Author Topic: EDEXCEL - SPECIMEN 6BIO2  (Read 895 times)

Offline moon

  • SF Citizen
  • ***
  • Posts: 222
  • Reputation: 770
EDEXCEL - SPECIMEN 6BIO2
« on: May 06, 2010, 08:38:59 pm »
please can u help in this question:

Describe how a cell loses the ability to produce other cell types and becomes specialised.

Offline anachronism

  • Newbie
  • *
  • Posts: 36
  • Reputation: 834
Re: EDEXCEL - SPECIMEN 6BIO2
« Reply #1 on: May 06, 2010, 09:32:00 pm »
It [the cell] undergoes differential gene expression.

1. ref to correct stimulus e.g. chemical ;
2. some genes {switched off / switched on / eq}
;
3. mRNA from {switched on / eq} genes ;
4. mRNA translated / eq ;
5. idea of {protein synthesised / different
proteins produced} ;
6. which (permanently) modify cell (to become
specialised) /description of a modification /
eq ;

It's just that a certain time in the cell's life, chemicals that switch on or switch off certain genes are released. As you know, your genes are used to make proteins. The mRNA from these switched off/on genes undergoes transcription and then translation [in protein synthesis] and various proteins are produced. These proteins will permanently modify the cell and it can then become specialised.

To test you knowledge, try suggesting how sperm cells become specialised.