What is an antibodies , please don't use internet

Explanation:

Antibody

Drug class

Description

An antibody, also known as an immunoglobulin, is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. 

Explanation:

An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens.

it has one origin of replication, but it proceeds in two directions - d)

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.