b1 Chromosomes and mitosis Flashcards
(6 cards)
What are chromosomes
Coiled up lengths of DNA molecules
What do different genes control
Develop of different characteristics for example hair colour
What do body cells have
Two copies of each chromosome one from mother and one from father
How many chromosomes are there
23 pairs
How does growth and DNA replication work
DNA spreads out along strips
Before advise as to grow and increase all sub cellular structures
Duplicate the DNA
The DNA copy forms identical X shaped chromosomes
How does mitosis work
After the process of growth and DNA replication:
Chromosomes lineup in the centre of the cell And cell fibres pull them apart
Membranes form around each set of chromosomes this becomes the nuclei
Cytoplasm and cell membrane divide
Two identical daughter cells are produced
