Module 4 – Biodiversity, evolution and disease Flashcards

Question

C10) How has comparative anatomy of homologous structures helped prove evolutionary theory

Answer 1

Homologous structures are structures that appear or function significantly different in different organisms but has the same underlying structure For example the bone structure of the limbs in the flying vertebra are similar to a walking vertebra or a swimming vertebra but their functions have changed this could be due to being evolved from a common ancestor Homologous structures provide evidence of divergent Evolution this Describes how different species with a different set of adapted features have evolved from a common ancestor

Answer 2

Is the study of similarities and differences in the proteins and other chemicals that control life processes. For example cytochrome C (involved in respiration) and ribosomal RNA To discover how closely related to species are the molecular sequence is compared by looking at the DNA bases or the order of amino acids. The number of differences that exist are plotted against the rate the molecule undergoes natural base pairs substitution. From this they can estimate the point where the two species shared a common ancestor. Species who are closely related have similar DNA and proteins whilst distantly related have fewer similarities

Answer 3

And organisms genetic material – difference in the genetic material of an organism inherited from its parents lead to genetic variation The environment in which the organism lives - causes environmental variation

Answer 4

Interspecific variation-between members of different species Intraspecific variation – between organisms within a species

Answer 5

Alleles - Different alleles produce different effects. Individuals in a species population may inherit different alleles of a gene Meiosis - gametes are produced by meiosis in organisms that break produce sexually. Each gamete receives half the genetic information of a parent cell. Genetic material inherited from the two parents is mixed up by independent Saltman and crossover. Leading to gametes of an individual showing variation Chance - many different gametes are produced from the parental genome. During sexual reproduction it is the result of chance as to which two combinations-random fertilisation. Individuals produce therefore differ from siblings as each contain a unique combination of genetic material

Answer 6

Asexual reproduction results in the production of clones – individuals that are genetically identical to parents Genetic variation can only be increased and these organisms as a result of mutation

Answer 7

All organisms are affected by the environment in which they live, although plants may be affected to a greater degree than animals due to the lack of mobility

Answer 8

With the use of twins who are split up at birth and sent to different environments

Answer 9

most cases of variation are caused by a combination of both environmental and genetic factors For instance the height of a person can be genetic as it can be influenced by your parents height but also environmental as a good diet is needed to grow above average height

Answer 10

Characteristic that can only result in certain values No in between value Variation determined purely by genetic factors Falls into this category. Normally represented using a bar chart Controlled by a single gene

Answer 11

Characteristic that can take any value within a range not controlled by a single gene but a number of genes Also often influenced by environmental factors Continuous variation data is collected in a frequency table and plotted on a histogram then a curve is drawn onto the graph to show the trend

Answer 12

When continuous variation data is plotted onto a graph usually result in the production of a bell shaped curve known as the normal distribution curve

Answer 13

The mean, mode and median are the same The distribution has a characteristic bell shape, which is symmetrical about the mean 50% of values are less than the mean and 50% or greater than the mean Most values like close to the mean value - number of individuals are at the extremes are low

Answer 14

Is a measure of how spread out the data is The greater the standard deviation the greater the spread of the data A characteristic which has a high standard deviation has a large amount of variation

Answer 15

68% of values are within one standard deviation of the main 95% of values are within two standard deviations of the main 99.7% of values are within three standard deviations from the mean

Answer 16

Used to compare the means of data values of two populations

Answer 17

Used to consider the relationship between two sets of data

Answer 18

(n1-n2)-2 Where n1 = population one, n2 = population 2

Answer 19

Characteristics that increase in organisms chance of survival and reproduction in its environment Many adaptations fall into more than one category

Answer 20

Anatomical adaptations- physical features, internal and external Behavioural adaptations- the way an organism acts. This can be innate (instinctive) through genes or learnt from their parents Psychological adaptations- processes that take place inside an organism

Answer 21

Body covering- animals have a number of different body coverings are such as hair, scales, spines, feathers and shells. Can help: organisms to fly such as feathers on birds, help to stay warm such as polar bears, provides protection such as snail shells. Thick waxy layer on plants prevent water loss and spikes can deter herbivores and protect the tissue from some damage Camouflage- the outer colour of an animal allows it to blend into its environment making it harder for predators to spot it. Teeth- The shape and type of teeth present in an animal jaw are related to its diet. herbivoresSuch as sheep have continuously growing molars for chewing Tough grass and plants. Carnivores have sharp long canines to kill pray and tear meet Mimicry- copying other animals appearance or sound allows an harmless organism to fool predators into thinking it is poisonous or dangerous

