UNIT 1: The basis of life
nd
Natural science (2 ESO)
READING ACTIVITIES
After reading the text, copy and answer the following questions into your notebook:
Remember: you must make complete sentences.
4.1. Answer these questions:
a. Do plant cells perform cellular respiration? Why?
- Yes, they do.
- It is because all cells need energy to stay alive (to perform vital functions).
Cellular respiration is the chemical reaction that provides energy to cells.
b. Why is photosynthesis an anabolic reaction?
Photosynthesis is an anabolic reaction because it makes organic matter (complex
substances) from inorganic matter (simple substances) and it requires energy (sunlight).
c. Can all the cells of a plant perform photosynthesis? Why?
No, not all the cells of a plant can perform photosynthesis. It is because to do it, cells need
chloroplasts and not all the plant’s cells have them, such as root´s cells. They are always
buried and never receive sunlight.
d. When do cells perform fermentation?
They perform fermentation when they cannot carry out cellular respiration because
they do not have oxygen.
4.2. Indicate the difference between:
a. Chemosynthesis – Photosynthesis
The difference between them is that photosynthesis has sunlight as source of energy and it
is perform by plants, algae and photosynthetic bacteria, while chemosynthesis has
chemical reactions as source of energy and it is performed only by some bacteria.
b. Anabolism – Catabolism.
The difference between them is that anabolism is the construction phase of the metabolism
in which complex substances are made from simple substance and it requires energy, while
catabolism is the destruction phase of the metabolism in which simple substances are made
from complex substances and it produces energy.