The process of converting food to energy on a cellular levelis called metabolism. Microorganisms responsible for spreading of diseases are called pathogens. They are various microorganisms which transfer easily from animals to humans through air, water, contact .The five major types which are responsible for spreading of the diseases are bacteria, viruses, fungi, protozoa, and helminths. Direct contact occurs when an individual is infected by contact with the reservoir, for example, ingesting infected meat. Indirect contact occurs when a pathogen can withstand the environment outside its host for a long period of time before infecting another individual. The fecal-oral route of transmission, in which sewage-contaminated water is used for drinking, washing, or preparing foods, is a significant form of indirect transmission, especially for gastrointestinal diseases such as cholera, rotavirus infection, cryptosporidiosis, and giardiasis.These modes of transmission are all examples of horizontal transmission because the infectious agent is passed from person to person in a group. Some diseases also are transmitted vertically; that is, they are transmitted from parent to child during the processes of reproduction (through sperm or egg cells), fetal development, or birth. Diseases in which vertical transmission occurs include AIDS and herpes encephalitis (which occurs when an infant contracts the herpes simplex type II virus during vaginal birth).Sewage includes wash water, water from toilets, and storm run-off. These fluids may carry the pathogens for many waterborne diseases, including giardiasis and hepatitis.
The tiny portion of unshared DNA makes a world of difference: it gives us, for instance, our bipedal stance and the ability to plan missions to Mars. Scientists do not yet know how most of the DNA that is uniquely ours affects gene function. But they can conduct whole-genome analyses—with intriguing results. For example, comparing the 33 percent of our genome that codes for proteins with our relatives’ genomes reveal that although the sum total of our genetic differences is small, the individual differences pervade the genome, affecting each of our chromosomes in numerous ways. We as a human actually only invented very little thing genetically. We mostly re-use the parts from our common ancestor with Chimpanzee. However, we have duplicated many genes in the genome; as a result, a new function can arise from the quantity and location of the expression of pre-existing genes.
– PADMA PRIYA, I-YEAR, PGDM