Unit 1-Division And Differentiation In Human Cells Flashcards
What are somatic cells?
Any cell in the body other than cells involved in reproduction.
Process by which somatic cells divide
Somatic cells divide by mitosis
Cells produced by mitosis
Identical daughter cells
Why is it important that somatic cells divided by mitosis?
Daughter cells obtain all of the genetic info they need to function or no genetic info is lost or to maintain the diploid chromosome number.
Why do somatic cells divide?
For growth and repair to maintain the total number of cells.
What are examples of somatic cells?
Red blood cells, muscle cells, and hair cells, etc.
(All body cells of an organism – apart from the sperm and egg cells)
What are germline cells?
Cells in the sexual organs that produce sperm and eggs.
How do germline cells divide to produce more germline cells?
By mitosis.
What are examples of gametes?
Sperm and egg.
Process by which germline cells divide to produce gamete cells?
By meiosis.
Meaning of haploid and diploid
Haploid contains one set of chromosomes.
Diploid contains two sets of chromosomes.
What is the main difference between Meiosis and Mitosis?
Meiosis
2 rounds of cell division to produce 4 genetically different haploid daughter cells.
Mitosis
1 round of cell division to produce 2 genetically identical diploid cells.
What are stem cells?
Unspecialised somatic cells which can divide to make copies of themselves and/or differentiate into specialised cells.
What is Cellular Differentiation?
A cell expresses certain genes to produce proteins characteristic for that type of cell.
Allows cells to carry out specialised functions.
Difference between pluripotent and multipotent
Pluripotent can give rise to all types of cell.
Multipotent can differentiate into any of the types of cell of the same tissue type.
Are adult tissue stem cells capable of dividing into a wide range of differentiated cells?
No (multipotent)
Are embryonic stem cells capable of dividing into a wide range of differentiated cells?
Yes (pluripotent)
Why does adult tissue need stem cells?
To maintain cell numbers, by repairing/replacing damaged cells within tissues or organs
Term for cells that can differentiate into any specialised cell type?
Pluripotent
Are cells in the very early embryo pluripotent or multipotent?
Pluripotent
Where are adult tissue stem cells found?
Adult tissue stem cells are found in the tissue of adults and children, including the brain skin and bone marrow.
Where are embryonic stem cells found?
In the inner cell mass of early embryos around 4-5 days.
Where is the location of the tissue stem cells which develop into blood cells?
Bone marrow
What can stem cell research be used for?
Providing info on how cell processes work
Drug testing
Researching diseases
Therapeutic uses of stem cells
Repair of damaged or diseased organs or tissues
(skin graft for burn victims)
In a developing embryo, how are tissues such as muscle and nerve produced?
By somatic cells dividing by mitosis
After meiosis are the daughter cells genetically identical or different?
Different
After mitosis are the daughter cells genetically identical or different?
Identical
Are gametes diploid or haploid?
Haploid
Describe how cancer can develop and spread through the body?
Cancer cells divide excessively because they do not respond to regulatory signals and therefore the cells don’t die. This results in a mass of abnormal cells called a tumour.
Describe how division of a diploid cell by meiosis produces haploid gametes?
Each chromosome makes a copy of itself.
Pairs of chromosomes line up together then cell divides.
The two new cells immediately divide again producing 4 cells with a single set of chromosomes.
How many chromosomes do diploid cells have?
46
How many chromosomes do haploid cells have?
23
How many pairs of chromosome do germline cells have?
23 pairs of homologous chromosomes.
What is each of the 4 parts of the ‘X’ shape of the chromosome called?
The chromatids
What is the very centre of the chromosome called?
The centrome
