Cell organisation: tissues, organs and systemsEdexcel A-Level Biology A: Subtopic test

1. 1
   The wall of the small intestine is made of several types of cell. The inner lining is a layer of epithelial cells with microvilli that absorb nutrients. Beneath it is connective tissue containing blood vessels, and around the outside are layers of smooth muscle that contract to move food along.

   (a)

   Which term best describes the small intestine?

   [1 mark]

   • AAn organ
   • BA tissue
   • CAn organ system
   • DAn organelle

   (b)

   The small intestine, stomach, liver and pancreas all contribute to digestion. Together, what do they form?

   [1 mark]

   • AA tissue
   • BAn organ
   • CAn organ system
   • DAn organelle

   (c)

   Explain why the small intestine is an organ rather than a tissue.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A leaf from a privet shrub has an upper epidermis, a layer of palisade mesophyll, a layer of spongy mesophyll, vascular bundles containing xylem and phloem, and a lower epidermis with stomata surrounded by guard cells.

   (a)

   Which tissue is the main site of photosynthesis in the leaf?

   [1 mark]

   • AXylem
   • BUpper epidermis
   • CPhloem
   • DPalisade mesophyll

   (b)

   Which of the following is a tissue and not an organ?

   [1 mark]

   • ALeaf
   • BXylem
   • CRoot
   • DFlower

   (c)

   Explain the advantage to a large multicellular plant of having its cells organised into specialised tissues.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   The wall of the stomach contains glandular epithelium, whose cells secrete hydrochloric acid, the enzyme pepsin and mucus. It also contains layers of smooth muscle, connective tissue with blood vessels, and nervous tissue.

   (a)

   Describe how cells are organised into an organ system, using the stomach as an example.

   [3 marks]

   (b)

   Explain how the tissues in the stomach wall work together to digest protein.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Surgeons are developing a laboratory-grown replacement for a damaged section of the trachea (windpipe). In a natural trachea the inside is lined by ciliated epithelial cells and goblet cells, and the wall contains smooth muscle, rings of cartilage and connective tissue containing blood vessels. The trachea carries air to the lungs as part of the gas exchange system.

   (a)

   Explain why a layer of cultured epithelial cells alone could not replace a damaged section of trachea.

   [6 marks]

   (b)

   Describe how cells in the airways are organised into tissues, organs and systems, and explain the advantages of this organisation for a large multicellular organism.

   [6 marks]

   Total for question 4: 12 marks

End of questions