B2.1 (Cell division) Flashcards
Why are new cells needed
For growth and repair
What is a gene
A small packet of information that can controls a characteristic or part of a characteristic
How many chromosomes are in the human body
46 (23 pairs )
How many chromosomes does a gamete have
23 chromosomes
What is a chromosome
thread-like structures located inside the nucleus of animal and plant cells
What is the cell cycle
Series of stages in which body cells divide
What is mitosis
cell division which produces two identical daughter cells
What are the three cell cycle phases
Interphase , Mitosis , Cytokenisis
What happenes during interphase
DNA in chromosomes copies itself , cells grows , Sub-celluar structures number increase
what are the stages of mitosis
prophase , metaphase , anaphase , telophase
What happens in prophase
Dna in chromosome condense , membrane around nucleus dissapears
What happens during metaphase
Chromosomes and their copies line up in the middle of the cell.
What happens during anaphase
Chromosomes and their copies are pulled to different ends of the cell.
What happens during telophase
New membranes form around the chromosomes at each end of the cell.
What happens during cytokenisis
The cell membrane pinches in and eventually divides into two daughter cells.
