OCR 2023 GCSE Combined Science B Twenty First Century Science J260/01: Biology (Foundation Tier) Question Paper & Mark Scheme (Merged)

2 © OCR 2023 Chemical Bacteria in the gut compete against pathogens Microbial Skin stops pathogens entering the body Physical Stomach acid destroys pathogens 1 Some bacteria are pathogens that cause diseases. (a) Our blood contains white blood cells. They help protect us against pathogens. (i) Write down the name of the organ that pumps the blood around our body. ...................................................................................................................................... [1] (ii) Which system are white blood cells a part of? Tick () one box. Gas exchange system Immune system Nervous system [1] (b) The human body has different types of defences against pathogens. Draw lines to connect each type of defence with the correct example. Type of defence Example [2] 3 © OCR 2023 Turn over (c) Beth has a cut on her finger. Platelets in Beth’s blood help to seal the cut so bacteria can’t get into it. Which two statements explain how her platelets do this? Tick () two boxes. They carry oxygen. They make antibodies. They make her blood clo