Through parents having intercourse, so the genes are passed on to generation to generation,
<span>a. the effect of oil spills on marine animals</span>
Cells require a structure that regulates the transfer of material in and out of the cell. This structure is the –
Cell membrane.
Macrophages
Using the receptors on their surface and through the facilitation by immunoglobulins that attach to the foreign matter, macrophages 'hold' the foreign bodies in the body and 'ingest' them through phagocytosis. Lysozymes in the cells then in 'digest' the foreign matter.