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General other stuff (P2) Flashcards

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1
Q

Communicable diseases are caused by infective organisms known as?

A

Pathogens

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2
Q

Examples of bacteria that transmit communicable diseases?

A

Ring rot (potatoes) + Tuberculosis (Humans)

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3
Q

Examples of viruses that are communicable diseases?

A

HIV/AIDS and Tobacco mosaic virus

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4
Q

Types of protoctista that are communicable diseases?

A

Malaria and tomato/potato blight

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5
Q

Types of fungi that are communicable diseases?

A

Black stigatoka (bananas) and athletes foot

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6
Q

Ring rot (type of disease and what it does) -

A

A bacterial disease

Damaged leaves, tubers and fruit damaging most of the crop

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7
Q

Tobacco mosaic virus (Pathogen type and what it does to plant) -

A

A virus

Affects tobacco plants, damages leaves, flowers and fruit and reduces yield

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8
Q

Black sigatoka (Pathogen and what it does to plant) -

A

Fungal infection

Attacks the leaves destroying it, turns the leaves black (fungicide can control it)

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9
Q

Tuberculosis (Pathogen and what it does to the animal) -

A

Bacterium

Damages and the destroys the lung tissue suppresses the immune system weakening it against other diseases.

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10
Q

Potato blight (tomato blight) (Pathogen and what it does to plant) -

A

A fungal infection

Destroys leaves, tubers and fruit, causing loss of crop yield.

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11
Q

HIV/AID’s (Type of pathogen and what it does to humans) -

A

Virus

Targets T-helper cells in the immune system, so people are more open to other infections.

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12
Q

Influenza (Pathogen type and what it does to animals) -

A

Virus

Kills the ciliated epithelial cells, opening the airways to secondary infection.

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13
Q

Malaria (Pathogen and what it does to humans) -

A

Protoctista

Spread by mosquitos, invades the red blood cells and plasmodium is passed on to people.

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14
Q

Athletes foot (Type of pathogen and what it does) -

A

Fungus

Grows and digests on warm moist skin between the toes, is itchy.

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15
Q

Types of direct transmission (Where the pathogen is directly transferred from one organism to another) - animals

A

Direct contact - (Kissing or any contact with the others bodily fluid and sexual transmitted diseases)

Inoculation - Through a break in the skin, or an animal bite (rabies) or puncture in wound.

Ingestion - Taking in contaminated foods or drink

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16
Q

Types of indirect transmission (Passing of pathogens between organisms indirectly) - animals

A

Droplets infection - saliva and mucus are expelled when talking, if breathed in with the pathogen they may become infected.

Vectors - Transmits communicable diseases from host to another, like mosquitos transferring malaria also water (cholera)

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17
Q

Indirect transmission between plants for types of pathogens -

A

Soil contamination - Infected plants leave pathogens in the soil, like black sigatoka pores.

Wind - spores may be transmitted via the air

Animals - Insects and birds carrying pathogens and spores

Humans - transmitted by contaminated hands

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18
Q

Plants have physical defences protecting from the risk of infection -

A

They produce high levels of the a polysaccharide called callose which is believed to sit between cell walls of the infected plant acting as barriers preventing the pathogen entering the plants from the outside, also deposited in the plasmodesmata between infected cells between neighbouring cells sealing them off from healthy cells

Also contain a large waxy cuticle which shut of pathogens of entry.

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19
Q

Chemical defences in plants -

A

Chemicals called saponins which destroy cell membranes and fungi and other pathogens,

Phytoalexins inhibit the growth of pathogens

Other chemicals are toxic to insect which stop insects passing of infections they carry as vectors.

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20
Q

Non-specific defences stop pathogens entering animals these apply to how many pathogens -

A

All pathogens but not always the most effective.

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21
Q

Types of non -specific defences of keeping pathogens out - (skin)

A

Skin - Physical barrier from pathogens has skin flora of healthy microorganisms which outcompete pathogens and contains sebum which is oily inhibiting growth.

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22
Q

Types of non -specific defences of keeping pathogens out - (Blood clotting) -

A

Platelets come into contact with collagen in skin of the wall which is breached (cut) which secrete substances:

  • Thromboplastin - enzyme triggering a cascade of reactions and the result of blood clot (Fibrinogen catalyses to fibrin to clot)

Serotonin - contracting of blood vessels stopping blood flow to that area.

The clot dries forming a tough, hard scab keeping pathogens out

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23
Q

Types of non -specific defences of keeping pathogens out - (Inflammatory response)

A

Localised response to pathogens, response is inflammation at site of wound, characterised by pain, heat, swelling and redness of tissue.

