Cell Division (MITOSIS & MEIOSIS) Flashcards
State the definition of Cell Division
New cells are produced by old cells dividing.
What is the purpose of Mitosis?
Growth and repair of body cells
What is the purpose of Meiosis?
Production of Specialised Sex Cells
What is Ploidy?
Refers to the number of complete sets of chromosomes in a cell or organism.
Diploid (2n)
Haploid (n)
What is a Homologous Chromosome?
Chromosomes of the same size and shape that carry the same type of genes
What is a Chromatid?
One of the two duplicated chromosomes connected at the centromere
What is a Centromere?
Region of chromosome where microtubules attach during mitosis and meiosis
What in the nucleus carries the genetic material and what is it made out of?
Chromosomes made out of protein and single molecule of deoxyribonucleic acid
The Cell Cycle comprises of:
Interphase:
- G1
- S
- G2
Mitosis:
- Prophase
- Metaphase
- Anaphase
- Telophase
Cytokinesis
Describe Interphase
Cell carries out normal functions but also prepares to divide
S Phase: Cell’s DNA unravelled and replicated, to double its genetic content
During G1 and G2: The organelles are also replicated so it has spare ones, and its ATP content is increased (ATP provides energy for cell division)
What is Mitosis?
Refers to the process of nuclear division that occurs before a cell physically divides in 2.
Explain what happens during Prophase
Chromosomes condense and become visible.
Centrioles move to opposite ends of cells forming network called Spindle.
Nuclear envelope breaks down and chromosomes lie in free cytoplasm
Explain what happens during Metaphase
Chromosomes line up along middle of cell.
Spindle attaches to Centromere
Explain what happens during Anaphase
Centromere divides, separating each pair of sister chromatids.
Spindle contracts pulling chromatids to opposite poles
Chromatids appear V-Shaped
Explain what happens during Telophase
Chromatids reach opposite poles on spindle.
They uncoil and become long and thin and are called chromosomes
Nuclear envelope forms again to form 2 nuclei
Cytoplasm divides and there are two identical daughter cells.