| Autotrophic nutrition | Heterotrophic nutrition |
| (i) Food is synthesised from simple inorganic raw materials such as CO2 and water. | (i) Food is obtained directly or indirectly from autotrophs. This food is broken down with the help of enzymes. |
| (ii) Presence of green pigment (chlorophyll) is necessary | (ii) No pigment is required in this type of nutrition. |
| (iii)Food is generally prepared during day time. | (iii) Food can be prepared at all times |
| (iv) All green plants and some bacteria have this type of nutrition. | (iv) All animals and fungi have this type of nutrition. |
In highly organised plants, there are two different types of conducting tissues - xylem and phloem. Xylem conducts water and minerals obtained from the soil (via roots) to the rest of the plant. Phloem transports food materials from the leaves to different parts of the plant body.
The exchange of gases takes place between the blood of the capillaries that surround the alveoli and the gases present in the alveoli. Thus, alveoli are the site for exchange of gases. The lungs get filled up with air during the process of inhalation as ribs are lifted up and diaphragm is flattened. The air that is rushed inside the lungs fills the numerous alveoli present in the lungs.
Each lung contains 300-350 million alveoli. These numerous alveoli increase the surface area for gaseous exchange making the process of respiration more efficient.
Life processes such as nutrition, respiration, transportation, excretion, etc. are essential for maintaining life.
(a) The process in plants that links light energy with chemical energy
Ans. Photosynthesis
(b) Organisms that can prepare their own food
Ans. Autotrophs
(c) The cell organelle where photosynthesis occurs
Ans. Chloroplast
(d) Cells that surround a stomatal pore
Ans. Guard cells
(e) Organisms that cannot prepare their own food
Ans. Heterotrophs
(f) An enzyme secreted from gastric glands in stomach that acts on proteins.
Ans. Pepsin
(a) Trypsin
Ans. Protein
(b) Amylase
Ans. Starch
(c) Pepsin
Ans. Protein
(d) Lipase
Ans. Fat