Draw Inferences
RI.4.1
Read the text, then answer the questions.
How Penicillin Was Found
In 1928 Alexander Fleming went on holiday and left a stack of dishes on a bench. Each held a colony of bacteria. When he came back, one dish had a spot of mould on it. Around the mould was a clear ring where the bacteria had died. Fleming realised the mould was producing something that killed bacteria. He named it penicillin and published a paper. Almost nobody noticed. Ten years later, Howard Florey and Ernst Chain read that paper and tried to make penicillin in quantity. That turned out to be the hard part: it took two thousand litres of mould fluid to treat one patient. By 1944 the problem had been solved and penicillin was reaching soldiers in the field.
- 1. Why does the text mention that Fleming went on holiday?
The Accidental Photograph
In 1895 Wilhelm Röntgen was working with a covered tube in a darkened room when he noticed a screen across the laboratory glowing. Something was passing through the cover and crossing the room. He did not know what it was, so he called it X — the unknown. He spent seven weeks alone in the laboratory testing it. He put wood, rubber and metal in the way. Metal stopped it; the rest did not. Then he asked his wife to put her hand between the tube and a photographic plate. The picture showed the bones of her hand and her wedding ring. Within a year, X-rays were being used in hospitals. Röntgen refused to patent them.
- 1. Why did Röntgen work alone for seven weeks?
LessonPrint · RI.4.1 · Set 3 · free to copy for classroom use