Multimedia in a Presentation
SL.5.5
Read the text, then answer the questions.
What Sleep Is For
Sleep is not switching off. Parts of the brain are busier asleep than awake. Two claims are well supported. The first is that sleep consolidates memory: during deep sleep, the day's experiences are replayed and moved from short-term storage into long-term. Interrupt deep sleep and recall of the previous day drops measurably. The second is that sleep clears waste. The spaces between brain cells widen during sleep, and fluid washes through, removing proteins that build up while awake. A third claim — that a particular number of hours suits everybody — is not supported. Need varies with age and between individuals, and self-reported sleep is unreliable. Teenagers are a special case. Their body clocks genuinely shift later at puberty, which is a biological fact rather than a preference, and school start times mostly ignore it.
- 1. What would a diagram for this text need to show?
- 2. Determine two main ideas of this text and explain how details support each.
How a Vaccine Teaches the Body
Your immune system learns. Meet a disease once and, if you survive it, you are usually protected afterwards. A vaccine gives the lesson without the disease. The method is old. In eighteenth-century Britain, milkmaids were known not to catch smallpox. Edward Jenner reasoned that the cowpox they caught from cattle was protecting them, and in 1796 he tested it on a boy — a procedure no ethics committee would permit now. A modern vaccine shows the immune system a harmless piece of a pathogen: a killed virus, a weakened one, or a single protein from its surface. The body makes antibodies against that piece, and keeps the recipe. Because the recipe is kept, the real pathogen is met by a defence already in place. There is a second effect. If enough people are immune, the pathogen cannot find a chain of hosts, so those who cannot be vaccinated are protected too. That effect fails below a threshold, which is why coverage rather than availability is what matters.
- 1. What would a diagram of vaccination need to show?
- 2. Determine two main ideas of this text and explain how details support each.
LessonPrint · SL.5.5 · Set 22 · free to copy for classroom use