Cell Biology: Cell Division Flashcards
How is genetic information stored in the nucleus of a cell?
Chromosomes are contained inside the cell’s nucleus . These are long, thin, threadlike structures made from molecules of DNA that store genetic information. Chromosomes are found in the nucleus of body cells in pairs - one chromosome is inherited from the mother and one is inherited from the father.
What is the process that happens during the cell cycle, including mitosis?
- Cell begins to divide
- The DNA replicates to form two copies of each chromosome
- Chromosomes line up at the centre of the cell
- Pulled to each end of the cell and the nucleus divides
- Cytoplasm and cell membrane divides to form two identical cells
What is the process of making stem cells?
An embryo develops from a fertilised egg. Cells at the early stages in the development of the embryo are stem cells.
If cells are removed from the embryo – called embryonic stem cells - they will differentiate into any cell type.
Some stem cells remain in the bodies of adults – adult stem cells. Adult stem cells are found in limited numbers at certain locations in the body.
Where can adult stem cells be found in the body?
brain eyes blood heart liver bone marrow skin muscle
Describe stem cells in plants
Cell division in plants occurs in regions called meristems.
Cells of the meristem can differentiate to produce all types of plant cells at any time during the life of the plant.
The main meristems are close to the tip of the shoot, and the tip of the root.
What are stem cells like in plants vs animals?
Embryonic stem cells are important as they help to form all of the different tissues and organs needed during development to form a new individual
The role of adult stem cells is predominantly to replace cells lost through damage or to produce new cells for growth – although the bone marrow has to continually make new blood cells throughout life
In plants, meristem cells are unspecialised cells which can differentiate into the cells needed by the plant in regions where growth is occurring
For example, meristem cells in the roots can differentiate into root hair cells as well as other cells required in this part of the plant
The stem cells found in the meristems of plants retain the ability to differentiate into any type of plant cell throughout the life of the plant
What is therapeutic cloning?
Therapeutic cloning could produce stem cells with the same genetic make-up as the patient.
The technique involves the transfer of the nucleus from a cell of the patient, to an egg cell whose nucleus has been removed.
List the issues with therapeutic cloning
Clinical issue:
- There is no guarantee how successful these therapies will be, for example the use of stem cells in replacing nerve cells lost in Parkinson’s disease patients.
Ethical issue:
- embryos could come to be viewed as a commodity, and not as an embryo that could develop into a person.
Social issue:
- Educating the public about what stem cells can, and can’t do, is important.
