The brain is incorrect. Its the nucleus (the brain is an organ not a organelle)
hope that helps :)
Answer:
Life is based on carbon; organic chemistry studies compounds in which carbon is a central element. The properties of carbon make it the backbone of the organic molecules which form living matter. Carbon is a such a versatile element because it can form four covalent bonds.
Explanation:
<span>Antibodies. A. k.a. immunoglobulins. They are produced by a group of white blood cells called B lymphocytes (or B cells). There are 5 classes of immunoglobulins; IgM,IgA,IgE,IgG and IgD.The classes of antibody diifferent both in their constant region and in their activity.IgG, the most common antibody, and is found mostly in the blood and tissue fluids, and IgA is localized in the mucous membranes which line the respiratory and gastrointestinal tracts.</span>
D because having a sonogram is irrelevant when you are about to deliver the baby
