14. T and B lymphocytes __ 1. are polymorphonuclear 2. are involved with specific immune function 3. proliferate excessively in leukopenia 4. are most active against parasitic worms

## Step 1<br />The problem is asking us to identify the correct statement about T and B lymphocytes. T and B lymphocytes are a type of white blood cell that plays a crucial role in the immune system.<br /><br />## Step 2<br />Let's analyze each statement:<br /><br />1. T and B lymphocytes are polymorphonuclear. This statement is incorrect. Polymorphonuclear refers to a type of white blood cell that has a multi-lobed nucleus, such as neutrophils, eosinophils, and basophils. T and B lymphocytes, on the other hand, have a single, round nucleus.<br /><br />2. T and B lymphocytes are involved with specific immune function. This statement is correct. T and B lymphocytes are indeed involved in the specific immune function. They are responsible for recognizing specific antigens and mounting an immune response against them.<br /><br />3. T and B lymphocytes proliferate excessively in leukopenia. This statement is incorrect. Leukopenia is a condition characterized by a decrease in the number of white blood cells, including T and B lymphocytes. Therefore, it is not accurate to say that T and B lymphocytes proliferate excessively in leukopenia.<br /><br />4. T and B lymphocytes are most active against parasitic worms. This statement is incorrect. While T and B lymphocytes do play a role in the immune response against parasitic worms, they are not the most active against them. Other types of white blood cells, such as eosinophils, are more active against parasitic worms.