Tears and mucous membrane are part of the General defense
system. The General defense system of the body consists of the skin, clotting,
sweat glands, lysozyme, mucous membranes, nasal hairs, cilia, hydrolic acids,
and the vagina. General defense systems have a vital role in giving barriers to
stop bacteria in entering our body which will make us sick.
True - The weight of an object is equal to the force of gravity acting upon the object. .... A contact force results from the physical contact between two objects.
1) they have similar chemical properties.
for example fluorine from the 17th column is a non metal so does all the elements of that group.
2)they have same valence electrons in their outermost shell
example
electronic configuration of
hydrogen 1, lithium 2,1, sodium 2,8,1 and so on.
3) have same valency.
The endosymbiosis explains how eukaryotic cells may have evolved from prokaryotic cells.
