iii Neurones carry information in the form of electrical impulses. Sensory neurones carry impulses from receptors to the central nervous system.

Transcription

1 Page 4 Coordination 1 a Brain (1); spinal ord (1) i Motor (1) i Neurones arry information in the form of eletrial impulses. Sensory neurones arry impulses from reeptors to the entral nervous system. (3) Page 4 Reeptors 2 D B A C Rememer: Chek whih grade you are working at. (2) 3 a D C A B i The heart (1) Adrenaline provides more oxygen to musles (so you an run faster) (1) Page 5 Reflex ations 1 a C (1) i Transmitter sustane / Aetylholine (1) Transmitter sustane (ontents of X) is released into the left and diffuses aross the left and sets up impulse in the next neurone (2) Page 5 In ontrol 2 a A (1) 1 from the skin in sweat (1); 2 in urine (1); 3 from the lungs in reath (1) To replae (sodium and hloride ions) lost in sweat (1); to maintain their onentration in the lood/ so that ells an work effetively (1) d Makes the liver take gluose from the lood storing it as glyogen (2) 1

2 Page 6 Reprodutive hormones 1 a B (1) B (1) Page 6 Controlling fertility 2 a A (1) i The older the woman, the lower the suess rate (1) 3 a A (1) The suess rate is too low (1); uses up money etter spent on other health treatments (1); possile prolems for hildren of (very) elderly parents (1) (Any 2:) Could enourage people to have more sexual partners; ould enourage people to have sex more often; ould mean people stop using ondoms Page 7 Diet and energy 1 a We get our energy from the food that we eat, espeially fats, arohydrates and proteins. A alaned diet ontains the right amount of energy. People who eat a poor diet are said to e malnourished. (3) i The rate of hemial reations in ells / the ody (1) Katie s metaoli rate is faster (1); so she uses up energy faster (1) i Olivia ould do more exerise (1) Page 7 Oesity 2 a Frane (1) 28 % (1) In Russia, there are more oese women than oese men, in Canada, the perentages oese men and oese women are the same (1) d Oese people put more, stress / weight, on their joints (1); ause damage to the joint surfae / wear away artilage (1) 2

3 Page 8 Not enough food 1 a Lak of food redues resistane to (infetious) diseases i Energy taken in depends on the total amount eaten / what matters is the alane etween energy taken in and energy used / weight is lost only if energy taken in is less than energy used (Any 2:) They will not e ale to maintain this weight loss; weight will easily go ak on again they may feel ill; weak (after losing so muh weight so quikly) they may have lost a lot of water Page 8 Cholesterol and salt 2 a B (1) The lood arries holesterol in two forms, HDL and LDL. It is etter to have more HDL than LDL. Eating monounsaturated fats an help to redue lood holesterol. (3) (Any 3:) Plaques form; in walls of arteries; from holesterol; lots an form; heart musle does not get a good supply of lood; so does not reeive enough oxygen; musle an, stop working / die Page 9 Drugs 1 a A D C B You annot manage without it (1); if you stop taking the drug you experiene withdrawal symptoms (1) Page 9 Trialling drugs 2 a Tested on animals / human ells (in laoratory) (1) i A (mean age in years was the same) (1) B, C, D and E (1) i To ontrol a variale (1); every sujet took a pill (1); to provide a omparison point with those who took the drug (1) iv Ensures there is only one independent variale (1); removes posslity of oserver ias (1) 3

4 Page 10 Illegal drugs 1 a C (1) i Syringe may e ontaminated (1); with viruses (1) May eome addited (1); suffer withdrawal symptoms if they stop taking it (1) Page 10 Alohol 2 a Alohol (1) Alohol (1) d No, we only know how many were admitted to hospital (1); perhaps heroin is more likely to ause hospital admission than oaine (1) No, we only know how many were admitted to hospital (1); perhaps women take less of the drug than men / are less likely to e made ill y taking the drug (1) e Liver ells are damaged as they try to reak down alohol (1) Page 11 Toao 1 a D A B C i 1945 / 1946 (1) There is a time lag etween smoking and getting aner (1); early inrease in deaths from lung aner may not have een notied took a while for people to make a link etween the two (1) i Some other fator ould e ausing oth inreases Page 11 Pathogens 2 a A (1) (Any 2:) He realised that the ward with the most deaths was visited y dotors (1); he suggested they were passing disease-ausing sustanes etween patients (1); he asked dotors to wash their hands (efore and after touhing patients) (1) Page 12 Body defenes 1 a White lood ells help to defend us against pathogens. Some of them ingest ateria and viruses. Others produe hemials alled antiodies that destroy partiular ateria and viruses. i Phagoytosis (1) It is destroyed / killed (1); digested y enzymes (1) Page 12 Drugs against diseases 2 a Antotis kill (only) ateria (1); antotis do not kill viruses (1) C (1) 4

5 Page 13 Arms rae 1 Bateria an eome resistant to antotis y the proess of natural seletion. One example is MRSA. We an help to prevent this happening y using fewer antotis. 2 D (1) Page 13 Vaination 3 a A (1) 4 a 9000 (1) d No, eause we annot e sure the drop in ases was aused y the vaination (1) some other fator might have aused them to fall (1); ut there is a orrelation etween the use of the vaine and the fall in the numer of ases (1) Not everyone was vainated straight away (1); only year olds were vainated (1); as time went on a igger proportion of people had immunity (aept other well-argued suggestions) (1) (Any 4:) Referene to antigens; white lood ells respond; lymphoytes; serete antiodies; speifi to, antigen / TB / aterium; multiply; form memory ells; on next infetion ateria killed immediately 5

