biology for grade 7

The blood is a fluid connective tissue. It is opaque and somewhat sticky. It is more viscous than distilled water with a viscosity of 4.7 and slightly alkaline in nature, Oxygenated blood is bright red while the deoxygenated blood is purple coloured. Blood flows in the blood vessels due t..

India is a tropical and subtropical country with a latitudinal position between 8 o M to 32 o M. As compared to Western countries, we are bestowed with fairly good sunlight almost during the entire year. Average sunshine hours available in different parts of our country varies from 8 hours to 13..

Balanced Diet - Diet is the food on which an individual lives. A balanced diet may be defined as the one which contains all the essential nutrients like carbohydrates, fats, proteins, minerals and vitamins in the correct proportion for the normal growth and development of the body. A balanced diet ..

Functions of Circulatory System - The functions performed by the circulatory system in all animals are 1) Transport of nutrients like glucose, amino acids, vitamins, minerals 2) Transport of oxygen from the organs of respiration to the body cells. 3) Transport of carbon dioxide from the body cells ..

The electrons lost by P 6 8 0 (PS-II) are taken up by P 7 0 0 (PS-I) and do not get back to P 6 8 0 i.e., unidirectional and hence it is called non- cyclic phosphorylation. The electrons pass through the primary acceptor, plastoquinone (PQ), cytochrome complex, plastocyanin (PC) and final..

1) Destruction of wild life leads to loss of valuable materials. 2) Disappearance of any link in a food chain upsets nature's balance and creates problems. 3) New improved varieties of crops and other useful animals are derived from their wild relatives by genetic modification. This indicates the ..

. The electrons of plastocyanin are picked by PS-I. Simultaneously, the pigment molecules of PS-I complex absorb solar radiation and transfer their absorbed electronic excitation (energy) to PS-I reaction centre - P 7 0 0 . P 7 0 0 gets excited and exudes an electron, which goes..

Cranial nerves are those that connect the different parts of the body to the brain. There are 12 pairs of cranial nerves. Cranial nerves may be sensory, motor or mixed. For example: 1 s t and 2 n d pairs of cranial nerves are Olfactory (pertaining to smell) and Optic (pertaining to sight..

They are also called leucocytes. They lack haemoglobin and are therefore colourless. They are nucleated and amoeboid.The amoeboid nature of the leucocytes helps them to squeeze through the walls of the blood vessels in order to engulf bacteria. They do not contain haemoglobin. They number 6000 to 8..

The following is a list of the approximate number of species known in the animal groups regarded as major phyla. Protozoa 35,000 Porifera 9,000 Coelenterates 9,000 Platyhelminthes 20,000 Aschelminthes 12,000 Annelids 15,000 Arthropods 9,60,000 Molluscs 50,000 Echinodermata 7,000 Chordates..