Immunity

Question 1

Mechanical barriers

Answer 1

Thick waxy cuticles and thick bark in plants. Skin and mucous membranes lining digestive and respiratory animal tract

eg sneezing, coughing, tear production

Question 2

Chemical barriers

Answer 2

Toxins and tannins produces in leaves of plant to stop them from being eaten. Secretion of sebum containing antibacterial chemicals from sebaceous skin glands

eg acidic stomach acid pH

Question 3

Mutualistic bacteria present

Answer 3

Non-pathogenic bacteria inhabit intestine and vagina, preventing parasitic bacteria from staying

Question 4

Inflammatory response

Answer 4

Pathogenic bacteria get through first and second lines of defence, leading macrophages to engulf bacteria.

Question 5

Acquired immunity

Answer 5

Once body has created antibodies in response to specific antigen, memory cells store information.

Can be acquired passively (eg from mother to child through placenta or breast milk)

Actively acquired through exposure to pathogens or vaccination - therefore causing body’s immune system to create antibodies

Question 6

Antibodies

Answer 6

Specific proteins produced on the cell membrane of lymphocytes. Different microbes have different antigens attached to the cell membrane - antibodies attaching to microbe causes the microbe to become inactive.

Question 7

B - lymphocytes

Answer 7

Receptor proteins on the surface that attach to specific antigens.

Receptor proteins recognize proteins as foreign

B lymphocytes multiply

New B-lymphocytes produce antibodies - these mark pathogens for phagocytes and cause agglutination

Question 8

T - lymphocytes

Answer 8

Recognize and destroy the body’s cells that are infected

Viruses that cannot be reached by antibodies

T-lymphocytes recognise and destroy virus infected membranes by secreting chemicals which cause cell to burst

CD4 Cells = T Lymphocytes initiating immune response

Question 9

Live vaccines

Answer 9

Contain living micro-organisms which are modified to prevent causing the original disease

Microbes immediately start reproducing = more antibodies created (can cause mild reaction)

Need to be refrigerated as there is slight chance microbes mutate

Question 10

Killed vaccines

Answer 10

Contain solutions of dead microbes that can still cause an immune response

Less effective than live vaccines, usually require you to get 2-3 injections and then booster shots

No living microbes = immune response is less = course of vaccination needed

Question 11

Bacterial antibiotics

Answer 11

Directly kill bacteria such as pencillin and cephalosporins. They interfere with the chemicals bacteria use to form cell walls

Question 12

Bacteriostatic antibiotics

Answer 12

Halts the multiplication of bacteria and enables the body’s natural defenses.

Alters the chemical activity inside the actual bacteria, preventing the production proteins the bacteria need in order to multiply and survive

Question 13

Antibiotic resistance

Answer 13

Increasing use of antibiotics has led to resistance.

DNA of microorganisms mutates during reproduction, creating growth mechanism that are not disrupted by antibiotics

Question 14

Cause of antibiotic resistance

Answer 14

Caused by prolonged tratment or medicine not taken properly

Resistant bacteria multiplies, prolonging the illness and may infect other people which spreads the resistant bacteria

Doctors try and prevent this by choosing the antibiotic most likely to eliminate bacteria and being more cautious with prescriptions