division & differentiation in human cells Flashcards
why is cell division necessary?
to replace damaged or dead cells.
how many chromosomes do humans normally have?
46
what is a diploid cell?
a cell with 2 sets of chromosomes. the chromosomes are organised in to 23 matching pairs.
what is a somatic cell?
a diploid body cell that can only divide by mitosis
what process do somatic cells divide by?
mitosis
when somatic cells divide what type of cells do they form?
they form diploid daughter cells that are identical to the parent cell.
what is a germline cell?
a diploid cell which will lead to the formation of a gamete (sex cell)
where are germline cells found?
the testes & overies.
what process do germline cells divide by?
they divide by both mitosis to produce new diploid germline cells or by meiosis to produce haploid gametes.
describe a germline cell process of dividing by meiosis.
the nucleus of a germline stem cell undergoes 2 divisions, firstly separating homologous (matching) chromosomes and secondly secondly separating chromatids.
what is cellular differentiation?
when a a cell expresses certain genes to produce protein charcterisitcs of the cell its becoming. this allows it to carry out that function
what happens during cellular differentiation?
a cell will express certain genes to produce protein characteristics for the tpe of cell its becoming. this allows it to carry out that specific function.
embryonic stem cells can differentiate into any type of cell, what is the term to describe this?
pluripotent
how can an embryonic stem cell differentiate into any type of cell?
because all the genes in an embryonic stem cell can be switched on.
tissue stem cells can differentiate into all the types of cell found in a particular tissue type, what is the phrase to describe this.
multipotent
