Unit 1 - KA 1 Flashcards
(18 cards)
What are somatic cells?
Any cell in the body other than those involved in reproduction
What are germline cells?
Cells involved in reproduction
Are somatic cells haploid or diploid?
Diploid (contains 2 sets of chromosomes)
What do somatic cells divide by?
Mitosis
What do germline cells divide by?
Mitosis and meiosis
What is mitosis?
Cell division that maintains the diploid chromosome number and is used for growth and repair.
What is meiosis?
Cell division used in haploid gamete production
What are the 2 divisions in meiosis?
Firstly separating homologous pairs of chromosomes in daughter cells and secondly separating pairs of chromatids to produce haploid gametes
What is cellular differentiation?
Process by which a cell switches on certain genes to express proteins characteristic to that type of cell and other genes in the cell are switched off and so are not expressed
Can differentiated cells carry out a specialised function?
Yes
What are stem cells?
Unspecialised somatic cells that can divide to make copies of themselves and to make cells that differentiate into specialised cells of one or more types.
What are the two types of stem cells?
Tissue and embryonic
What are tissue stem cells?
They are multipotent, they are involved in the growth, repair and renewal of the cells in that tissue type
What are embryonic stem cells?
In the very early embryo are pluripotent, they can differentiate into all cell types that make up the individual. Genes from embryonic stem cells have the potential to switched on or off
What are the uses of stem cells?
Repair of damaged or diseased organs or tissues used for things such as skin grafts and corneal repairs. They can be used as model cells and can ve used to test the effectiveness of drugs on cells in general
What are the ethical issues with stem cells?
By using embryonic stem cells for therapeutic uses this involves the destruction of the early embryo
What are cancer cells and how do they divide?
Abnormal cells in the body which no longer respond to regulatory signals this causes them to divide excessively forming a tumour
How is a secondary tumour formed?
Cells within the tumour may fail to attach to each other spreading through the body
