The atrioventricular apertures are guarded by valves. There are valves in the aorta and pulmonary
artery also.
The right side of heart receives blood from body and sends to lungs.
The left side of the body receives blood from lungs and send it to body parts.
The arteries carry oxygenated blood except pulmonary artery. The veins carry deoxygenated blood
except pulmonary veins.
One contraction and relaxation of heart is called cardiac cycle.
If the blood goes to heart only once before it reaches all the body parts. It is called single circulation.
If it goes twice it is called double circulation.
Vitamin K deficiency leads to delayed coagulation of blood.
Plants absorb soil water through roots by the process of osmosis.
Water travels through xylem vessels and food material travels through phloem tissues.
There is a relation between tranportation and transpiration in plants.
Biologists studied about phloem tubes with the help of aphids.
Improve your learning
1. What is transport system? How does this help the organism?
2. What is the relationship between blood and plasma?
3. Which type of blood vessels carry blood away from the heart?
4. What are the three main types of blood vessels in the body?
5. Which is the largest artery in the body? Why is it the largest ?
6. Which blood vessel carries blood for oxidation?
7. Name the structures which are present in veins and lymph ducts and absent in arteries.
8. What is the use of platelets?
9. Write differences between (AS1)
a) systole - diastole b) veins - arteries c) xylem - phloem
10. Explain the way how the plants absorb water from soil ?
11. What is root pressure? How it is useful to the plant?
12. Phloem is a food source for some animals. How can you justify this statement?
13. Read the given para and name the parts of the heart.
We have observed that the heart is divided into four chambers by muscular structure. Any
structure that divides two chambers is known as septum. Now let us try to name the septa present
in the heart.
a) The septum that divides the two atria can be named as _____________