P-2 Animal Classification — Science STD 10 — Question

Describe the working of human blood circulatory system with the help of a suitable diagram which shows all the steps involved.

There are two similar glands P which are located on top of two similar organs Q in the human body. P are often called the emergency glands and they secrete a hormone R into the blood stream. R is secreted in large amounts when a person is frightened. It brings about temporary changes in the body which allow a lot of substance S from the liver to go into the blood to provide a lot of energy in a very short time. This helps a person to fight back or run away from the frightening situation.
What are P, Q, R and S?

Write short note: Post-disaster management.

Pine oil is used in Froth floatation.

When the branches of a plant growing in the field are pulled towards the ground and a part of them is covered with moist soil (leaving the tips of the branches exposed above the ground), then after some time new roots develop from the parts of branches buried in the soil. On cutting these branches from the parent plant, new plants are produced from the cut parts of branches which had developed roots.

1. What is this method of propagation of plants known as?
2. What type of branches should a plant have to be able to be propagated by this method?
3. Name any two plants which are grown for their flowers and propagated by this method.
4. Name any two plants which are grown for their fruits and propagated by this method.
5. Name one plant which gets propagated by this method naturally by forming runners (soft horizontal stems running above the ground).

Aluminium oxide is called an amphoteric oxide.

With a neat labelled diagram, explain the working of a simple microscope. State uses of a simple microscope.
(OR)
What does a simple microscope consist of? What is the order of magnification obtained by a simple microscope? What is a simple microscope used for?

Which is the energy currency of the cell? Explain.