A wide range of organisms belonging to bacteria, viruses ,fungi ,protozoans ,helminthes etc. Could cause diseases in man Such pathogens can enter our body by various means multiply and interfere with normal activities resulting in morphological and functional damage 1.Typhoid Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings.These pathogens generally enter in the small intestine through food and water contaminated with them migrate to other organs through blood Sustained high fever (39-40 c) , weakness, stomach pain , constipation , headache , and loss of appetite are some of the common symptoms of this disease. Complications:- Intestinal perforation and death may occur in severe cases 2.Common cold Rhino viruses represent one such group of viruses which cause one of the most infectious human ailments the common cold. They infect the nose respiratory passage but not the lungs .The common cold is characterised by nasal con
Phylum porifera It is the first phylum of kingdom Animalia.Members of this phylum are commonly known as sponges Examples of porifera are as follows 1. Sycon (sypha) 2.spongilla(freshwater sponge) 3.Euspongia(Bath sponge) Features of phylum porifera are given below 1.They are generally marine 2.Mostly asymmetrical animals 3.They have a cellular level of organisation 4.Sponges have a water transport or canal system 5. Digestion is intracellular 6.The body is supported by Skeleton made up of spicules or spongin fibres 7.Sexes are not separate (Hermaphrodite) i.e eggs and sperms are produced by the same individual 8.Fertilisation is internal and development is indirect having a larval stage