Cell division Flashcards
What are chromosomes?
found in pairs and contain genetic infomation
how does a body cell divide
it divides by mitosis
copies of genetic material are made
the cell divides once to form two genetically identical body cells
When is mitosis used?
used during growth or to produce replacement cells
What is the difference between the sets of chromosomes sex cells and body cells have?
gametes have 1 set
body cells have 2
How are gametes formed?
cells in reproductive organs divide to form gametes through meiosis
a cell copies the genetic information made
the cell divides twice to form four gametes, both have a single set of chromosomes
What happens when gametes join?
gametes join at fertilisation
a single body cell with new pairs of chromosomes is formed
a new individual then develops by the cell dividing by mitosis
What is the difference between division in plants and animals?
most types of animal cells differentiate at early stages
many plant cells retain the ability to differentiate throughout life
as a result, in mature animals, cell division is mainly restricted to repair and replacement
What are stem cells?
undifferentiated cell - has the ability to change into different types of cell
embryonic stem cells - can develop into all types of cells
adult stem cells - found in bone marrow, can develop into different types of blood cells
Why are stem cells used?
may be able to help conditions such as paralysis and parkinsons
How are offspring produced by asexual reproduction?
produced by mitosis from the parental cells
contain the same alleles as the parents
