important bits in biology for 10 class in respiration
Answers
Question 1
Why do organisms need food?
Answer
Organisms need food for obtaining energy to perform the vital functions.
Question 2
What is a respiratory substrate?
Answer
The substance used by the cell to derive energy is called a respiratory substrate
Question 3
How does food yield energy?
Answer
Food is broken energy in the form of ATP.
Question 5
Name a few respiratory substrates. Which of them is most commonly used?
Answer
Carbohydrates, fats, proteins are some of the respiratory substrate. The most commonly used of them is glucose, a carbohydrate.
Question 6
Give the general equation for respiration?
Answer
C6H12O6+6O2--> 6CO2+6H2O+38ATP
Question 7
What are the stages of respiration?
Answer
Respiration takes place in the following stages:
External respiration or gaseous exchange: The exchange of gases between the environment and the body is called external respiration or gaseous exchange.
Internal respiration: The bio-chemical processes involved in respiration which break down the substrate to release energy take place in the tissues within the cells of an organism. Thus, this is also called the cellular or tissue respiration.
Question 8
What is the respiratory surface?
Answer
The area where the gaseous exchange takes place is called the respiratory surface.
Question 9
What are the characteristics of an ideal respiratory surface?
Answer
The respiration surface should have the following characteristics:
a) It should be permeable to the gases.
b)It should be thin (1mm or less) to allow effective diffusion.
c) It should be richly supplied with blood vessels or bodily fluids to allow maximum uptake of oxygen in minimum time.
Question 10
How does gaseous exchange take place in the lower plants?
Answer
In lower plants exchange of gases takes place through the general body surface as they are not highly modified or specialized.
Question 11
Which part of a plant is involved in the gaseous exchange?
Answer
The entire plant is involved in gaseous exchange- leaves (stomata), stem (lenticels) and general surface of the roots.
Question 12 How does gaseous exchange take place in the leaves?
Answer The leaves have openings called the stomata which are generally on the lower surface of the leaves. It is through the stomata that the gases and water vapour diffuse in and out easily. The oxygen diffuses in through the stomata and then enters the leaf cells.
Similarly, the carbon dioxide produced by the leaf cells diffuses out through the stomata.
Question 13
What are lenticels?
Answer
In woody stems, the entire surface is covered by dark which is impervious to gases or water.
However, there are certain openings or pores in the layer of bark. These are called the lenticels. They are visible more raised then the general surface of the stem. At the base of the lenticels are loosely arranged cells which allow the diffused gases to pass in and out.
Question 14
What are pneumatophores?
Answer
Plants which grow in salty water show specialized roots called the on. These are roots growing out of the surface of water with numerous pores on their surface.
Question 15
How does exchange of gases take place in fish?
Answer
Fish have specialized organs called the gills for exchange of gases.