A portal of entry<span> is the site through which micro-organisms enter the susceptible host and cause disease/infection. Infectious agents enter the body through various </span>portals<span>, including the mucous membranes, the skin, the respiratory and the gastrointestinal tracts.</span>
Cells divide and reproduce in two ways, mitosis and meiosis. Mitosis results in two identical daughter cells, whereas meiosis results in four sex cells.
