Unit 1: Human Cells - Key Area 1 - Division and differentiation in human cells Flashcards
What are somatic cells?
Any cell in the body other than cells involved in reproduction.
How do somatic cells divide and why is this important?
Somatic cells divide by mitosis. This is so that the daughter cells obtain all of the genetic info they need to function and no genetic info is lost. To maintain the diploid chromosome number.
Why do somatic cells divide?
Somatic cells divide for growth and repair to maintain the total number of cells.
What are examples of somatic cells?
All body cells of an organism – apart from the sperm and egg cells, like red blood cells, muscle cells, and hair cells, etc.
What are germline cells?
Haploid gametes (Sperm and Ova)
How do germline cells divide to produce more germline cells?
By mitosis.
How does a germline cell divide to produce gamete cells?
By meiosis.
What is the main difference between Meiosis and Mitosis?
In Meiosis the daughter cells undergo 2 rounds of cell division to produce 4 genetically different haploid daughter cells. But in Mitosis the daughter cell only undergoes 1 round of cell division to produce 2 genetically identical diploid cells.
What are stem cells?
Unspecialised somatic cells which can divide to make copies of themselves and/or differentiate into specialised cells.
What is Cellular Differentiation?
It is the process by which a cell expresses certain genes to produce proteins characteristic for that type of cell. This allows a cell to carry out specialised functions.
Are adult tissue stem cells capable of dividing into a wide range of differentiated cells?
No they are only capable of dividing into a limited range of differentiated cells.
Are embryonic stem cells capable of dividing into a wide range of differentiated cells?
Yes as they are pluripotent.
Why does adult tissue need stem cells?
To maintain cell numbers, by repairing/replacing damaged cells within tissues or organs
What are adult tissue stem cells involved in and why is this?
Adult tissue stem cells are involved in the growth, repair, and renewal of the cells found in that tissue. They are multipotent.
Why are embryonic stem cells capable of differentiating into any specialised cell type?
They are pluripotent.
Why are cells in the very early embryo pluripotent?
Cells in the very early embryo can differentiate into all the cell types that make up the individual and so are pluripotent.
What do differentiated cells only have a few of and what does this mean for the cell?
Differentiated cells only have a few genes switched on. So those that are not required for the function of that specific cell are switched off, meaning only the proteins that the cell requires to function are produced.
What can stem cell research be used for?
- Providing info on how cell processes work.
- Drug testing
- Researching how diseases work
What do the therapeutic uses of stem cells include?
Therapeutic uses involve the repair of damaged or diseased organs or tissues. For example, using them as a skin graft for burn victims.
In a developing embryo, how are tissues such as muscle and nerve produced?
By somatic cells dividing by mitosis
After meiosis are the daughter cells genetically different?
Yes
After mitosis are the daughter cells genetically different?
No the are identical
Are germline cells diploid or haploid?
Diploid
Describe how cancer can develop and spread through the body?
Cancer cells divide excessively because they do not respond to regulatory signals and therefore the cells don’t die. This results in a mass of abnormal cells called a tumour.
