Diagram 5.1 shows a cell cycle.
(a)(i) State the names of phases X and Z. [2 marks]
(ii) State what happens to the chromosome during phase Y. [1 mark]
(b) Diagram 5.2 shows the cytokinesis that occurs in the animal cell and the plant cell.
Complete Diagram 5.2 by drawing stages of cytokinesis in the spaces provided. [2 marks]
(c) Diagram 5.3 shows a technique in biotechnology that is using mitosis.
(i) State the technique used in Diagram 5.3. [1 marks]
(ii) The technique is used widely in the agriculture field to produce tomato plants rather than sowing seeds. Explain the benefits of the technique used for growing tomato plants. [2 marks]
Answer:
(a)(i)
X : Interphase
Z : M Phase
(a)(ii)
1: DNA synthesis / replication
2: Chromosomes double / duplicate // become two identical/twin chromatids
(b)
(c)(i) Tissue culture
(c)(ii)
1: (Plantlet) can be generated more quickly.
2: (Plantlet) can be produced in large quantities
3: (Plantlet) can be produced throughout the year // not affected by weather//does not require seeds
4: Good characteristics of the parent can be maintained
5: No variation // Same genetic content