Answer:
THEY ALL INVOLVE FIGHTING PATHOGENS
Explanation:
The immune system which is involved in defending the body against infections are diseases involves three lines of defense which are all involved in fighting against pathogens. Pathogens are invaders which when introduced into the body causes harm and therefore makes us sick. The body's first line of defense includes the physical barriers such as the skin, mucous membrane; chemical barriers such as tears, saliva, gastric acid in the stomach. These helps to keep the pathogens from entering the delicate parts of the body and once the pathogens find their way out of the reach of the first line of defense, the second line of defense is initiated. This includes inflammatory effects, swelling, redness, phagocytosis by neutrophils and macrophages. The third line of defense is the actions of lymphocytes which acts on invading microbes. The lymphocytes are of two types; the B and T cells. B cells produces antibodies which fight the antigens and T cells attack the infected cells of the body. There is also the memory cells which keeps information about the invading microbes for future attacks. This enables the body to respond swiftly when next the same type of pathogens attack.
The answer is: a relatively large electron cloud.
Atom is composed of the nucleus and the electron cloud.
Protons (positive particles) and neutrons (neutral particles) are in the nucleus of an atom and electrons (negative particles) are in the electron cloud.
Nucleus is in the centar of the atom atom and electron cloud is surrounding it.
Atoms have their mass concentrated in a very small nucleus.
1) 100s of millions of years ago Trees and plants fall into swamps
2) Layers of rotting plant matter builds up underwater
3) Over millions of years the weight of layers heat the plant matter and turn into Peat
4) Over millions of years more pressure and heat turns Peat into coal
Answer:
4
Explanation:
The zeros before a non zero digit do not count as significant figures so there are 4 sig figs in the number
Compounds are elements and its a pure substance with a gised composition.
Mixtures two or more subtances mixed to together.There are 2 type of mixtures.
Homegenous Mixtures (Solutions)-Two or more substances mixed but is uniform, you cant see the different mixtures.
Ex:Sugar mixed with water.The sugar dissolves and becomes one with the water.
Heterogeneous Mixtures-Two or more substances mixed but is not uniformed.You can see all the substances put into the mixture.
Ex:A salad, you can see whats all mixed in the sald and can pick it apart.
