4.2 Cell division and stem cells Flashcards
What is Mitosis and what is the result?
Mitosis is Asexual Reproduction, and results in two genetically identical daughter cells. Each daughter cell has the same number of chromosomes as the mother cell.
What is Meiosis and what is the result?
Meiosis is Sexual Reproduction, and results in four sex cells. There are two stages of Division, and the resulting daughter cells have half the number of chromosomes as the mother cell.
What are stem cells?
Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair system for the body.
What are the sources of stem cells?
- Embryonic tissue
- Adult stem cells that occur in some tissue.
What are the capabilities of an Embryonic stem cell?
Embryonic stem cells can divide into more stem cells or become any type of cell in the body.
What are the capabilities of an Adult stem cell?
Adult stem cells can divide or self-renew indefinitely. They can generate various cell types from the originating organ.
What are the capabilities of a stem cell already made by yourself?
Our own stem cells can be extracted in a surgery and be used to replace blood cells destroyed by high doses of chemotherapy and other treatments.
Define DNA.
DNA, or deoxyribonucleic acid, is a chemical made up of two long molecules, arranged in a double-helix structure. This carries genetic information, which has all the instructions that a living organism needs to grow, reproduce and function.
Define Gene.
Genes code for characteristics.
Define Chromosome.
Chromosomes are linear arrangements of genes that make up DNA. Chromosomes come in pairs also, one from each parent.
Define Cancer.
Cancer is the result of uncontrolled mitosis.
Define a stem cell.
Hint: The cell has not undergone…
Stem cells are cells that have not ungergone differentiation (a cell which has not yet become specialised).
Define Phenotype.
A phenotype is the visible characteristics of an organism which occur as a result of its genes.
What is the difference between a dominant allele and a recessive allele?
The dominant allele always expresses itself whether it is partnered by a recessive allele or by another like itself, whereas a recessive allele destribes the variant of a gene for a particular characteristic which is masked or suppressed in the presence of the dominant variant.
What is the difference between a dominant allele and a recessive allele?
The dominant allele always expresses itself whether it is partnered by a recessive allele or by another like itself, whereas a recessive allele describes the variant of a gene for a particular characteristic which is masked or suppressed in the presence of the dominant variant.
