Mitosis and Meiosis Flashcards
How do you spell mitosis?
M- I- T-O-S-I-S
How do you spell meiosis?
M-E-I-O-S-I-S
What is mitosis?
Mitosis is a type of cell division, it is when a cell reproduces itself by splitting to form two genetically identical offspring.
What is mitosis for?
making new cells for growth and repair
What type of reproduction is mitosis?
a-sexual reproduction because there is NO VARIATION
Describe the process of mitosis.
- cells get a signal to divide
- The cell duplicates its DNA so there is one copy for each new cell.
- The DNA is copied and form x-shaped chromosomes. Each arm of the chromosome is an exact duplicate of the other.
- The chromosomes line up at the centre of the cell and cell fibres pull them apart. The two arms of each chromosomes go to opposite ends of the cell.
- Membranes form around each of the sets of chromosomes- these become the nuclei of the two new cells.
- Cytoplasm divides
What is Meiosis?
Meiosis is a type of cell division that produces cells with HALF the normal number of chromosomes- they produce 23 rather than 46.
What is meiosis for?
producing gametes- sperm and egg cells
What type of reproduction is meiosis?
sexual reproduction because the offspring are GENETICALLY VARIED
Describe the process of meiosis.
- The cell duplicates its DNA before division begins. One arm of each chromosome is an exact copy of the other arm.
- In the first division, the chromosome pairs line up in the centre of the cell.
- The pairs are then pulled apart so each new cell only has one copy of each chromosome. During this process the cells randomly touch so the new cell is a mix of the father’s chromosomes and the mother’s chromosomes.
- In the second division the chromosomes line up again in the centre of the cell. The arms of the chromosomes are pulled apart.
5/ Yo get four gametes each with only a single set of chromosomes.