22:39 a Tido & Nido 45 minutes ago 4 42% 2 S yable for another person, e.g. being driven in a very fast car. wing questions with your class. why is the short-term secretion of adrenaline important for athletes running in a one hundred-metre race? what ifestyles do you think are associated with stress? (What types of occupations or jobs are stressful?) why is the long-term secretion of adrenaline harmful to the body?) & why do you think stress-related illnesses, such as heart disease and strokes, are increasing in today's society What can people do to reduce stress in their lives? Surf the Internet to find out more. b) Exercise REFE 1. Insect larvae, such as caterpillars or maggots, grow by shedding their skin in a process called moulting. When an insect larva moults, it can either become a larger, new larva or it can turn into a pupa. This process is controlled by hormones, one of which is called juvenile hormone or JH. High levels of JH cause the larva to become an even bigger larva wher moults. When the amount of JH falls below a certain level, the larva turns Into a pupa. (a) What would happen to the larva shown in the picture if the level of JH always stays high? (b) What effect would this have on the number of this species of insect in a particular area? A particularly annoying group of insects feeds on stored grain such as rice. The adults lay their eggs on the rice grains and the larvae eat the rice. Unfortunately, these insects are becoming increasingly resistant to insecticides. Research scientists are now beginning to look at a group of chemicals which resemble JH as a means of controlling these insects. (c) What effect would the administration of the artificial JH have on an insect? (d) These artificial JH molecules have proved to be very successful in A larva controlling cat fleas and cockroaches. However, they have not been S successful in reducing the damage caused by insects whose larvae eat stored food. Su You may need to do some research on the life cycles of fleas and cockroaches. 2. The diagram on the right is a graph which shows how the concentration of blood sugar and the concentration of a certain hormone in a person's blood changed over a period of five hours. (a) From the graph, what can you infer about the change in blood glucose concentration over five hours? (b) What can you deduce about hormone A? (c) Children suffering from a lack of hormone A 2 in the blood Period Period Period 3 1 may be taught to inject the hormone into their veins. Why is this dangerous? Time/h ||| = О く Reply