B2 - Cell Division Flashcards
What is the cell cycle?
Stage 1: Cells grow larger and replicate DNA to form two perfect copies of every chromosome. Also increase number of mitochrondia, ribosomes, etc.
Stage 2: Mitosis - chromosomes split apart, nucleus divides - cell effectively moves to two opposite sides.
Stage 3: Cytoplasm and cell membrane divides, forming two identical cells.
When do animal cells differentiate?
Early in the life cycle, when you are an embryo - however, some adult stem cells remain and replace dead or damaged cells.
When do plant cells differentiate?
Throughout their entire lifecycle.
What is the function of stem cells?
To differentiate and become specialised cells in your body during the embryonic stage, and to differentiate to replace dead cells during adult stage. It is stored in bone marrow.
How can stem cells be used by humans?
To help cure conditions like paralysis and diabetes, as the stem cells can differentiate into blood cells or nerve cells.
Stem cells from plant meristems can also be used to quickly produce clones of plants, for research, agriculture, or simply to own as decoration.
What are some possible problems with the use of stem cells?
- Some people morally question the use of humans to cure diseases - killing babies?
- It is difficult to persuade stem cells into differentiating into a specific type of cell.
- Stem cells can divide so rapidly that they turn into a cancerous tumor.
How do we stop stem cells from being rejected by a patient’s body.
By growing embryos with the same genes as a patient so that the cells are not rejected and can be easily manipulated - therapeutic cloning.
