Topic 12 - DNA, Protein Synthesis, and Cell Division Flashcards
Asexual reproduction
When offspring is produced from one parent through the mitosis of body cells
Gamete
A sex cell
Mitosis
A type of cell division that happens in somatic cells. The two genetically identical cells produced are diploid.
Mitosis is used for growth, repair, and asexual reproduction
- Prophase - chromosomes become visible and the nucleus disappears
- Metaphase - chromosomes line up at the cell equator
- Anaphase - chromosomes are pulled to the poles of the cell by spindles
- Telophase - the chromosomes arrive at the poles
- Cytokinesis - nucleus reforms as cells split into two
Meiosis
A type of cell division that results in genetically unique gametes. A total of four haploid daughter cells will be produced.
- Each chromosome makes identical copies of itself (forming X-shaped chromosomes)
- First division: chromosomes pair up along the equator, recombination occurs and then cell fibres will pull the pairs apart, each new cell will have one of each recombinant chromosome pair
- Second division: chromosomes will line up along the centre of the cell, cell fibres will pull them apart (as with mitosis)
Diploid
Cells that have the full number of chromosomes in homologous pairs
(body cells)
Haploid
Cells that have half the normal number of chromosomes (gametes)
Fertilisation
The fusing of the nucleus from a male gamete with the nucleus from a female gamete
Zygote
A fertilised egg
Chromosomes
A strand of DNA found in the nucleus of a cell
Parent cell
A cell that divides to produce daughter cells
Daughter cell
A cell that is produced after a parent cell divides
DNA replication
DNA producing an identical copy of itself
Clone
A genetically identical organism
Identical twins
Genetically identical twins formed from the same zygote
DNA
The chemical from which chromosomes are made