Solution
Cut open an onion.
Use forceps to peel a thin layer of epidermis from the inside.
Lay the layer of epidermis on a microscope slide.
Add a drop of iodine solution to the layer.
Carefully place a coverslip over the layer.
Observe it under a microscope to see onion cells.
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>
Answer:
1 living organisms are composed of one or more cells.
2 The cell is the basic unit of structure and organization in organisms.
3 Cells arise from pre-existing cells.
Elephants, who are important grazers, are instrumental in transforming woodlands into grasslands. This has a tremendous impact on other species that depend on the grass for their survival. The significance of the elephant in this example is B. keystone species.