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(a) State three features, visible in Fig. 1.1, that show that the chorus cicada is an insect.
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(b) Insects are classified in the same group as crustaceans, arachnids and myriapods.
Name the group that contains all these animals.
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Evolutionary relationships between different species are investigated by examining DNA.
(c) State precisely where DNA is found in a cell.
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Small sections of DNA in 14 species of cicada found in Australia, New Caledonia and New Zealand (1 to 14) were examined for similarities and differences.
The results of the DNA examination of these species were used to make a diagram showing how these cicada species may have evolved. Species that are closely related are grouped together on the right of Fig. 1.2.
The brackets show that the cicada species in New Zealand are in two separate groups.
(d) It is suggested that the eight cicada species in New Zealand originated from two migrations, A and B, from Australia as shown in Fig. 1.3.
Explain how the results in Fig. 1.2 support the idea that the eight cicada species in New Zealand originated from two migrations of cicadas as shown in Fig. 1.3.
You can use the numbers from Fig. 1.2 in your answer.
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Islands in the Pacific have been colonised by populations of animals that have migrated from Australia, mainland Asia and the Americas. Over many generations these populations have changed. Now they are unable to breed with animals of the original populations in Australia, mainland Asia and the Americas.
(e) Explain how natural selection has resulted in changes in the populations of animals on islands in the Pacific.
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(a) Define the term excretion.
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Fig. 2.1 shows a kidney tubule and the blood vessels associated with it.
(b) Table 2.1 shows some processes that occur in a kidney.
In Table 2.1, write the letter of the part shown in Fig. 2.1 where each process occurs.
You must put one letter in each box. You may use the same letter more than once.
[Table_1]
| process | letter |
| ------------------------------------------------------ | ------ |
| filtration of blood | |
| reabsorption of most of the solutes from the filtrate | |
| water is absorbed by osmosis to determine the concentration of urine | |
| unfiltered blood returns to the renal vein | | [4]
(c) Table 2.2 lists the components of blood, filtrate and urine.
[Table_2]
| component | blood | filtrate | urine |
| ---------------- | ----- | -------- | ----- |
| red blood cells | ✓ | ✗ | ✗ |
| white blood cells| ✓ | | |
| plasma proteins | ✓ | | |
| glucose | ✓ | | |
| urea | ✓ | | |
| salts | ✓ | | |
| water | ✓ | | |
Complete the table by using ticks (✓) and crosses (✗) to show whether or not each component is present in filtrate and in urine of a healthy person. The first component has been done for you. [2]
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Fig. 3.1 shows the process of producing mycoprotein, a form of single cell protein, by growing the fungus, Fusarium venenatum, in a fermenter. The fungus produces large quantities of hyphae which are extracted and processed as shown.
(a) (i) Name an enzyme used to digest the corn starch.
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(ii) Explain why it is necessary to digest the corn starch.
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(b) Explain why sterile conditions are necessary in the fermenter.
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(c) In 2008, there were riots in some parts of the world in protest against shortages of staple foods, such as rice.
Explain why it is better ecologically for people to eat foods made from plants rather than from animal products, such as meat.
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(d) Describe three possible advantages of using foods prepared from mycoprotein as substitutes for animal products, such as meat.
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(e) Discuss whether production of foods made from mycoprotein might \text{not} reduce food shortages in the future.
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Niusila Opeleoge from Samoa holds a Commonwealth Games record for weightlifting. He can lift 338 kg. Weightlifting is an example of an anaerobic sport as muscles act over a short period of time.
(a) Write a balanced chemical equation for anaerobic respiration in muscle.
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Weightlifting involves contraction of the muscles of the arms.
Fig. 4.1 shows the muscles that move the forearm.
(b) Describe how the muscles identified in Fig. 4.1 work to move the forearm up.
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Exercise that occurs over a longer period of time than weightlifting often involves aerobic respiration as well as anaerobic respiration.
Fig. 4.2 shows the oxygen consumed by an athlete during and after a 5000 metre race.
(c) Describe the athlete's oxygen consumption during and after the race as shown in Fig. 4.2.
You will gain credit for using the figures in the graph to support your answer.
during .......................................................................................................................................................... after ....................................................................................................................................................... [4]
(d) Explain why the oxygen consumption does not return immediately to the resting level after the exercise is finished.
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(a) Fig. 5.1 shows the global use of nitrogen fertilisers between 1960 and 2003.
(i) Calculate the percentage increase in the global use of nitrogen fertilisers between 1970 and 1987. Show your working.
Answer ..........................................% [2]
(ii) Explain why the use of nitrogen fertilisers has increased.
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(b) Some farmers increase the fertility of their soils by adding organic fertilisers, such as manure, and by using legume crops in a crop rotation. Manure contains protein, urea and ammonia in the waste from farm animals.
(i) Explain how nitrogen, in the form of nitrate ions, becomes available in a soil after the addition of manure.
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(ii) Explain why legume crops, such as peas, beans, alfalfa and clover are used in crop rotations.
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(c) The overuse of fertilisers can lead to environmental problems. Soils, rivers, lakes, the sea and the atmosphere have all been affected by this pollution.
Outline the undesirable effects of the overuse of fertilisers.
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Haemoglobin is a protein that is made inside developing red blood cells in the bone marrow.
(a) (i) State the function of haemoglobin.
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(ii) Name the small molecules that are combined to make haemoglobin.
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(iii) Name the mineral ion provided in the diet that is needed to make haemoglobin.
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There are many different varieties of haemoglobin. The gene for haemoglobin exists as two alleles, $Hb^A$ and $Hb^S$.
People with the genotype $Hb^SHb^S$ have a condition called sickle cell anaemia.
(b) Describe the features of sickle cell anaemia.
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(c) The allele for $Hb^S$ is rare in many parts of the world, but it is more common in parts of tropical Africa.
Explain why $Hb^S$ is more common in parts of tropical Africa.
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(d) The parents of people with sickle cell anaemia rarely have this condition.
Explain, using a genetic diagram, how two parents who do not have sickle cell anaemia may have a child with the condition.
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parental genotypes ............... × ...............
gametes ............... ............... + ............... ...............
genotype of child with ...............
sickle cell anaemia ...............
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(e) Sickle cell anaemia is an example of variation in humans. There are many causes of variation, including nuclear fall-out.
Suggest how nuclear fall-out could cause variation in humans.
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