using spores.
* Spore: It is a cell that grow inside a spore case or capsule.
* Examples of plants that reproduce by spores: ferns and moses.
2. Asexually reproduction by stolons, and by rhizomes.
Some plants grow special horizontal stems called stolons. When stolons reach the grown, new roots start to grow, and a new plant develops.
Other plants grow underground roots horizontally, and from the rhizome a new plant develops too.
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3. Asexual reproduction with tubers and with bulbs.
3. PLANTS INTERACTION.
As any other living things (plant & animals), plants also have this third life or vital INTERACTION FUNCTION. Plants also have sensibity.
Obviously plants interaction is different to animals interaction, but plants also react to what happens around them.
- Plants perceive the weather conditions: if it is raining and the soil is wet, or it it is very dry; if it´s sunny or cloudy for a long period, it it is cold or hot, the wind...
- They can also perceive if they life on one kind or other kind of soil.
- They can perceive what animals do to them, or if they are damaged....
Some examples of interaction:
- Pollination of plants by insects.
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Butterfly pollination |
The hummingbird is the smallest bird on the world. It is even smaller than some insects... They can fly without moving away, like a helicopter..., so they can take the pollen by flying like this. |
- Photosynthesys: It takes place only when there is sunlight.
- Phototropism: Plants need sunlight to live, so if they are in a dark place, plants branches grow or move slowly towards sunlight, to look for it, to get more sunlight.
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Sunflower turn their head or big flower looking for the direct sunlight along each day. |
- Hydrotropism: Plants also need water to live, so plants roots grow or move slowly towards water, to look for water.
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- Geotropism: They are all roots tropism or movements, to look for water, a better soil, to avoid rocks, ...
4. OTHER NATURE ISSUES RELATED TO PLANTS.
An ecosystem is formed by all living things and non-living things (environment) that stay together in a natural place and the relationships that there are among them.
Video Ecosystems and food chain
Environmental conservation
4.2. GLOBAL WARMING
Greenhouse effect
| Garden Greenhouse | Earth greenhouse effect |
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Consecuencies of global warming