Mast cells are activated in damaged tissue and release chemicals of histamines and cytokines

H - Blood vessels dilate, raised temperature stop pathogens reproducing + makes blood vessels more leaky so tissue fluid is formed from hydrostatic pressure which causes swelling and pain.

C - attract white blood cells to site and dispose of them by phagocytosis.

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24
Q

Expulsive reflexes in the non-specific defences -

A

Coughs and sneezes eject pathogens from the mucus of the gas exchange system, vomiting and diarrhoea the contents of the gut.

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25
Mucous membrane in the non-specific defences -
Secrete sticky mucous which traps microorganisms and contains lysosomes which destroy bacterial and fungi cell walls. Also contain phagocytes.
26
Non - specific defences of getting rid of pathogens are when?
The pathogens are in the body and are used to prevent growth
27
Fever in the prevention of pathogens multiplying (Non - specific defence of getting rid of pathogens) -
Pathogens invading the body result in the raised temperature which is regulated by the hypothalamus and is stimulated by cytokines, the adaptation of the rising temperature make the specific immune system to work more efficiently and inhibiting the growth of invading pathogens are higher temperatures.
28
Phagocytosis of Non-specific defences of getting rid of pathogens (what are they and examples) -
- Specialised WBC - Digest and engulf pathogens - Macrophages and neutrophils
29
Stages of phagocytosis - 1 Chemicals produced by pathogens
This attract phagocytes to the site of infection
30
Stages of phagocytosis - 2 Phagocyte recognises a foreign cells -
Non - human proteins on the pathogen are recognised, response to a non-self organism
31
Stages of phagocytosis - 3 Engulfing the pathogen -
Engulfs the pathogen and encloses in the vacuole called a phagosome
32
Stages of phagocytosis - lysosome comes in
Phagosome combined with the lysosome to form a phagolysosome where enzymes from the lysosome digest and destroy the pathogen.
33
Why does a macrophage take longer to digest a pathogen?
When digested it combines antigens from the pathogen surface membrane and glycoproteins in the cytoplasm (MHC) major histocompatibility complex. The MHC complex moves the pathogen antigens to the macrophages own surface membrane becoming an antigen presenting cells, these antigens stimulate other cells involved in the specific immune system.
34
Counting blood cells of how many are used in preventing infection -
Often stained to show the multi-lobed nuclei of the lymphocytes, indicating the number of different types of lymphocytes determines if it non-specific or specific immune system is happening.
35
Cytokines are produced when a phagosome has been digested what do they do -
Act as cell-signalling molecules informing the other phagocytes the body is under attack and allow them to move to the site of infection, increase body temperature and trigger the specific immune system. Produced from the wound
36
Role of opsonin's in pathogens -
Chemicals which bind to the pathogens and tag them so they are easily recognised by phagocytes. These can act as binding sites for phagocytes on the cell membrane to bind phagocytes.
37
How does the body recognises non-self antigens?
All cells have antigens the body recognises between self antigens on our own cells and non-self antigens on pathogens
38
Antibodies - what they are?
Antibodies are Y-shaped glycoproteins called immunoglobulins and bind to specific antigen binding sites on the pathogen or toxin. Bind with based lock and key on the binding site known as the variable region, the rest of the body is the constant region which is used by all antibodies but the binding site is different. When antibodies bind to the antigen it makes an antigen-antibody complex
39
Antibodies/Immunoglobulins structure -
- Made up of 2 long polypeptide chains called the heavy - Contain 2 much shorter chains called the light chains Held by disulphide bridges within the polypeptide chains holding them in place.
40
Role of antibodies defending the body - opsonin in the antibody
When the antigen-antibody complex they act as opsonin, so its easily engulfed by phagocytes and tag the pathogens
41
Antigens as agglutinins -
Cause antigen-antibody complexes to clump together and stop them spreading in the body and makes it easier for phagocytes to engulf.
42
Antibodies as anti-toxins -
Bind to toxins produced by pathogens and make them harmless.
43
The immune system is based on lymphocytes where are they produced? (B and T) -
B in bone marrow T in thymus gland
44
T helper cells -
Produce interleukins, which are a type of cytokine used in cell signalling, increase the release of B cells, which increase antibody production and stimulate macrophages to ingest pathogens antigen-antibody complexes.
45
T killer cells -
Destroy the pathogen carrying the antigen, produce chemical called perforin, makes holes in the cell membrane so its freely permeable.
46
T memory cells -
Part of the immunological memory, if they meet an antigen a second time, they divide rapidly to release a large amount of T killer cells.
