Cell Division Flashcards
What do chromosomes contain?
Genetic information
In body cells the chromosomes are normally found in pairs, how do they divide?
By mitosis
What happens when a body cell divides by mitosis?
- copies of the genetic material are made
- then the cell divides once to form two genetically identical body cells
When does mitosis occur?
During growth or to produce replacement cells?
How many sets of chromosomes do body cells have?
Two sets
How many sets of chromosomes do gametes have?
1 set
What are gametes?
Sex cells
What do cells in reproductive organs do?
Testes and ovaries in humans divide to form gametes
what is meiosis?
The type of cell division in which a cell divides to form gametes
What happens when a cell divides to form gametes?
- copies of the genetic information are made
- the cell then divides twice to form four gametes, each with a single set of chromosomes
What are genetic diagrams?
Biological models which can be used to predict the outcome of crosses
What happens when gametes join at fertilisation?
A single body cell with new pairs of chromosomes is formed
A new individual then develops this cell repeatedly by dividing by mitosis
What is the difference between plant cells and animal cells?
Animal cells differentiate at an early stage
Plant cells retain the ability to differentiate throughout life
What happens in mature animals?
Cell division is mainly restricted to repair and replacement
What are stem cells?
Cells from human embryos and adult bone marrow
What can stem cells do?
They can be made to differentiate into many different types of cells (nerve cells)
What do human stem cells have the ability to do?
Develop into any kind of human cell
What can stem cells be used for?
Treatment with stem cells may be able to help conditions such as paralysis
What are the cells of the offspring produced by asexual reproduction produced by?
Mitosis from parental cells
What do parental cells contain?
The same alleles as the parents
