Flashcards in 1.1. Division and Differentiation of Human Cells Deck (20):
What are the four levels of organisation in our bodies?
Cells -> Tissue -> Organs -> Systems
What are stem cells?
They are unspecialised cells that have the ability to self renew and differentiate into a diverse range of specialised cells.
What does pluripotent mean?
Able to differentiate into most of all cell types. (Embryonic stem cells)
What does totipotent mean?
Able to differentiate into all cell types.
What does multipotent mean?
Able to differentiate into closely related cells. (Tissue stem cells)
What is an ethical issue to do with stem cells?
When doing research on stem cells it involves the destruction of the embryo. People see embryos as potential life so destroying a potential life is seen as unethical.
What are somatic cells?
Cells derived from the differentiation of stem cells. They form several types of body tissue.
How are somatic cells produced?
They are produced through cellular differentiation where a cell develops more specialised functions by expressing the specific genes needed for each cell type.
What are germline cells?
They include gametes and the cells that produce the gametes (gamete mother cells).
What are genes?
The basic unit of inheritance, many of which make up a chromosome; each carries the information needed to make a protein.
What are chromatids?
One of the two identical replicas of a chromosome.
What does diploid mean?
Has a double set of chromosomes which form cells.
What does haploid mean?
Has a single set of chromosomes.
Describe the process of mitosis.
Chromosomes appear in the nucleus, the chromosomes then shorten and appear as double threads joined at one point. The membrane around the nucleus disappears and the chromosomes line up at the centre of the cell. The chromatids are pulled apart and move to opposite sides of the cell. The nuclear membrane reforms round each group of chromatids and the cytoplasm divides. The two new cells now undergo a growth period before mitosis starts again in each cell.
Describe the process of meiosis.
A diploid cell with 4 chromosomes exists. The chromosomes then replicate to make 4 identical copies of themselves where homologous chromosomes pair up and swap sections of DNA. The homologous pairs then line up at the centre of the cell and divide into daughter nuclei. The chromosomes then divide once more producing four haploid gametes.
Which cells fall under the connective tissue category and why?
Blood cells, bone cells, cartilage cells, connect tissue together, located in between other tissue.
Which cells fall under the epithelial tissue category and why?
Cells that line organs and skin cells, they line tubes, cavities and surfaces of structures throughout the body.
Which tissue makes up most of the muscles in the body such as skeletal muscle, heart muscle?
Which tissue makes up the nervous system?