Answer 22

It’s a Xerophyte, A plant that has adapted to live in an environment with a little water Curled leaves to minimise the surface area of moist tissue exposed to the air and protect the leaves from the wind Hairs on the inside surface of the leaves to trap moist air close to the leaf reducing the diffusion gradient Stomata sank into pits which make them less likely to open and lose water A thick waxy cuticle on the leaves and stems reducing water loss through evaporation

Answer 23

Survival behaviours- a rabbit freezes when they think they have been seen Courtship- many animals exhibit elaborate courtship behaviour to attract a mate Seasonal behaviour-enable organisms to cope with changes in the environment

Answer 24

Migration-animal moves from one region to another and then back again when environmental conditions are more favourable. This may be for a better climate or a source of food Hibernation-a period of inactivity in which an animal‘s body temperature, heart rate and breathing slow down to conserve energy reducing the animals requirement for food

Answer 25

Poison production- reptiles produce venom to kill their prey and many plants produce poison in their lives to protect themselves Antibiotic production– some bacteria produce antibiotics to kill other species of bacteria in the surrounding areas

Answer 26

The tailfin of a whale and a fish perform the same role, when you look at them in detail their structures are very different They have adapted to perform the same function but have a different genetic origin

Answer 27

When unrelated species begin to share similar traits Similarities involved because the organism adapt to similar environments or other selection pressures Can also happen in plant species

Answer 28

These are factors that affect the organisms chance of survival or reproductive success (the ability to produce fertile offspring)

Answer 29

1) organisms within a species show variation in their characteristics that are caused by differences in their genes-new alleles can arise by mutation 2) organisms whose characteristics are best adapted to a selection pressure such as predation, competition or disease have an increased chance of surviving and successfully reproducing. Less well adapted organisms die or failed to reproduce- survival of the fittest 3) Successful organisms pass the allele including the advantages Characteristic onto there offspring. Organisms that possess the non-advantages allele are less likely to successfully pass it on. 4) process is repeated for every generation. Over time the population of individuals with the advantages adaptation increase. Therefore the frequency of the allele that code for these particular characteristics increase in the population gene pool 5) Over many generations and often involving multiple genes this process can lead to the evolution of a new species

Answer 30

Bacteria Viruses Protista Fungi

Answer 31

By their basic shape - they can be rod shaped, spiracle,, shapes, spiralled and corkscrewed By the cell wall - the two main types of bacteria cell walls have different structures and react differently to gram staining. Gram positive bacteria look purple/blue.. Gram negative bacteria appear red. This is useful because the type of cell walls affects how bacteria react to different antibiotics

Answer 32

Viruses are nonliving infectious agents with the basic structure of some genetic material surrounded by protein Viruses invade living cells where the genetic material of the virus takes over the host cell to make more viruses Viruses reproduce rapidly and evolved by developing adaptations to their hosts making them successful pathogens

Answer 33

They are viruses that attack bacteria by taking over the bacterial cells and using them to to replicate destroying the bacteria at the same time People have used bacteriophages to identify and treat some diseases Scientists consider viruses to be the ultimate parasite

Answer 34

Has a wide variety of feeding methods Include single celled organisms and cells grouped into colonies The Protista which cause disease are parasite -they use people animals as the host organism

Answer 35

Fungal disease is not a big problem for animals but are devastating to plants Are eukaryotic organisms, often multicellular, Many fungi are saprophytes meaning they feed on dead and decaying matter but some fungi are parasites feeding on living plants and animals Parasite bacteria cause communicable diseases because fungal infections often affect the leaves of the plants which stop them photosynthesising leading to killing of the plant Fungi reproduce with millions of tiny spores which spread huge distancesThis means they can spread widely and rapidly through plant crops

