When confronted by an invader, an is produced to protect the body from future invasions?

an Antibody!

Hope this helped!

~Just a girl in love with Shawn Mendes

Antibody

Explanation:

The pathogen or an invader when enters the body it gets encountered by the immune cells in the body. The lymphocytes when interacts with the antigen/pathogen or invader, it produces a immune response.

The immune response results in production of memory cells and antibody producing cells. The antibody producing cells forms antibody which kills the invader and the memory cells generates memory to prevent the body when second time encounter occurs with the same invader.

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.