Contemporary issue

This model set is based on old model. But it is very helpful for the students who appearing in see examination. Keep on practicing! Good luck! for the exam.

This question paper is based on old model but it is still useful for the st udents who are appearing in see exam.

The heart is a main pumping organ of our body. It helps to distribute the blood to all parts of the body. The heart is made up of special tissues known as cardiac muscles. It is able to pump the blood by rhythmic contraction and relaxation of its muscles. The blood circulation in a human body is double circulation. It involves the circulation of blood from heart to other parts fo the body except lungs and the circulation between heart and lungs. This means that the blood passes through the heart twice for each circulation of the body. Thus, there are two types of blood circulation in human body. (i) Systematic circulation      It is defined as the circulation of blood fom heart to all parts of the body except the lungs.  First, the pure blood is collected in the left auricle pushes the blood in the left ventricle. When the ventricle contracts, the pure blood is passed to the aorta thtough aortic valve. Then this pure blood is distributed by arteries and art...

Those animals which have no backbone or vertebral column are called invertebrates. They are classified into nine phyla. Characteristics of the animals of these phyla are given below: 1. Phylum: Protozoa i. They are unicellular organisms. ii. They are mostly found in water. iii. These animals have pseudopodia, flagella or cilia for locomotion. iv. They can be free living or parasitic. Some examples: amoeba,paramecium etc 2. Phylum: Porifera i. Porifera means pore bearer animals, commonly called sponges. ii. Most of them are marine organisms except spongilla. iii. They are diploblastic animals. iv. They respire through general body surface. V. They do not move from place to place, so they are called sessile. vi. The presence of calcium and silicon makes their body rigid and strong. vii. Sponges have two types of openings on their body surface i.e. ostia(mouthlets) and osculums(anus). Some examples: sycon, spongilla,euspongia etc. 3. Phylum: Coelenterata i. The body of ...