bio - communicable & non communicable diseases

Question 1

Pathogen

Answer 1

microorganisms that cause infectious diseases
relies on their host to provide the conditions they need to grow and reproduce

Question 2

Bacteria

Answer 2

Not all bacteria is bad
some are pathogens & cause diseases
Can be spread by: ingesting contaminated food, preparing food in unhygienic conditions, sexual contact
Antibiotics are becoming useless against bacteria as bacteria learns how to beat them by sharing their plasmids

Question 3

Viruses

Answer 3

Very small pathogens - not living cells
has a strand of genetic material inside a protein coat - this replicates inside host cells to make new viruses

Question 4

Plant defence responses

Answer 4

Physical - barriers e.g., Tough waxy cuticle around upper leaf, layer of dead cells around stem, cell wall
Mechanical thorns & hairs – prevents insects
Chemical - use of chemicals to attract or repel certain animals/organisms

Question 5

Protists

Answer 5

Single celled eukaryotic microorganisms

Question 6

Smoking

Answer 6

Chemical Carcinogens in cigarettes increase the chance of lung cancer.
Damages lining of arteries leading to atheroma build-up and a heart attack + stroke.
COPD - Chronic Obstructor Pulmonary Disease as smoking destroys many alveoli, so airways become inflamed & mucus builds up → patient become breathless.

Question 7

Alcohol

Answer 7

Damages liver
yellow eyes
drowsiness
vomiting blood
alcoholic hepatitis
cirrhosis of the liver
alcoholism increases. treatment costs from the NHS

Question 8

Diet

Answer 8

Bad diet leads to type 2 diabetes
Balanced diet + lack of highly processed foods → less chance of cardiovascular diseases or type 2 diabetes
Obesity leads to high blood pressure & build deposits up of fatty deposits leading to cardiovascular disease

Question 9

Smoking (leads to)

Answer 9

Lung disease, cancer
Low birth weight & premature birth

Question 10

Alcohol (leads to)

Answer 10

Liver & brain damage
Abnormal foetal brain development

Question 11

Obesity (leads to)

Answer 11

Type 2 diabetes

Question 12

Poor diet, smoking & no exercise (leads to)

Answer 12

Cardiovascular disease

Question 13

Carcinogens & radiation (leads to)

Answer 13

Cancer

Question 14

Health

Answer 14

state of physical and mental well-being

Question 15

Measles

Answer 15

Type - Virus
cause - Droplet infection
Symptoms - Itching, fever
Cure - Vaccination

Question 16

HIV

Answer 16

Type - Virus
cause - direct contact bodily fluids
Symptoms - AIDS, weak immune system
Cure - antiretroviral drugs prevent virus from replicating

Question 17

Salmonella

Answer 17

Type - Bacteria
cause - food and contaminated utensils
Symptoms - stomach aches, vomiting, diarrhoea
Cure -Vaccinating animals / hygienic food prep

Question 18

Gorrhoea

Answer 18

Type - Bacteria
cause - unprotected sex
Symptoms - pain in urinating, discharge from genitals
Cure - Barrier contraception, antibiotics

Question 19

Tobacco mosaic Virus (TMV)

Answer 19

Type - Virus
cause - Get through wounds in the plant
Symptoms -Reduced photosynthesis, discoloured leaves, stunted growth
Cure - removing infected part of plant

Question 20

Aphid infection

Answer 20

Type - Virus
cause - aphids greenflies are vectors
Symptoms - Stunted growth, yellow leaves
Cure - Insecticides & Natural predators of vector e.g. ladybird

Question 21

Rose Blackspot

Answer 21

Type - fungus
cause - Spores
Symptoms - black slash purple spots on upper surface of leaves
Cure - Burning infected areas in an enclosed chamber

Question 22

Malaria

Answer 22

Type - protists
cause - mosquitoes are vectors for malaria
Symptoms - Recurrent fever, cough, muscle pains, headaches, sweats and chills
Cure - Vaccination, Mosquito Nets and repellent

Question 23

read me

Answer 23

The Immune System is designed to protect us from viruses and bacteria but can also respond to Allergens such as pollen or dust.
The body usually identifies allergens as harmful as soon as they enter the sinuses. The immune system responds by producing antibodies to fight off the allergen. Although the immune system produces antibodies in relatively small quantities the first time it encounters an allergen, subsequent exposures result in a specific immune response.
With repeated exposure, the body produces large amounts of the antibody greater to that allergen and stimulates mast cells in the respiratory system to release histamine, a chemical responsible for traditional allergic symptoms such as a runny nose, coughing, itchy eyes, and sneezing. This same chemical is responsible for other allergic reactions in the skin that result in itches and some inflammation.
By releasing histamine and manufacturing allergic Symptoms the body has created a process to expel the allergen out of the body. Runny noses, coughing, and sneezing all help rid the body of the presumably harmful allergen.

