5 max
IB BANK BIO VERSION 3
MUHD INAAMULHASAN BIN SATHAR MOHD 2012-2014
(Plus up to [2] for quality)
[20]
12.
The electron micrograph below shows the ultrastructure of part of an animal cell.
[Source: Reproduced with the kind permission of the Electron Microscopy Facility, Trinity College, Hartford, Connecticut, USA, and Professor Daniel G. Blackburn.]
(a) 12. (a) (b)
Identify the structure labelled I. rough endoplasmic reticulum/RER/rough ER / ribosome 1
Explain briefly how materials produced in the structure labelled I are …show more content…
growth/production of (extra) body cells; (do not accept cell growth) first stage of spermato/oo/gametogenesis / forming oogonia/spermatogonia; embryo development; wound healing / (tissue) repair / hair growth / (do not accept replacemen t of skin cells; repairing cells) clonal selection / division of lymphocytes (for antibody production); Do not accept asexual reproduction. Do not award a mark if one of the first two answers is incorrect. 1 max (c) (c) Describe the importance of stem cells in differentiation. stem cells are undifferentiated cells; embryo cells are stem cells; stem cells can differentiate in many/all ways / are pluripotent/totipotent; differentiation involves expressing some genes but not others; stem cells can be used to repair/replace tissues/heal wounds; The graphs below show the normal menstrual