Biology 9700 · AS & A Level · Testing for biological molecules
Testing for biological molecules — practice question
How the human body responds to tissue damage depends on which tissues are involved. Epithelial tissue, liver tissue and cardiac muscle tissue each react differently when they are damaged. Epithelial tissue in the gas exchange system contains stem cells. Liver tissue contains cells that are not dividing but can re-enter the cell cycle when stimulated. Cardiac muscle tissue contains cells that are unable to divide at all. The damage is permanent and is linked to scar tissue formation.
(a)[2]
Explain the significance of mitosis in repairing damaged tissue.
(b)[2]
Explain why stem cells are important in tissue repair.
(c)[3]
After liver tissue is damaged, chemicals are made and released into the bloodstream. These chemicals stimulate the liver cells to assist tissue repair. Explain how this shows cell signalling.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Mitosis makes new/daughter cells to replace damaged or dead cells” …