DP Biology (last assessment 2024)

Test builder »

Question 23M.2.HL.TZ2.6a

Select a Test
Date May 2023 Marks available [Maximum mark: 4] Reference code 23M.2.HL.TZ2.6a
Level HL Paper 2 Time zone TZ2
Command term Explain Question number a Adapted from N/A
a.
[Maximum mark: 4]
23M.2.HL.TZ2.6a
(a)

Explain how changes to the cell cycle can result in tumour formation.

[4]

Markscheme
  1. cell cycle is (repeated) sequence of cytokinesis/cell division, (then) interphase(then) mitosis / cell cycle includes the sequence of interphase, mitosis and cytokinesis/cell division (to form new cells which repeat the cycle)
  2. cyclins control/regulate this cycle / ensure the cell moves on to the next stage of the cycle when it is appropriate
  3. extra cells produced when they are needed
  4. tumour formation is the result of uncontrolled cell division/ cells growing and dividing endlessly
  5. repeated mitoses/high mitotic index
  6. due to mutations in oncogenes / oncogenes may become active and contribute to the development of a cancer cell
  7. carcinogens/radiation/mutagenic chemicals/mutagens/smoking cause mutations/tumours;

 

Examiners report

Most answers explained tumour formation as a result of uncontrolled cell division. Even though many mentioned mutations, they often lacked the concept of oncogenes. Cyclins were considered in many responses. Many candidates failed to include cytokinesis as part of the cell cycle.

Syllabus sections