47
T regulator cells -
Suppress the immune system, stop the immune system once the pathogen is eliminated. Stops the immune system from attacking the hosts body cells.
48
Plasma cells (B lymphocyte) -
Produce antibodies to a particular antigen and release in circulation
49
B effector cells -
Divide into plasma cell clones
50
B memory cells -
Live for a long time and provide immunological memory, they remember a specific antigen and when a pathogen carrying the antigen is met again it can make a rapid response.
51
Cell mediated immunity -
Non-specific defence system, macrophages engulf and digest pathogens, the process the antigens from the surface of the antigen to form antigen-presenting cells. T helper cells become activated if they fit they antigens and produce interleukins, stimulating mitosis and clones of T helper cells/
52
What may cloned T helper cells do in cell-mediated immunity -
The cloned T cells may help with: - Becoming T memory cells which give a rapid response if pathogens invade again - Produce interleukins stimulating phagocytosis and B cells to divide
53
Humoral immunity respond to cells which are where?
Outside the cells they are soluble in the blood and tissue fluid.
54
Humoral immunity (clonal selection and expansion) -
T helper cells that are activated bind to the B cell, this clonal selection where the B cell with the correct antibody to overcome the antigen is cloned. B cells that are activated by interleukins divdide by mitosis to give clones of plasma and B memory cells, this is clonal expansion. Where the cloned antibodies fit the antigens on the pathogen surface disabling them Primary response Secondary responses result from cloned B memory lymphocytes divide rapidly to form cell clones producing the right antibody to wipe the pathogen very quickly.
55
Autoimmune disease -
Stops recognising self cells and starts to attack healthy body tissue. They believe they are foreign cells. Arthritis, muscle spasms.
56
Natural active immunity -
Active where the body acts itself to make the antibodies/memory cells, your own immune system makes these cells.
57
Natural passive immunity -
Cannot make their own antibodies, some antibodies pass across the placenta naturally, occurs in breastmilk of the mother too when they contain colostrum which is high in antibodies.
58
Artificial passive immunity -
Where antibodies are formed in another organism and extracted and injected into another bloodstream, not life sustaining but can be life saving. E.G tetanus causes muscles to go into spasm by a toxin and released by bacteria cannot swallow or breathe. Can be injected with tetanus antibodies extracted from horses.
59
Artificial active immunity -
The body is stimulated to make its own antibodies which they couldn't make initially into a safe form of an antigen (vaccine). The pathogen is made safe and no risk of infection.
60
Herd immunity -
Significant number of the population have been vaccinated this gives protection to those who haven't been vaccinated.
61
Some diseases cannot be vaccinated against -
Malaria - the plasmodium spends time in the erythrocytes so it is protected by self antigens from the immune system. HIV - enters the macrophages and T helper cells so it has disables the immune system itself.
62
Sources of medicines - Penicillin
Penicillin cures bacterial diseases and was first discovered on watermelons effective against bacteria.
63
Sources of medicines - Docetaxal
Derived from yew trees and treatment for breast cancer.
64
Why it is important to maintain biodiversity and microorganisms -
With biodiversity decreasing and habitats of coral reefs, forests. Important to not destroy, plants or microorganisms that contain the potential for a life-saving drug.
65
Synthetic biology -
Genetic engineering of bacteria to produce much needed drugs that would be too expensive and rare to produce.
66
Antibiotic resistant bacteria -
Bacteria produce very rapidly so one mutation that occurs does not take long to grow to a population. become a particular problem in hospitals and care homes. Can be reduced by good hygiene and minimising the use of antibiotics and ensuring every course of antibiotics is completed to reduce the risk.
67
The problem of antibiotic resistance -
Genetic variation and mutations which lead bacteria resistant to to antibiotics, making bacteria more likely to survive and allow later offspring more likely to survive.
68
MRSA (antibiotic resistant bacteria) -
Causes serious wound infections and is resistant to many several antibiotics
69
Continuous variation -
When the individuals in a population can vary within a range (Body mass)
70
Discontinuous variation -
2 or more distinct categories where each of the individual falls into one of these categories.
71
Genotype -
Alleles of an organism, their genetic make-up
72
Phenotype -
The observable characteristics of an organism.
73
Homozygous -
Two identical alleles for a characteristic can be dominant (HH) or recessive (hh)
74
Heterozygous -
Two different alleles for a characteristic, the dominant allele will always be expressed.
75
Co-dominance -
