Question

D. Lab Activity Ill: Beriberi In 1887 a strange nerve disease known as beriberi attacked the people in the Dutch East Indies. Symptoms of the disease included weakness and loss of appetite, with victims often dying of heart failure. Scientists thought the disease might be caused by bacteria so they injected chickens with bacteria from the blood of patients with berberi. Chickens injected with infected blood became sick but so did a group of chickens that were not injected with the infected blood One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole grain rice, but during the experiment the chickens were fed polished rice. Dr. Eijkman researched this interesting case further and found that polished rice lacked thiamine, a vitamin necessary for good health What was the question being asked by these scientists? What was the hypothesis? How was the hypothesis tested? What were the independent and dependent variables? What was the control group?

Answer 1

1. They wanted to find the causative agent of the disease. the question is, what is the reason behind the death of these people?

2. The hypothesized that the bacteria might be the causative agent.

3. The hypothesis is tested by injecting the blood sample from patients to chickens

4. A dependent variable is the one which is under test. death is dependent variable. An independent variable is one which changes. so life is the independent variable.

5. Control group is the chickens that are not injected with the infected blood.

6. the scientist did not actually included the and infected chickens in their experiment. But this infected chickens also show the expected result that is death. Only if we have a control group we can be sure that our experiment is kept under our control.

7. Based on the experiment it is clear that Bacteria is not a causative agent hence the hypothesis must be rejected

8. The new hypothesis must revolve around the vitamin deficiency. It can be tested by having a group fed with the vitamin and having another group deficient of vitamin and tested for similar symptoms related to disease.