Answer 36

Destroying the host tissue directly producing toxins which damage host tissue

Answer 37

The viral genetic material gets into the host cell and is inserted into the host DNA. The virus uses the host cells to make new viruses which burst the cell destroying it and then spreading the infection to other cells Protester take over cells and destroy them open as the new generations emerge but they do not take over the genetic material of the cell. They digests and use the cell contents to reproduce Fungi digest living cells and destroy them. Combining with the response from the body to the damage, fungi gives symptoms

Answer 38

Ring rot Tobacco mosaic virus Potato blight Black sigatoka

Answer 39

A bacterial disease caused by gram-positive bacteria Damages leaves, tubers and fruit There is no cure, once Ring rot infect a field it cannot be used again for at least two years

Answer 40

A virus that infects tobacco plants and around 150 other species Damages leaves, flowers and fruit. Stunting growth and reducing yield can lead to total crop lost Resistant crops trains are available but there is no cure

Answer 41

Caused by the fungus like protests. Damaging leaves, tubers and fruits No cure but resistant strains, carefully manageable and chemical treatment to reduce infection risk

Answer 42

Banana disease caused by fungus Attacks and destroys the leaves. Digests the cells turning the leaves black. If plants are infected it can cause a 50% reduction in yield Resistant strains being developed, good husbandry and fungicide treatment can control the spread of the disease, no cure

Answer 43

Tuberculosis Bacterial meningitis HIV/AIDS Influenza Malaria Ring worm Athletes foot

Answer 44

Bacterial disease Damages and destroys lung tissue and suppresses the immune system, body is less able to fight of other diseases In people TB is both curable by antibiotics and a preventable by improving living standards and vaccinating

Answer 45

Bacterial infection of the meninges of the brain, can spread into the rest of the body causing septicaemia and rapid death Affects very young children and teenagers aged 15 to 19 Symptoms, a blotchy red/purple rash that does not disappear when glass is placed against it. This is symptoms of septicaemia. Antibiotics will cure the disease if delivered early. Vaccines can protect against forms of bacterial meningitis

Answer 46

AIDS is caused by HIV Target the T-helper cells in the immune system of the body. Gradually destroying the immune system so that person is open to other infections. HIV/AIDS is a retrovirus with RNA as its genetic material. Contains the enzyme reverse transcription Past on by bodily fluids No vaccine and no cure but anti-retroviral drugs slow the progress of the disease

Answer 47

A viral infection of the ciliated epithelium cells in the gases exchange system Can be fatal especially to young children and old people and people with chronic illnesses. Three main strains-A, B and C A is the most virulent and are classified further by the proteins on the surface They mutate regularly but the changes are usually small so having flu one year can have some immunity for the next Sometimes the changes in the surface antigens can lead to a flu epidermic or pandemic Vulnerable groups are vaccinated annually No Cure

Answer 48

Caused by the protoctista and spread by bites of infected mosquitoes They reproduce inside a female mosquitoes need to take blood for protein before she lays eggs there for passing on the parasite Invade the red blood cells, liver and even the Brain No vaccine and limited cause but prevention measures are effective Mosquitoes can be destroyed by insecticide and removing the standing water they breed in or by using mosquito nets preventing them from biting people and spreading the disease

Answer 49

A fungal disease affecting mammals Different fungi affect a different species Causes grey-white, crusty, infectious, circular areas ofSkin Not damaging but looks unsightly and may be itchy Antifungal creams are effective cures

Answer 50

Human fungal disease Form of human ringworm that grows on and digests the warm moist skin between the toes Causes cracking and scaling which is itchy and may become sore Antifungal cream is effective cure

Answer 51

Direct contact: Kissing or any contact with bodily fluids from another person (STI) Direct skin to skin contact (Athletes foot) Microorganisms from faeces transmitted on the hand (Diarrhoeal disease) Inoculation: Through a break in the skin (HIV/AIDS) From an animal bite (rabies) Through a punch a wound or sharing of needles (septicaemia) ingestion: Taking in contaminated food or drink or transferring pathogens to the mouth from the hands (Diarrhoeal disease)

Answer 52

Fomites: Inanimate objects such as bedding, socks or cosmetics can transfer pathogens (athletes foot) Droplet infections: Miniature droplets of saliva and mucus are expelled from your mouth as you talk, cough or sneeze. Droplets containing pathogens are breathed in my healthy individuals they can become infected (Influenza) Vectors: Transmits communicable pathogens from one house to another. Often animals but not always (Mosquitoes transmit malaria) Water can also act as a vector for diseases (diarrhoeal disease)