6 B1 B EVOLUTION AND ENVIRONMENT B1 answers Page 15 Hot and Cold 1 a 2 a 38 ºC (1) It loses heat to the old, air / ground (1) The old lood from the feet is warmed y the warm lood in the artery as it flows upwards (1) Page 15 Adapt or die 3 Plants and animals are adapted for survival in their haitat. Some plants have poisons in their leaves, whih harm insets that eat the leaves. Some plants have warning olours to deter predators. (3) 4 A (1) Page 16 Two ways to reprodue 1 a In asexual reprodution, the offspring are all genetially idential. They are lones. In sexual reprodution, the offspring get a mixture of genes from oth their parents. (3) Page 16 Genes and what they do 2 B (1) 3 a Nose shape and hair olour (1) B D A C D A C B Rememer: Chek whih grade you are working at. Kim ould e heavier eause she eats more or exerises less / Kim ould e etter at maths eause she works harder at it (1) They ould have inherited different (ominations of) genes from their parents (2) Page 17 Cuttings 1 D (1) 2 a (Any 2:) They might have different genes; they might e growing in different kinds of soil; one might have more water than the other; one might have more light than the other Aorns are produed y sexual reprodution, so they are genetially different (1); uttings only have genes from one parent, so they are genetially idential (1) Page 17 Clones 3 a Fertilisation happens when a sperm and an egg fuse together. They form a new ell alled a zygote. This divides to form a all of ells. The ells in the all an e split apart. Eah ell grows into an emryo, whih an e put into a different mother. (3) They are all formed from one zygote so they all have the same genes (1); they are genetially idential (1) 6

7 B1 B EVOLUTION AND ENVIRONMENT B1 answers Page 18 Geneti engineering 1 A (1) 2 The ateria ontain the human gene for making insulin (1); the gene arries the ode/instrutions for making human insulin (1) Page 18 Theories of evolution 3 a D (1) C (1) Only the ones with long neks reprodue (1); they pass on their genes to their offspring; all offspring ontain the genes for long neks (1) Page 19 Natural seletion 1 Organisms ompete for survival. Only the est adapted ones live long enough to reprodue. They pass on their genes to their offspring. Over many generations, most of the organisms will ontain these advantageous genes. (3) 2 a D (1) A (1) Page 19 Fossils and evolution 3 a D (1) 4 a From fossils (1) (Any 2:) Idea that they were adapted to their environment; more toes etter for running on wet ground; limate eame dryer; horses with fewer toes more likely to survive; and pass on their genes for fewer toes to their offspring; over time/many generations, all horses had only one toe Page 20 Extintion 1 B (1) 2 (Any 2:) Competition with the introdued rayfish / introdution of new ompetitor; ompete for limited resoures / not enough food for all; new disease may kill them; not enough new rayfish orn to replae the ones that die Page 20 More people, more prolems 3 As the human population inreases, we use more and more non-renewale fuels suh as oil. We also use more metals, whih we extrat from ores. We ause more pollution. 4 a The right hand part eyond the urrent year (1) Aout 2 illion (1) By aout three times (1) 7

8 B1 B EVOLUTION AND ENVIRONMENT B1 answers Page 21 Land use 1 Page 21 Pollution 2 Could ath diseases y taking in viruses / ateria / pathogens (1); examples holera, polio, gasroenteris, Weil s disease, allergi alveiolitis (1) 3 a (Any 2:) Extra nitrate made plants grow more; they shaded out plants eneath them; many plants died; ateria fed on them (so the aterial population inreased) The ateria respired (1); aeroially (1) 4 a Conentration of DDT inreases up the food hain (1); greatest onentration in the animals at the end of the hain (1) (Any 2:) DDT persists for a long time; in the environment / in the odies of animals; perhaps DDT is still eing used in other ountries Page 22 Air pollution 1 a B (1) Cause ronhitis / trigger asthma attaks (ut not atually ause asthma) (1) Page 22 What auses aid rain? 2 a Caron dioxide (1) It prevents the lood from arrying oxygen (1) They damage the lungs (1); ause reathing prolems / oughing / asthma attaks (1) d e D A C B The gases dissolve in water droplets reat to form aids (1); rain droplets ontaining aid fall to the ground when it rains (1) Kills trees y damaging their leaves / roots (1); washing away nutrients kills fish y making water aidi / toxi hemials washed in from soil (1) f The limestone neutralises the aid y reating with it (to form salts and water) (1); ph is raised (1) 8

9 B1 B EVOLUTION AND ENVIRONMENT B1 answers Page 23 Pollution indiators 1 a Chironomid larva (1) The ph is less than 5.4 / aout 5.1 (1) 2 a (Any 2:) Use the animals as indiators; different animals an live in different oxygen onentrations; find out whih animals are living in the water; math them to the oxygen onentration in whih they are known to live (Any 2:) Rat-tailed maggots; they an survive in the lowest oxygen onentration; raw sewage redues the oxygen onentration in the water. Page 23 Deforestation 3 C (1) 4 A (1) Page 24 The greenhouse effet good or ad? 1 A (1) 2 Caron dioxide traps energy that is radiated from the Earth. This stops the energy from esaping into spae. It keeps the Earth warmer than it would otherwise e. (3) 3 A (1) Page 24 Sustainaility the way forward? 4 a Less eletrty / less fuel needed to heat the house (1) i (Any 2:) Making sure we do not use resoures faster than they are eing replaed; using the environment in suh a way that we do not spoil it for the future; improving the quality of people s lives without damaging the hanes of our survival in the future (Any 2:) Less petrol used; so less oil needs to e taken from the ground; less aron dioxide released to the atmosphere (y the omustion of fuels); so less ontriution to gloal warming 9