1. 1
   A student is studying an onion bulb in a school laboratory. Using a hand lens, she observes that the outer skin of the bulb is made of a single layer of cells, all of a similar shape, all functioning together to form the protective outer skin of the bulb. Beneath this, several different types of cells are arranged together to form the fleshy storage layers of the bulb, which work together to allow the onion to store food and support the growth of a new plant.

   (a)

   Which term describes a group of cells with a similar structure that work together to perform a shared function, such as the single layer of cells forming the onion's outer skin?

   [1 mark]

   • AOrgan
   • BTissue
   • COrgan system
   • DOrganism

   (b)

   Which of these correctly describes the level of biological organisation that is immediately above a tissue in a multicellular organism?

   [1 mark]

   • ACell
   • BMolecule
   • COrgan system
   • DOrgan

   (c)

   The onion bulb is described as an organ. Using the information given, explain why the onion bulb can be classed as an organ rather than a single tissue.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   The human stomach is an organ involved in digestion. It contains muscular tissue, which contracts to churn food and mix it with digestive juices; glandular tissue, which produces enzymes and hydrochloric acid; and epithelial tissue, which lines the stomach and protects it from being digested by its own acid. The stomach works together with the mouth, oesophagus, small intestine and large intestine as part of a larger system that breaks down and absorbs food.

   (a)

   Which term best describes the stomach, given that it is made from several different tissues working together to carry out a specific function?

   [1 mark]

   • ACell
   • BTissue
   • COrgan
   • DOrgan system

   (b)

   Which term best describes the group of organs, including the stomach, that work together to digest and absorb food?

   [1 mark]

   • AOrgan system
   • BTissue
   • CCell
   • DOrganelle

   (c)

   Using the information given, explain how the muscular tissue and glandular tissue in the stomach work together to help digestion.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A patient receives a heart transplant to replace a heart that has been severely damaged by disease. The heart is made of cardiac muscle tissue, which contracts to pump blood, as well as nervous tissue and connective tissue that hold the structure together. The heart works as part of the circulatory system, which also includes blood vessels and blood, to transport substances around the whole body.

   (a)

   Using the example of the heart, describe the levels of organisation from cell to organ system in a multicellular organism.

   [3 marks]

   (b)

   Explain why the heart needs more than one type of tissue to function effectively as a pumping organ.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Marfan syndrome is a genetic disorder that affects the connective tissue found throughout the body. Connective tissue normally provides strength and support to organs such as the heart and blood vessels, as well as to the skin and skeleton. In a person with Marfan syndrome, the connective tissue is weaker than normal, which can affect the structure and function of organs and organ systems throughout the body.

   (a)

   Using the information given, and your knowledge of the levels of biological organisation, explain how a fault at the cell level, in this case a faulty gene affecting connective tissue, can lead to problems at the level of organs and organ systems.

   [6 marks]

   (b)

   Evaluate the importance of the hierarchical organisation of cells, tissues, organs and organ systems for the efficient functioning of a multicellular organism such as a human.

   [6 marks]

   Total for question 4: 12 marks

End of questions