Answer 53

Overcrowded living and working conditions Poor nutrition A compromised immune system including having HIV/AIDS or needing immunosuppressant drugs Poor disposal of waste provide breeding grounds for vectors Climate change introduced new vectors a new diseases (malaria moving towards the UK due to temperature change) Culture and infrastructure - in many countries traditional medical practices can increase transmission Socio-economic factors - a lack of trained health workers and insufficient public warning when there is an outbreak of disease can increase transmission rate

Answer 54

Involves direct contact of a healthy plant with any part of a diseased plant examples include ring rot tobacco mosaic virus and blight

Answer 55

Infect the plants often leaves pathogens or reproductive spores in the soil Which would infect the next cop Examples include tobacco mosaic virus, Ring Road and black Sigatoka

Answer 56

Wind- bacteria, viruses and fungi spores can be carried by the wind (Black sigatoka blown between Caribbean Islands) Water- spores swim in the surface film of water water on leaves, raindrops splashes carry pathogens and spores (spores of potato blight which swim over films of water on the leaves ) Animals- insects and birds carry pathogen and spores from one plant to another as they feed. Humans-Pathogens and spores are transmitted by hands, clothing, fomites. (Tobacco mosaic virus survives for years on tobacco plants)

Answer 57

Planting varieties of crops that are susceptible to disease Overcrowding increases the likelihood of contact Poor minerals nutrition reduces resistance of plants Damp, warm conditions increase the survival and spread of pathogens and spores Climate change – anincreased rainfall and wind promote the spread of disease. Changing conditions allow animal vectors to spread to new areas.

Answer 58

Plants are not passive Receptors in the cell respond to molecules from the pathogen or to chemicals produced when the plant cell wall is attacked This stimulates the release of signalling molecules that turn on genes in the nucleus This triggers a cellular response which include producing defensive chemicals, sending alarm signals to unaffected cells to trigger their defences and physically strengthening the cells

Answer 59

When a plant is attacked by a pathogen it produces high levels of Celulose Celulose is synthesised and deposited between the cell walls and the cell membrane in cells next to the infected cells. They act as barriers preventing the pathogen entering the plant cell around infection site Celulose continues to be deposited in the cell walls after the initial infection but lignum is added in making the mechanical barrier to invasion even thicker and stronger Celulose blocks sieve plates in the phloem, ceiling of the infected parts and preventing the spread of pathogens Celulose is deposited in the plasmodesmata between infected cells and their neighbours, ceiling them off from healthy cells and preventing the spread of the pathogen

Answer 60

Plants produce powerful chemicals that either repel the insects vector of disease or kill invading pathogens. They are so powerful that we use them to repel insect, fungi and bacteria. Insect repellent- pine resin and citronella from lemon grass. Antibacterial compounds including antibiotics- EG: phenols - antiseptic made in different plants, lysosome - containing enzymes that break dawn the bacterial cell wall general toxins- some plans make chemicals that can break dawn to form cyanida compounds when the plant cell is attacked

Answer 61

The skin covers the body and prevents pathogens from entering. It has skin flora of healthy microorganisms outcompete pathogens on the surface of the skin. skin produces sebum, an oily substance that inhibits the growth of pathogens many of the body's tracts are lined with mucous membranes that secrete mucus trapping microorganisms and contains lysozymes which destroys cell walls. it also contains phagocytes that remove remaining pathogens. lysozymes in tears and urine and stomach also prevent pathogens getting into the body

Answer 62

coughs and sneezes ejects pathogen loaded mucus from the gases exchange system vomiting and diarrhoea expels the contents of the gut along with any pathogens

Answer 63

As the skin is breached, pathogens can enter the body. Blood clots rapidly to seal the wound, when platelets come in contact with collagen in the skin or the walls of the damaged blood vessel, they adhere and begin secreting several substances The clock dries out forming a hard tough scab to keep pathogens out. This is the first stage of window repair. Epidermal cells below the scab start to grow ceiling the wound permanently,Damaged blood vessels regrow Celulose fibres on deposited to give the new tissue strength. Once the new epidermis reaches normal thickness the scab falls off

