problems and solutions to a changing environment

Question 1

what is a drug?

Answer 1

a drug is chemical substance that changes the way in which the body works

Question 2

what are stimulants?

Answer 2

e.g. caffeine and they increase the speed of neurotransmission across synapses, they make us feel energetic and awake

Question 3

what are the damages caused by smoking?

Answer 3

/ the sticky tar in cigarette smoke contains chemical substances called carcinogens, these can cause lung or mouth cancer
/ nicotine makes it addictive
/ oxygen binds the haemoglobin inside red blood cells, and is then transported round the body. Carbon Monoxide combines with haemoglobin, reducing the amount of oxygen red blood cells can carry - body cells receive less oxygen

Question 4

780 - 90 = 690 = 690/780 x 100 - 88.4 - 100

Answer 4

=12.4

Question 5

what is a mutualistic relationship?

Answer 5

for example: nitrogen fixing bacteria live inside legumes:
/ the bacteria are protected from the environment and obtain chemical substances from the plant that they use as food
/ the plant gets nitrogen compounds (nitrates) from the bacteria, which it uses for growth
/ both the bacteria and the plant benefit from the relationship