2.7.1 Cell division Flashcards
How are chromosomes normally found?
In pairs.
How do body cells divide?
Body cells divide by mitosis.
What do chromosomes contain?
The chromosomes contain the genetic information.
What happens to the genetic material when a body cell divides?
■ copies of the genetic material are made
■ then the cell divides once to form two
genetically identical body cells.
When does mitosis happen?
Mitosis occurs during growth or to produce
replacement cells.
What is the difference in terms of chromosomes between body cell and sex cells?
Body cells have two sets of chromosomes; sex cells (gametes) have only one set.
Where and what do the cells in the reproductive organs dive to form?
Cells in reproductive organs – testes and ovaries in
humans – divide to form gametes.
What is cell division called when a cell divides to form gametes?
The type of cell division in which a cell divides to
form gametes is called meiosis.
What are 2 things that happen when a cell divides to form gametes?
■ copies of the genetic information are made
■ then the cell divides twice to form four
gametes, each with a single set of
chromosomes.
What happens in fertilization in relation to chromosomes?
When gametes join at fertilisation, a single body cell
with new pairs of chromosomes is formed. A new
individual then develops by this cell repeatedly
dividing by mitosis.
What are stem cell and where can we find them and what do they do?
Cells from human embryos and adult bone marrow,
called stem cells, can be made to differentiate into
many different types of cells, eg nerve cells.
What kind of cells can stem cells develop into?
Human stem cells have the ability to develop into
any kind of human cell.
What can stem cells be used to treat?
Treatment with stem cells may be able to help
conditions such as paralysis.
What is mitosis?
The cells of the offspring produced by asexual
reproduction are produced by mitosis from the
parental cells. They contain the same alleles
as the parents.
