AQA GCSE Separate Science Biology – Paper 2 Higher Tier Predicted Paper 2023 with marking schemes

AQA GCSE Separate Science Biology – Paper 2 Higher Tier Predicted Paper 2023 with marking schemes Name …………………………………………………………………… Date ………………… 1 hour 45 minutes allowed. You may use a calculator. Grade boundaries These are VERY rough guesses! Getting a 7 on this paper does not guarantee you the same mark in the exam. • 9 70% • 8 60% • 7 50% • 6 45% • 5 35% • 4 30% • 3 25% 01 a) The image shows three dogs. They are all members of the same species. What is the definition of a species? [2 marks] b) The image shows different breeds of dogs that look very different. What term is used to define physical differences between the dogs? [1 mark] c) The table below shows the classification for dogs. Complete the table. [2 marks] Animalia Phylum Chordata Class Mammalia Carnivora Family Canidae Genus Canis familiaris d) Give the binomial name for dogs. Use the table above. [1 mark] e) Give one reason why binomial names, instead of conventional names, are used by scientists. [1 mark] f) When the new ‘three-domain system’ was introduced, dogs were classified into the Eukaryota. Explain how the ‘three-domain system’ was developed. [3 marks] g) Dogs are closely related to wolves. Give two pieces of evidence that scientists can use to show that dogs are closely related to wolves. [2 marks] 02 The image shows a cranberry plant. The cranberry plants grow in bogs which are often flooded. a) Cranberries have some specific adaptations. For each of the following – explain how this helps the plant to survive and reproduce: [3 marks] i. Bright red fruit. ii. Can live for up to 6 months without oxygen to their roots. iii. One stem of a cranberry plant can produce a new plant. Features of plants have been changed over many years as farmers have bred them for specific characteristics. An example is broccoli which is the result of hundreds of years of breeding wild cabbage plants. The parts of broccoli that we eat are large flower buds with thick stems. Original wild cabbage plants had small flower buds, thin stems and large leaves. b) Describe the process of selective breeding that farmers would have used to produce modern broccoli plants from the original wild cabbage plants. [4 marks] c) Name two other desired characteristics in plants that they have been selectively bred for. [2 marks] d) Some major crop plants which have been highly selected for are at risk of being lost to diseases. Explain why. [2 marks] e) Some plants, such as strawberry plants can reproduce both sexually and asexually. Give advantages and disadvantages for these two methods of reproduction. [6 marks] f) Golden rice is an example of a plant that has been genetically engineered to produce vitamin A. It has helped to prevent vitamin A deficiencies in children where their diet consists mainly of rice as it is hard to grow other crops. i. Describe how scientists transferred the gene that produces vitamin A from tomatoes into rice. [3 marks] ii. Give two reasons why some people might be against genetically modified crop plants. [2 marks] 03 Around the world, millions of hectares of forest is being lost every year. The graph below shows the breakdown of the causes of deforestation in tropical (South America, South East Asia and Africa) and temperate (North America, Europe, Russia, China and Oceania) regions. a) Calculate the percentage increase of trees lost to agriculture in tropical regions compared to temperate ones. [3 marks] b) Explain why more deforestation for agriculture and fuel is occurring in tropical regions than temperate regions. [2 marks] c) In the last 20 years, the annual area of trees lost to wildfires has increased from 2.52 million to 9.26 million hectares. Suggest reasons for this. [2 marks] d) Deforestation reduces biodiversity and causes some species to become extinct. i. What is meant by the term biodiversity? [1 mark] ii. Give one reason why it is important to maintain biodiversity to prevent species from extinction? [1 mark] a) Forests are an example of an ecosystem which can contain many interconnected food chains. Here is an example of a food chain from an oak forest: Oak tree  Moth caterpillar  Blue-tit Draw and label a pyramid of biomass for this food chain. [2 marks] b) The oak tree leaves contain about 1620kJ of energy. Only 10% of energy is transferred to the next trophic level. Calculate how much energy from the oak leaves can be used by the blue-tits for growth. Show your working. [2 marks] c) Energy is lost at each trophic level of this food chain. Explain why. [2 marks] d) Both forests and fisheries can be managed in a sustainable way. Explain what makes a fishery sustainable. [3 marks] a) The drawing shows part of a DNA molecule. i. Name the structures labelled A-C. A [3 marks] B C ii. Using the diagram explain why DNA is a polymer. [2 marks] b) Streptococcus bacteria are among the family of bacteria which causes illnesses such as a sore throat. Streptococcus bacteria and other very simple organisms reproduce asexually. Name the process by which bacteria replicate. [1 mark] c) Streptococcus bacteria are very small at 1.2μm in diameter. Use the following equation to determine the volume of a single cell. Give your answer to two significant figures. Volume = 4