Biology Test Definitions Flashcards
(25 cards)
Apoptosis
Regulated cell death
Regeneration
The process where a body part is replaced or regrown
Xenotransplantation
Animal to human transplants
Different types of plant cloning
Grafting and vegetative propagation
Grafting
- fruit farmers use this form of cloning to produce fruit of consistent quality
- the roots from one type of apple tree are attached to the shoots of another more desirable type of tree
Vegetative propagation
- involves taking a piece/branch from a plant and allowing it to root and produce another plant
Cloning
Cloning can be a natural or artificial process that involves forming offspring that are identical (exact same DNA)
Different types of cloning
Vegetative propagation, grafting, reproductive cloning, gene cloning and therapeutic cloning
Gene cloning
- involves the transfer of a gene into bacteria so that the gene can be reproduced many times
- used to make copies of a gene so scientists can experiment easily
- gene therapy uses this type of cloning
Therapeutic cloning
- similar to reproductive cloning but the purpose is to harvest embryonic stem cells from a developing embryo
- the harvested stem cells are used to regrow health tissue in place of damaged tissue
What is a cancer cell?
- a cell that divides uncontrollably
- occurs when there is a mutation in the cells DNA
What is a tumor
A mass of cells that continue to form and these cells don’t serve any function
What are the two different kinds of tumors
Benign and malignant
Benign tumour
when the cells stay together and do not affect surrounding tissue (not cancerous)
Malignant tumour
when the tumor interferes with the function of surrounding tissues (cancerous)
Different types of cancer treatments
- Surgery (remove cancerous tissue)
- Chemotherapy (drugs that stop the cells from dividing)
- Radiation (ionizing radiation delivered to the cancer site to damage the DNA in the dividing cancer cells)
- Immunotherapy (uses the immune system to train the body to fight against cancer cells)
Cancer screening methods
- Through imaging technologies such as endoscopes, X-rays, ultrasounds, CT scans, and MRI’s.
- Also by examining cells (taking samples and observing the size, site, and speed of growth)
How to prevent cancer
- Go for cancer screenings. It is important even if there are no symptoms.
- Early detection improves prognosis and the success rate of treatments
Reproductive cloning
- Involves the transfer of a nucleus from a donor body cell into an egg cell that has no nucleus
- The cell divides and an embryo is formed
- The embryo is transferred into the womb of a mother and begins to grow
- The mother gives birth to the clone of the donor because the embryo contains genetic information that is identical to the original body cell
What is gene therapy and how does it work
- Gene therapy involves replacing an absent or faulty gene with a normal gene
- A virus is used to carry the gene into the cell (the virus is modified so it cannot cause disease and the replacement gene is added to its DNA)
How does a cell become specialized
- All cells have the same DNA, but cells develop in different ways to perform particular functions in a process called cell specialization
- During development certain parts of the DNA “turn off” and the cell doesn’t portray those characteristics
Ethical stem cell issues
When using embryonic stem cells you must destroy an embryo which can be ethically problematic since you are destroying a potential life
Why does mitosis happen
To grow and repair
Explain why adult stem cells are difficult to use for stem cell therapies versus embryonic stem cells
- Adult stem cells are generally multi potent so they can be several cell types within a certain organ or tissue but they cannot be used for different cell types throughout the whole body
- Embryonic stem cells are pluripotent meaning they can be any cell type, anywhere in the body
