Scheme of Work Cambridge International as & a level

Extension activity: To link this topic with cell signalling (Topic 4), challenge learners to research the control of the cell cycle, including checkpoint protein kinases and the process of phosphorylation.

5.2 Chromosome behaviour in mitosis KC1 KC3

5.2.1 Describe the behaviour of chromosomes in plant and animal cells during the mitotic cell cycle and the associated behaviour of the nuclear envelope, the cell surface membrane and the spindle (names of the main stages of mitosis are expected: prophase, metaphase, anaphase and telophase). 5.2.2 Interpret photomicrographs, diagrams and microscope slides of cells in different stages of the mitotic cell cycle and identify the main stages of mitosis.

Resource Plus Carry out the Investigating mitosis by preparing a root tip squash experiment referring to the Teaching Pack for lesson plans and resources. In this task, learners prepare a root tip squash for viewing with a light microscope, in order to identify cells in different stages of mitosis. As part of this task, learners carry out activities requiring knowledge of eyepiece graticules and stage micrometers and of drawing scientifically. There are also opportunities to evaluate a range of investigation plans. Prepare seven images of cells undergoing different stages of mitosis, printed on A3 paper (ideally laminated). Ask seven volunteers to hold up one of the seven images each, so that the whole class can see. Ask the rest of the class to rearrange the volunteers in the correct order to show the process of mitosis from start to finish – and asking the first and final members to then form a circle, to emphasise that it is a cycle. Then give each member of the ‘audience’ a card that contains a description of an event during mitosis. Learners stand by the learner holding the appropriate A3 sheet. Animations can be used to reinforce this knowledge: www.cellsalive.com/cell_cycle_js.htm and www.biology.arizona.edu/cell_bio/tutorials/cell_cycle/mitosis_movie.html Prepare a written text that summarises the concepts that learners have studied in this subtopic. Include some conceptual errors such as ‘anaphase is the longest stage of mitosis’ and ‘spindle fibres attach to the telomeres during prophase.’ Learners spot and circle as many mistakes as possible, and offer corrections. (F)