B2 - Cells and Control Flashcards
Define
chromosone.
a coiled up length of DNA molecules
What is a
diploid cell?
a cell which has two copies of each chromosone
What is
mitosis
used for?
- growth in multicellular organisms
- replacing cells that have been damaged in multicellular organisms
Define
asexual reproduction.
the use of mitosis to reproduce
What are the
main stages of the cell cycle?
(6 stages)
International - Interphase
Propaganda - Prophase
Makes - Metaphase
Animals - Anaphase
Telecommunicate - Telophase
Cylently - Cytokinesis
What occurs during
interphase?
(2 things)
- the cell grows and increases the amount of subcellular structures (e.g. mitochondria and ribosomes)
- the DNA is duplicated and forms X-shaped chromosones
each ‘arm’ (chromatid) of the chromosone is an exact duplicate of the other
What are the
four stages of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
What occurs during
prophase?
(2 things)
- the chromosones condense, getting shorter and fatter
- the membrane around the nucleus breaks down and the chromosones lie free in the cytoplasm
What occurs during
metaphase?
(1 thing)
the chromosones line up at the centre of the cell
What occurs during
anaphase?
- spindle fibres pull the chromosones apart
- the chromatids are pulled to opposite ends of the cell
What occurs during
telophase?
(2 things)
- membranes form around each of the sets of chromosones
- cytokinesis occurs
these become the nuclei of the two new cells - the nucleus has divided
What occurs during
cytokinesis?
the cytoplasm and cell membrane divide to form two separate cells
(this is part of telophase)
What is produced at the end of
mitosis?
two genetically identical diploid daughter cells which are genetically identical to the parent cell
