15 IMMUNITY + STEM CELLS Flashcards
What happens when stem cells differentiate
They become specialised cells
What happens to allow differentiation of stem cells to occur
Genes are ‘switched off’ so they cannot be transcribed
Describe the types of stem cells
- Embryonic - they can differentiate into any type of cell
- Adult - They can divide into a few different types of specialised cell
How can stem cells be used medically
To treat diseases, repair tissues and grow organs for transplant
Advantages and disadvantages to adult stem cell usage
- Easy to collect for treatment
- Only can become a limited number of cells
Advantages and disadvantages to embryonic stem cell usage
- Moral objection as they could’ve become humans
- They can become any type of cell
Advantages and disadvantages to embryonic stem cell usage
- Moral objection as they could’ve become humans
- They can become any type of cell
Describe the anatomy of a phagocyte
- Lysozyme within
- Lobed nucleus
Describe the process of phagocytosis
- Phagocyte recognises and engulfs pathogen
- Lysozymes containing enzymes break down pathogen
- Useful materials absorbed
- Waste products removed
What do lymphocytes need to make to attach to the pathogen’s antigen
A specific complementary antibody
Describe how a lymphocyte attacks pathogens
- Lymphocytes detect pathogen’s antigens
- Makes complementary antibody that is specific
- Releases large numbers of the antibody killing pathogens
- Memory cells are produced that make lots of antibodies very quickly if the same pathogen is detected
What is immunity
When memory cells are able to produce antibodies for a seen pathogen, killing it before we get ill
Describe how vaccination allows immunity
- The body is given a vaccine
- Either a dead pathogen or part or it’s cell
- Lymphocytes generate antibodies and make memory cells
- The second response is quicker and larger
Describe how antibiotic resistance becomes a problem
- Originally, no bacteria are resistant to the antibiotic
- A mutation gave some bacteria resistance to the antibiotic
- These bacteria become better adapted to the enviroment and they reproduce rapidly
- The resistant allele is passed on, and repreated with each generation of bacter
- The proportion of bacteria with the resistant allele increase until most have the allele
Describe how a lymphocyte attacks pathogens
- Lymphocytes detect pathogen’s antigens
- Makes complementary antibody that is specific
- Releases large numbers of the antibody killing pathogens
- Memory cells are produced that make lots of antibodies very quickly if the same pathogen is detected
