Edxcel alevel biology past papers: some of the blood plasma of individuals who have survived infection wtih Ebola can be collected. This can be used in the treatment of individuals currentlty infected with Ebola. Explain why the blood plasma from survivors can be used to treat new cases of Ebola infection.

This was the only treatment options adopted for the Ebola in  1995 in the Democratic Republic of Congo. The assumption was that immune response is generated by the virus in the WBC of the infected individuals. These response produce antibodies.

A total if 8 patients were transfused with these blood contained antibodies, but one of these died, the remaining 7 patients survived.

The antibodies were believed to  have  multiplied(produced b-cells) to neutralize the Ebola virus(antigens)  and to ensure the survival of the patients

Explanation:

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.

1. dermis

2. chemical

3. urine

4. viruses

5. antibodies