Question 24

Cancer

Answer 24

when abnormal cells divide in an uncontrolled way

Question 25

Benign tumour

Answer 25

Stays and grows in one place

Question 26

malignant tumour

Answer 26

grows into other tissues and metastasize

Question 27

how cancer happens

Answer 27

Question 28

How is malaria transmitted

Answer 28

Question 29

lifecycle of mosquitos

Answer 29

Question 30

methods of controlling mosquito (malaria’s vector) lifecycle

Answer 30

1) Draining stagnant pools of water - gives the raft of eggs / larva / pupa no stagnant water to live in so they die
2) Spraying pools of water with insecticides - It chemically kills the raft of eggs / larva / pupa
3) Spraying pools of water with oil - prevents pupa from breathing air & reduces O2 content of water so Larva & raft of eggs die

Question 31

First line of defence against pathogens in humans

Answer 31

• mucus in mouth, nose, and trachea traps pathogens
• trachea and bronchus are lined with cilia, which “waft” mucus back up to the throat to be swallowed
• urine is antimicrobial and kills pathogens.
• scabs form a protective barrier to stop bacteria entering.
• tears are antimicrobial.
• hairs in nose to trap larger particles.
• skin is a tough barrier, with a dead outer layer of cells that microorganisms can’t penetrate, glands secrete antimicrobial oils.
• stomach is full of hydrochloric acid which kills microorganisms.
• Ear wax, eye lashes

Question 32

Second line of defence against pathogens in humans

Answer 32

The second line of defence is also non-specific. It involves a type of white blood cell called phagocytes. They are attracted to any area of your body in which an infection is present. Then, they engulf the pathogen through phagocytosis.

Question 33

Phagocytosis

Answer 33

Phagocytes engulf pathogens by phagocytosis. by then the pathogen is engulfed and enclosed in a vacuum and digestive enzymes are secreted. the enzyme kills and digests the pathogen.

Question 34

antigen

Answer 34

a specific shaped protein on the surface of each pathogen. They are specific to the pathogen.

Question 35

Lymphocytes - antibodies

Answer 35

Lymphocytes are white blood cells. Lymphocytes recognise only one type of antigen and binds to it once it comes into close proximity. They can also produce antibodies specific in shape to the antigens of that pathogen. It takes multiple days to find the correct shape, in which time illness is felt. So, they release the antibodies into the blood. These antibodies are going to bind to the antigens of that pathogen causing the pathogens to clump together making it more vulnerable to phagocytosis & the antibodies will kill the pathogens.

Question 36

Memory Lymphocytes

Answer 36

After the infection and the pathogens have died, the memory lymphocytes and antibodies remain in the blood. What happens if you’ve got a secondary infection of the same, pathogen, your memory lymphocytes will very quickly produce correct antibodies which will bind to the pathogens, as no time needs to be wasted finding the correct lymphocyte.

Question 37

Lymphocytes - antitoxins

Answer 37

Lymphocytes also make antitoxins which bind to any toxins the pathogen makes, neutralising it. Toxins are what make you feel sick.

Question 38

specific antibodies shape

Answer 38

Just like enzymes the antibody binds to specific antigens because the shape of the antigen is complementary to the shape of the antigen binding site.

Question 39

How does a vaccination work?

Answer 39

A vaccine is a small quantity of a dead or inactive pathogen. it still possesses the same antigens as a normal pathogen so that the body develops memory lymphocyte cells that’s recognise the active pathogen too.

Question 40

immune response to disease exposure

Answer 40

1) Afterthe initial exposure, lots of different lymphocytes attempt to make antibodies complimentary to antigens on the pathogen.
2) once an antibody binds correctly, the lymphocyte differentiates to make plasma cells and memory cells.
3) The plasma cells produce antibodies and help the phagocytes fight off the infection.
4) once the pathogen is defeated, the plasma cells die but the memory cells remain.
5) Reinfection is instantly recognised by memory cells which quickly produce lots of plasma cells.

Question 41

how are monoclonal antibodies made

Answer 41

1) Inject mouse with chosen antigen that you want to produce antibodies for

2) The mouse’s lymphocytes are now going to produce specific antibodies for that antigen.

3) Remove the lymphocytes from the mouse. This lymphocyte produces the antibodies that you want to make the monoclonal antibodies from. So even though this lymphocyte can produce antibodies, it can’t divide.

4) Fuse the lymphocyte with a cancer cell (a tumour cell). The tumour cell can’t produce antibodies, but it can divide incredibly rapidly by mitosis. This forms a hybridoma which can divide incredibly rapidly and produce many monoclonal antibodies, which are all specific to the same antigen.
5) Hybridoma is cloned and many identical hybridoma’s are produced
6) All hybridomas make multiple antibodies which are collected and purified producing monoclonal antibodies.

