Plants and nutrition

I am sure that you know what a plant is. You know that they are living organisms, you can see them every where and most of them are green. Plants are members of the kingdom plantae and they include trees, flowers, grass and more. 

Plant cells are composed of rigid cell walls made of cellulose. They have a nucleus, large vacuoles filled with water, ribosomes, mitochondria and chloroplasts.

Plant cell. Wikipedia.

The three basic parts of most plants are the leaf, the stem  and the root. 

The leaf is an organ that is specialized for photosynthesis. By this process plants make their own food. It takes place in the cell chloroplasts thanks to the light energy from the Sun. Water and carbon dioxide are transformed into sugars and oxygen is released as a waste. So, leaves are mainly flat and thin in order to catch as much sunlight as possible. 

The stem is the main structure that supports leaves and flowers. Stems have vascular tissues that move water, salts and food around the plant. Xylem sap travels from the roots to the green parts of the plant and the phloem sap travels from the green parts to all the plant's cells. Some plants, like potatoes, store food in their stems.

Roots fix the plant in the ground and enables it to absorb water and mineral salts. Some plants store foods in their roots.

Plants respire too, like animals. Respiration takes place in the mitochondria. In order to carry out this process, plants absorb oxygen and get energy from sugars obtained during photosynthesis. Water and carbon dioxide are produced.

And what happen with waste products? Plants have no specialised organs for excretion. This function is carried out by the plant's entire surface. The waste products are oxygen, water and other substances like latex.

And now some activities. Please answer them as comments.

1. How do you say in Spanish: leaf, stem, root, sugar, waste, sunlight, sap? 

2. What organelles can you find in a plant cell?

3. In which organelles does photosynthesis take place?

4. What is the name of the mixture of water and mineral salts?

5. Where does the distribution of substances in plants take place?

6. Which organelles are responsible for respiration in plants?