1.1 Division and differentiation in human cells Flashcards
what is a somatic cell?
any body cell other than a cell involved in reproduction.
What is a germline cell?
haploid gametes(sperm and ova) and the stem cells that divide to form gametes.
what is a stem cell?
An unspecialised cell is an unspecialised somatic cell which can divide to make copies of itself/differentiate into specialised cells.
Name the cells which divide by mitosis
gemerline - divide to form more diploid germline cells
Somatic - divide to form more diploid somatic cells
Name the cells which divide by meiosis.
Germline cells divide by meiosis to produce gametes.
what is cellular differentiation?
Is the process by which a cell expresses certain genes to produce specific proteins. This allows the cell to carry out specialised functions.
Name the tissues which somatic cells can form by differentiation.
epithelial - cover the entire body’s surface and line body cavities.
connective - bone and cartilage
muscle cells - form muscle tissues
nervous cells - form nerve tissues
Define the term ‘multipotent’
Cells that can only differentiate into specialised cells found within that tissue. e.g., tissue
Define the term ‘pluripotent’
all genes can be switched on so they can divide into ANY cell.
Give 2 examples of how stem cells can be used therapeutically
To repair damaged corneas
To repair and regenerate skin e.g., skin graft following a burn.
Why do stem cells raise ethical issues?
stem cells come from embryos which are destroyed which is essentially killing potential human life.
Describe the formation of a tumour.
cancer cells divide excessively as they do not respond to regulatory signals. This results in a mass of abnormal cells called a tumour.
How does a secondary tumour form?
Cancer cells within the tumour fail to attach to each other resulting in them spreading through the body.
