Chapter 2 - Cell Division Flashcards
How many chromosomes and pairs are found in a nucleus?
- 46 chromosomes (23 pairs)
What is the cell cycle?
- When body cells divide to form 2 identical daughter cells.
Define mitosis.
- When genetic material divide into 2 identical nuclei.
Describe the 3 stages of the cell cycle.
Stage 1 - Cells grow bigger/increased mass. Replication of DNA for cell division. Increase in number of sub-cellular structures (ribosomes, mitochondria).
Stage 2 - (Mitosis) One set of chromosomes is pulled to each end of dividing cell. Nucleus divides.
Stage 3 - Cytoplasm + Cell membrane divide to form 2 identical daughter cells.
Define gene.
- Packet of info that controls a characteristic.
Define chromosome. [1]
- A large group of genes. [1]
What is a stem cell and where is it produced? [2]
- An unspecialised cell that can differentiate into any type of cell [1]
- Produced from human embryos. [1]
Define differentiation.
- When a less specialised cell develops into a more specialised cell type.
What are adult stem cells and where are they produced?
- A specialised cell which can only repair specific cells.
- Produced in bone marrow.
Where does mitosis take place in plant cells?
- Takes place in the meristem found in the shoot + root tips.
Explain how treatment with stem cells can be effective. [2]
- Stem cells can be used to cure conditions [1] such as paralysis and diabetes, usually incurable. [1]
Give 3 uses for stem cells in plants. [3]
- Produces new plants clones. [1]
- Research purposes. [1]
- For agriculture. [1]
Give 3 diseases that are being researched to try and treat them. [3]
- Diabetes [1]
- Blindness [1]
- Damaged bone/cartilage [1]
Give 3 reasons why people might object against the use of stem cells. [3]
- Stem cells can be born into potential fetuses. [1]
- Waste of time and money for research and use. [1]
- The stem cell can pick up and spread a virus into the patient. [1]
