Unit 1 - Human Cells Flashcards
what is a somatic cell
a somatic cell is any cell which is not involved in reproduction
what do somatic cells divide by and what do they form through this
somatic cells divide by mitosis to form more somatic cells
what are germline stem cells
germline stem cells are gametes (sperm and ova), they are also the stem cells which divide to form gametes
what can germline stem cells divide by
germline stem cells divide by mitosis and meiosis
what do germline stem cells produce as they divide by mitosis
when germline stem cells divide by mitosis they form more germline stem cells
why do germline stem cells divide by mitosis
they divide by mitosis to maintain the diploid chromosome number
how many pairs of homologous chromosomes do diploid cells contain
diploid cells contain 23 pairs of homologous chromosomes
what does division by meiosis produce
haploid gametes
how many divisions are needed in meiosis
2 divisions are needed
what are the 2 divisions of meiosis
the first division separates homologous chromosomes and the second division separates chromatids
how many chromosomes are present in a haploid cell gamete
23 single chromosomes are present in a haploid cell
what is cellular differentiation
cellular differentiation 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
define pluripotent
pluripotent cells are cells which can differentiate into all the cell types that make up an individual cell.
are embryonic stem cells multipotent or pluripotent
stem cells are pluripotent meaning they can differentiate into all the cell types that make up an individual cell
what are special about the genes in an embryonic stem cell
all the genes are switched on so they can differentiate into any type of cell
what are tissue stem cells involved in
tissue stem cells are involved in growth, repair and renewal of cells found in that tissue
are tissue stem cells multipotent or pluripotent
tissue stem cells are multipotent as they can only differentiate into cells found within that tissue
where are blood stem cells located
they are located in bone marrow
what can stem cells located in bone marrow produce
red blood cells, phagocytes, lymphocytes and platelets
what does the therapeutic use of stem cells involve
the therapeutic use of stem cells include the repair of damaged or diseased organs or tissues
what are examples of therapeutic uses of stem cells
regeneration of damaged skin and the repair of the cornea
what is stem cells involvement in research
they are involved by being used as model cells to study how diseases develop or used as model cells for drug testing
what can happen in the right conditions to embryonic stem cells in a lab
embryonic stem cells are able to self renew under the right conditions in a lab
what information can stem cells provide
stem cells can provide information on how cells processes such as growth, differentiation and gene regulation work
what is ethical issue of embryonic stem cells
embryonic stem cells can offer effective treatment of diseases and injury however, it involves the destruction of embryos
why do cancer cells divide excessively
cancer cells divide excessively because they do not respond regulatory signals
what is a mass of abnormal cells called
a mass of abnormal cells is called a tumour
what happens when cells within the tumour fail to attach to each other
the cancer cells will spread throughout the body where they might create a secondary tumour
