OCR AS LEVEL JUNE 2022 BIOLOGY B PAPER 2 QUESTION PAPER

AS Level Biology B (Advancing Biology) H022/02 Biology in depthFig. 1.1 shows a prepared slide of onion cells in different stages of mitosis, viewed using a light microscope.Name the stages of mitosis taking place in c ...

AS Level Biology B (Advancing Biology) H022/02 Biology in depthFig. 1.1 shows a prepared slide of onion cells in different stages of mitosis, viewed using a light microscope.Name the stages of mitosis taking place in cells A and B.Fig. 1.3 shows the cell cycle in an onion cell.The cell cycle is controlled by proteins. These proteins can initiate apoptosis. Describe the sequence of events that occurs during apoptosis.Lenticels appear as small brown patches on the surface of some fruit. A researcher wanted to investigate if water availability affected the number of lenticels on the surface of apples. They chose nine apple trees of one variety and watered each tree with a specific volume of water every day for twelve weeks. After twelve weeks they counted the total number of lenticels that developed on the surface of one apple from each tree. This was repeated with a second variety of apple. Fig. 2.1 shows the number of lenticels found on the surface of the two varieties of apple.Using only Fig. 2.1, what conclusions can be drawn about the effect of water availability on lenticel number for these two varieties of apple?Another researcher suggested that: ‘Adding a known volume of water to the tree is not a suitable method of investigating the effect of water availability on lenticel development.’ Evaluate this claim.The researcher compared the number of lenticels on apples of each variety. A more accurate method would be to compare the density of lenticels per apple. Suggest how the researcher could measure lenticel density and explain why this would be a more accurate way to compare the effect of water availability on the two varieties. You can assume that the apples are spherical.