Question 42

3 uses of monoclonal antibodies

Answer 42

Diagnosis – eg pregnancy tests/ covid tests
Research - to locate or identify specific molecules in cells
Treatment – eg cancer treatment, binding to cells and carrying a radioactive or toxic substance

Question 43

role of monoclonal antibodies in cancer treatment

Answer 43

chemotherapy drugs kill all cells, but particularly fast-growing cells like cancer cells. This unfortunately includes other cells like hair, skin and intestinal cells resulting in hair loss, cracked skin and digestive problems. However, mAbs targets cancer cells while leaving healthy cells unaffected and they also target the toxic drugs to specific places in the body reducing the number of accidental cell deaths.
e.g. herceptin stops breast cancer cell growth

Question 44

role of monoclonal antibodies in treating a disease

Answer 44

Treating diseases
Different cells in the body have different antigens on their cell surface. So you can make monoclonal antibodies that will bind to specific cells in the body (e.g. just liver cells). Cancer cells have antigens on their cell membranes that aren’t found on normal body cells. They’re called tumour markers. In the lab, you can make monoclonal antibodies that will bind to these tumour markers.
An anti-cancer drug can be attached to these monoclonal antibodies. This might be a radioactive substance, a toxic drug or a chemical which stops cancer cells growing and dividing. The antibodies are given to the patient through a drip. The antibodies target specific cells (the cancer cells) because they only bind to the tumour markers. The drug kills the cancer cells but doesn’t kill any normal body cells near the tumour.

Question 45

phases of drug research

Answer 45

Preclinical - Tested on cells then on engineered mice. Does it work? how much? side effects?
Clinical - phase one - tested on a small no. of healthy male volunteers – safety?
Clinical - phase two - tested on a small number of patients - Does it work? how much?
Clinical - phase three - large scale trials - does it work for all? getting the dose right.
Clinical - phase four - distribution and scalability - despite drug being available it is still monitored and checked for long term effects

Question 46

Single blind trial

Answer 46

patients don’t know who’s getting the placebo but doctors do.

Question 47

double-blind trial

Answer 47

neither patients nor doctors know you who is getting the placebo and who isn’t. only drug company knows.

Question 48

use of monoclonal antibodies in research

Answer 48

Using monoclonal antibodies in research
Monoclonal antibodies can be used to locate specific molecules on a cell or in a tissue. First, monoclonal antibodies are made that will bind to the specific molecules you’re looking for. The antibodies are then bound to a fluorescent dye. If the molecules are present in the sample you’re analysing, the monoclonal antibodies will attach to them, and they can be detected using the dye.

Question 49

problems with monoclonal antibodies

Answer 49

However, monoclonal antibodies do cause more side effects than were originally expected, e.g. they can cause fever, vomiting and low blood pressure. When they were first developed, scientists thought that because they targeted a very specific cell or molecule, they wouldn’t create a lot of side effects, but in some cases the unpleasant side effects outweigh the benefits of the treatment. This means that they are not as widely used as treatments as scientists had originally thought they might be.

Question 50

Monoclonal antibodies - pregnancy test strip

Answer 50

Pregnancy tests rely on monoclonal antibodies which bind to ahormone(HCG) which is made in the early stages of pregnancy.

The reaction zone contains mobile monoclonal antibodies specific to HCG with a blue dye attached to them

The results zone contains immobilised monoclonal antibodies specific to HCG

The control zone contains immobilised antibodies that bind to antibodies attached to blue dye

Question 51

Monoclonal antibodies - pregnancy test strip - posititve result

Answer 51

If a woman is pregnant, her urine will contain HCG.

When urine touches the reaction zone, HCG will bind to the monoclonal antibodies

As the antibodies are ‘free’, they will be carried up the test with the urine

The immobilised monoclonal antibodies in the results zone will bind to the HCG; and hold some of the dye within the zone. This will create a blue line on the test

Other dye that has not bound in the results zone will move into the control zone. Here, immobilised antibodies from the control zone will bind to antibodies attached to the dye. This will create a second blue line

Question 52

Monoclonal antibodies - pregnancy test strip - negative result

Answer 52

If a woman is NOT pregnant, her urine will NOT contain HCG.

When urine touches the reaction zone, no HCG will bind to the monoclonal antibodies

As the antibodies are ‘free’, they will be carried up the test with the urine

The antibodies attached to the blue dye will not bind in the results zone as there is not HCG present to bind to the immobilised antibodies.

However, the antibodies attached to the dye will still bind to the immobilised antibodies in the control zone. This creates a single blue line