Answer 64

Thromboplastin, an enzyme that triggers a cascade of reactions resulting in the formation of a blood clot Serotonin, which makes the smooth-muscle in the walls of the blood vessels contract, so they narrow and reduce the supply of blood to the area

Answer 65

Is a localised response to pathogens resulting in inflammation at the side of the wound. Inflammation is characterised by pain, heat, redness and swelling of the tissue Infections that are widespread can cause an inflammatory response of a whole body rash

Answer 66

They are activated in damaged tissue and release chemicals called histamines and cytokines

Answer 67

Histones make blood vessels dilate, Causing localised heat and redness. The rising temperature helps prevent pathogens reproducing Makes blood vessel walls more leaky so blood plasma is forced out, once forced out of the blood it is known as tissue fluid. Tissue fluid causes swelling and pain

Answer 68

Cytokines attract the white blood cells (phagocyte) to the site. They dispose of pathogens by phagocytosis

Answer 69

Or adaptations to prevent pathogens growingI want to destroy them Fever Phagocytosis

Answer 70

Normal body temperature is around 37°C and is maintained by the hypothalamus in your brain When a pathogen invade your body, Cytokines stimulate your hypothalamus to reset the thermostat and your temperature goes up, useful adaptations because: Most pathogens reproduce best at below 37°C. Higher temperatures inhibit pathogen reproduction The specific immune system works faster at higher temperatures

Answer 71

Phagocytes are specialised white cells that engulf and destroy pathogens Two types of phagocytes - neutrophils and macrophages Pus in a spot, cut or wound consisting of dead neutrophils and pathogens

Answer 72

Pathogen produce chemicals that attract phagocytes Phagocytes recognise non-human proteins on the pathogen. This is a response not to a specific type of pathogen but simply a cell or organism that is non-self The phagocyte engulfs the pathogen and encloses it in a vacuole called a phagosome The phagosome combines with lysosomes to form a phagolysosome Enzymes from the lysosome digestion and destroy the pathogen Neutrophils Takes 10 minutes to undergo phagocytosis

Answer 73

Pathogen produce chemicals that attract phagocytes Phagocytes recognise non-human proteins on the pathogen. This is a response not to a specific type of pathogen but simply a cell or organism that is non-self The Phagocytes engulfs the pathogen and encloses it in a vacuole called a phagosome The phagosome combines with lysosomes to form a phagolysosome Enzymes from the lysosome Digest and destroy the pathogen macrophages combine antigens from the pathogen surface membrane with special glycoproteins in the cytoplasm called major histocompatibility complex The major histocompatibility complex moves the pathogen antigens to the macrophages own surface membrane becoming an antigen presenting cell This antigens stimulate the specific immune system

Answer 74

Phagocytes that have engulfed a pathogen produce cytokines Cytokines act as cell signalling molecules, informing other phagocytes that the body is under attack and stimulate them to move to the sight of infection or inflammation Cytokines can also increase body temperature and stimulate the specific immune system

Answer 75

Chemicals that bind to pathogens and tag them so they can be easily recognised by phagocytes Phagocytes have receptors on the cell membrane to find common opsonins and the phagocyte then engulfs the pathogen

Answer 76

how the body recognise the different between self antigen on your own cells and non-self antigens of the pathogens antigens trigger an immune response with antibodies

Answer 77

is slower than the non-specific responses but has immune memory cells meaning it reacts quickly to a second invasion by the same pathogen

Answer 78

y shaped glycoproteins called immunoglobulins binds to specific antigens on the pathogen which had triggered the immune response. millions of antibodies and a specific antibody for each antigen made of 2 identical long polypeptide chains called the heavy chains and 2 shorter identical chains called the light chains chains are held together by disulfide bridges and there are also disulfide bridges between the polypeptide chains the binding site of antibody to the antigen is an are of 110 amino acids on both the heavy and light chains is known as the variable site. it is different for each antibody and gives the antibody its specificity. the rest of the antibody is always the same known as the constant region the binding of a antibody to a antigen is called antigen-antibody complex hinge region of the antibody provides flexibility, allowing it to bind 2 antigens at its antigen-binding sites

