1.1 Flashcards
(25 cards)
what are somatic cells
•any cell in the body other than gametes
describe somatic cells and what they do
•somatic cells are diploid and divide by mitosis to form more diploid somatic cells
why are somatic cells useful?
•important for growth and repair
(mitosis=more diploid somatic cells)
describe what happens during mitosis in somatic cells
•during mitosis two identical daughter somatic cells are produced, each with the same number of chromosomes as the original parent cell
•the diploid chromosome complement is maintained
(23 pairs of homologous chromosomes)
what are germline cells
•germline cells are gametes and the stem cells that divide to form gametes
describe germline cells and what they do
•germline cells are diploid and divide by mitosis to form two identical daughter germline cells
•diploid chromosome complement is maintained
(23 pairs of homologous chromosomes)
•these daughter cells then divide further by meiosis
what happens during meiosis
•during meiosis, four haploid gametes are produced, each with only one set of chromosomes
(23 single chromosomes)
•the diploid chromosome complement is not maintained as the cells produced are haploid
describe cellular differentiation and its process
•cellular differentiation is a process in which a cell expresses certain genes to produce the proteins which are characteristic for that cell type
what does cellular differentiation allow cells to do
•allows the cell to carry out specialised functions
what are stem cells?
•unspecialised cells that can self-renew or differentiate i to specialised cells
what are the two types of stem cells?
•embryonic stem cells
•tissue stem cells
describe embryonic stem cells
•found in a very early embryo
•embryonic stem cells have all of their genes ‘switched on’ so they can differentiate into all cell types that make up an individual
what are embryonic stem cells said to be
•pluripotent
(can differentiate into any cell in the body)
what are embryonic stem cells said to be
•pluripotent
(can differentiate into any cell in the body)
describe tissue stem cells
•found un particular tissues and organs throughout the body
•tissue stem cells can only differentiate into the cell types found in the particular tissues where they are found
what are tissue stem cells said to be
•multipotent
(can differentiate into a limited amount of cells)
what are tissue stem cells involved in
•growth
•repair
•renewal of the cells found in that tissue
what can cause embryonic stem cells to self-renew
•can self-renew under the right conditions in the lab
stem cells are used as model cells to:
•provide information on how cell processes such as: gene-regulation, cell growth and differentiation work
•study how diseases and disorders develop
•test the responses of cells to new drugs
what do therapeutic uses of stem cells involve
•repair of damaged or diseased organs/tissues
what do therapeutic uses of stem cells include?
•stem cell skin grafts
(cultured skin stem cells are sprayed onto damaged skin to regenerate it)
•corneal repairs
(cultured corneal stem cells are placed over damaged cornea to regenerate it)
what are cancer cells and what do they do?
•cancer cells do not respond to regulatory signals that control cell division
•therefore they divide excessively to form a mass of abnormal cells called a tumour
what are benign tumours
•benign tumours remain in one place and do not spread throughout the body
what are malignant tumours?
•secondary tumours
