Health And Disease Flashcards
What are the physical barriers of plants?
1) A thick cellulose cell wall - provides support for the plant and protection from microorganisms.
2) A waxy cuticle - acts as a barrier to most pathogens.
3) Bark - provides a tough layer around the stem of the plant and prevents pathogens from entering.
4) Leaves closing their stomata (pores) - stops pathogens entering the plant.
What are the chemical barriers of a plant?
1) Antiseptics or antimicrobial chemicals such as proteins and enzymes.
2) Chemical poisons - deter pests that might eat them.
3) Toxins - causes aphids to fly away.
Lytic Pathway
1) The virus attaches itself to a host cell and injects its genetic material into the cell.
2) The virus uses proteins and enzymes in the host cell to replicate its DNA + produces components of new viruses.
3) The components assemble (join together).
4) The host cell bursts in a process called lysis, releasing new viruses, which infects more cells.
Lysogenic pathway
1) The virus uses restriction enzymes to insert its DNA into the host cell’s DNA.
2) The viral genetic material and host DNA gets replicated every time the host cell divides (but the virus is dormant, inactive, and no new viruses are made.
3) Eventually, a trigger (e.g. a chemical) causes the viral genetic material to leave the genome and enter the lytic pathway.
How to produce monoclonal antibodies
1) Inject animal with antigen
2) B lymphocytes produces the antibody
3) Fuses with myeloma cells, which produces a hybridoma (that divides)
4) Antibodies are isolated
Advantages of using monoclonal antibodies to treat cancer
1) The antibody attaches to cancer cell.
2) Alerts immune system to target cancer cells.
Explain how chemical defence mechanisms in the body reduce the chance of infection
1) Hydrochloric acid in the stomach destroys pathogens.
2) Lysozymes/enzymes found in tears prevents pathogens from entering.
Describe the response of the human body to immunisation
1) Immunisation causes an immune response.
2) Lymphocytes produce antibodies and memory lymphocytes.
Explain one disadvantage of treating infertility by using hormones to stimulate ovulation
More than one egg is released. This causes multiple birth/pregnancies.
Explain how monoclonal antibodies are used to test for pregnancy
1) Urine sample
2) Coloured bead attached to a monoclonal antibody
3) Antibody binds to a hormone
4) Colour indicates a positive test result
Benefits of using monoclonal antibodies to treat cancer
Monoclonal antibodies only bind to cancer cells. This reduces side effects.
Cell that produces monoclonal antibodies used to treat cancer
Hybridoma cell
Excess blood glucose is converted into glycogen in the liver
Explain how a Type 2 diabetic can regulate their blood glucose concentration
1) Exercise to reduce glucose levels.
2) Diet can be controlled to reduce glucose levels.
3) Take medication.
