In the following passage, each numbered space can be filled with a biological term.

Each type of cell has specific molecules on its (1) that identify it. An antibody is a (2) with two (3) binding sites. Antibodies are made and released by (4) cells.

Vaccines can provide protection for individuals and populations against disease. The response to a vaccine is an example of (5) immunity.

(6) immunity occurs when a large proportion of a population becomes immune to a disease.

Write the correct biological term beside each number below that matches the space in the passage.

1

2

3

4

5

6

There is currently no effective vaccine available for HIV.

Suggest one reason why.

Table 1 shows the action of two antibiotics.

Using the information in Table 1, explain why each antibiotic is not effective against HIV.

Ciprofloxacin

Penicillin