<h3><u>Answer;</u></h3>
A. Gas exchanges takes place by diffusion.
B. It is an open system.
<h3><u>Explanation</u>;</h3>
- Most molluscs and arthropods have an open type of circulatory system.
- Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.
- Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
Answer:
The correct answer option is C. They are target specific.
Explanation:
We are to determine whether which of the given statements is true about antibody.
Antibodies are a type of proteins which are present in the body to defend the foreign attacks that are in the form of antigens.
These proteins have a basic structure which consists of two pairs of polypeptide chains that are linked covalently via disulfide bonds.
Each antibody recognises one specific antigen and this feature is called as antibody specificity.
Answer:
recombinat DNA , epidemiology,
