Question

Write short notes on any two of the following.
i. Disease caused by Bacteria and cure
ii. Plasmids
iii. Dengue fever.

Answer 1

i. Many human infections are caused by either bacteria or viruses. Disease caused by bacteria are called as bacterial infections. Pathogenic bacteria get access into the body by various ways like through cuts, contaminated food or water, faeces, inhaltion of droplets, etc. Antibodies produced by the immune system help in their destruction. The bacterial disease can be cured with antibiotics that disrupts the bacterium’s metabolic processes. Immunization can also be carried out in order to prevent many important bacterial diseases such as Hemophilus influenza Type b (Hib), tetanus and whooping cough.

ii. Plasmids are small, circular, double-stranded DNA molecules. They are extrachromosomal material. They are self replicating in nature. They exist in bacterial cells and in some archea and eukaryotes. The genes carried by plasmids provide bacteria certain genetic advantages, such as antibiotic resistance.

iii. Dengue fever is a mosquito-borne disease caused by the dengue virus. It is transmitted by mosquito bite. Symptoms include high fever, headache, vomiting, muscle and joint pains and skin rash. Treatment is only symptomatic. Rest and fluid intake for adequate hydration is advised in dengue fever.