When two alleles occurring for the same gene are both dominant.
76
Multiple alleles -
Genes which have more than 2 versions
77
Sex linkage -
Characteristics are determined by genes on sex chromosomes, cause phenotypic ratios to vary
78
Autosomal linkage -
Autosomes are non-sex chromosomes, the closer the genes are on the autosome the more closely linked they are suggested to be. Cause phenotypic ratios to vary
79
Epistasis -
Interactions of genes at different loci results in genes interacting together where these genes can control the same characteristic, so one gene can block the expression of another. Shouldn't expect the ratio 9:3:3:1 because the genes are not interacted.
80
Factors affecting evolution -
Natural selection - individual has characteristics that are favourable to their environment and so reproduction will increase Genetic drift - Occurs in small populations, due to the changes in allele frequency due to random mutation Gene flow - movement of alleles between population migration of some organisms.
81
Founder effect in evolution -
Small populations can arise due to the formation of small colonies, smaller gene pool and less genetic variation
82
Stabilising selection -
Results in reduction frequency of alleles in extremes who are less advantageous in their environment like smaller babies who are more prone to infection.
83
Directional selection -
Occurs when there is a change in the environment and the phenotype is no longer the most advantageous, where the allele frequency shifts to the extreme phenotypes.
84
Speciation -
Formation of a new species through the process of evolution. (Allopatric and sympatric)
85
Allopatric speciation -
Most common happens when some members of the population are separated by a physical barrier and become geographically isolated and be open to selection pressures, often lead to founder effect and the lead of genetic drift.
86
Sympatric speciation -
Occurs within populations which share the same habitats, more common in plants than animals, where two different species interbreed and a new hybrid forms which cannot pass on offspring itself due to the number of chromosomes and it cannot interbreed.
87
Problems with artificial selection
Reduces gene pool and Recessive alleles result in many genetic disorders Less genetic diversity
88
Hardy Weinberg principle -
Predict the idea that allele frequency wont change from one generation to the next P = Dominant alleles Q = Recessive alleles
89
PCR -
1. Heat up the DNA breaks by the hydrogen bonds at 95 degrees 2. primers at 55 degrees, bind to the DNA, stops the strands to move back together and allow DNA polymerase to make phosphodiester. 3. 72 degrees to new fragments are made from the use of DNA.
90
Plant cells can be artificially cloned from existing plants -
Cells can be be taken from the stems and root tips and can differentiate into any type of cell, sterilised to kill any microorganisms. Placed in culture medium which contain all useful products for growth (glucose and hormones)
91
Animals can be produced artifically by
Artificial embryo twinning and SCNT (Somatic cell nuclear transfer) -
92
Artificial embryo twinning -
Egg cell is extracted and fertilised in petri dish left to divide at least once in vitro The individual cells from the embryo are placed in petri dishes, before being implanted in surrogate mothers The embryos develop until eventually the offspring is born.
93
Somatic cell nuclear transfer -
Somatic cells (not a reproductive cell) is taken from a sheep. Immature egg cell is taken from another sheep its nucleus is removed, the nucleus from sheep A is taken and put in the oocyte in Sheep B where their nucleus is removed before hand, so it becomes fused with the nucleus and endonuclease oocyte (electrofusion) produces an embryo The embryo is placed in a surrogate mother and a lamb is born.
94
Biotechnology -
Industrial use of living organisms , mainly microorganisms, they grow rapidly under their short life cycles if pH, temperature and nutrients are suitable. Use parts of living organisms like enzymes, specifically intracellular enzymes
95
Pros of using microorganisms for food -
Cheap, can be grown, quickly and efficiently with the right equipment, use single-cell protein which can be made by many different organic substrates.
96
Cons of using microorganisms for food -
Single cell protein doesnt have the same flavour as animals, some people may not like of eating food made by waste products and due to the idea of meeting favourable conditions there is a great sense that other bacteria may grow in these conditions which is unwanted.
97
Phylogeny -
The evolutionary relationships between organisms.
98
Evidence for evolution -
Palaeontology - study of fossils Comparative anatomy - difference and similarities in anatomy Comparative of biochemistry - similarities and differences between the chemical makeup of organisms.
99
Genetic variation -
Alleles, mutations and meiosis
100
Types of adaptations -
Anatomical - physical features Behavioural - way the organisms act Physiological - process that take place inside the body.

Biology (19 decks)

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