Answer 79

The antibody of the antigen-antibody complex acts as an option so the complex is easily engulfed and digested by phagocytes Most pathogens can no longer effectively invade the host cell once they are part of a antigen-antibody complex Antibodies act as agglutinins causing pathogen carrying antigen-antibody complexes to clump together. This helps prevent them spreading throughout the body and making it easier for phagocytes to engulf a number of pathogens at the same time Antibodies act as antitoxins, binding to the toxins produced by pathogens and making them harmless

Answer 80

B lymphocytes matured in the bone marrow T lymphocytes matured in the Thymus gland

Answer 81

T-helper cells T killer cells T memory cells T regulator cells

Answer 82

They have CD4 receptors on the cell surface membrane which binds to the surface antigen is on antigen-presenting cells They produce interleukins which are a type of cytokine which stimulate the activity of B cells therefore increasing antibody production, stimulates production of other types of T cells and attracts and stimulate macrophages to ingest pathogens with antigen-antibody complex

Answer 83

Destroy the pathogen carrying the antigen Produce a chemical called perforin which kills the pathogen by making holes in the cell membrane so it is freely permeable

Answer 84

Lives for a long time and are part of the immunological memory. If they meet an antigen a second time, they divide rapidly to form a huge number of clones of T killer cells that destroyed the pathogen

Answer 85

Cells suppress the immune system, acting to control and regulate it They stop the immune response once a pathogen has been eliminated and make sure the body recognises self antigens and does not set up an autoimmune response Interleukins are important in this control

Answer 86

Plasma cells B effector cells B memory cells

Answer 87

Produce antibodies to a particular antigen and releases them into the circulation Active Plasma cells only lives for a few days but produces around 2000 antibodies per second while it is alive and active

Answer 88

Divide to form the plasma cell clones

Answer 89

Lives for a very long time and provides The immunological memory Program to remember a specific antigen and enable the body to make a rapid response when a pathogen carrying that antigen is encountered again

Answer 90

T lymphocytes respond to the cells of an organism that has been changed in some way, by a viral infection, by antigen processing or by mutation and two cells from transplanted tissue. The cell mediated response is particularly important against viruses and early cancer

Answer 91

1) In the non-specific defence system, macrophages engulf and digest pathogens in phagocytosis. They process the antigens from the surface of the pathogen to form antigen-presenting cells 2) The receptors of some of the T-helper cells fit the antigens. These T-helper cells become activated and produce interleukins which stimulate more T cells to divide rapidly by mitosis. They form clones of identical activated T-helper cells that all carry the right antigen to bind to a particular pathogen 3) The cloned T cells may: Develop into T memory cells, which give a rapid responseIf this pathogen invade the body again Produce interleukins that stimulate phagocytosis Produce interleukins that stimulate b cells to divide Stimulate the development of a clone of T killer cells that are specific for the Presented antigen and then destroy infected cells

Answer 92

The body responds to antigens found outside the cell for example in bacteria and fungi and to antigen-presenting cells. Produces antibodies that are soluble in blood and tissue fluid and are not attached to cells B lymphocytes have antibodies on their cell surface membrane and there are millions of different types of B lymphocytes, each with different antibodies. When a pathogen enters the body it will carry specific antigens or produced toxins that act as antigens. B-cell with the complimentary antibody will bind to the antigens on the pathogen or to the free antigens. The B-cell engulfs and processes the antigens to become an antigen presenting cell

Answer 93

1) activated T-helper cells bind to the B-cell antigen-presenting cell. This is clonal selection –the point at which the B-cell with the correct anti-body to overcome a particular antigen is selected for cloning 2) interleukins produced by the activated T-helper cells activate the B cells 3) activated B cells divide by mitosis to give clone of plasma cells and B memory cells –clonal expansion 4) Clone plasma cells produce antibodies that fight the antigens on the surface of the pathogen, bind to the antigens and disable them or act as opsonins or agglutinins. the primary response and can take days or weeks to become fully effective against a pathogen 5) Some cloned B cells develop into the memory cells. If the body is infected by the same pathogen again the B memory cells divide rapidly to form plasma cell clones. They produce the right antibodies and wipe out the pathogen is very quickly, before it can cause the symptoms of disease- secondary immunity response

Answer 94

Sometimes the main system stops recognising self cells and start attacking healthy body tissue Appears to be a genetic tendency in some families, sometimes the Muinn system responds abnormally to mild pathogen is all normal body microorganisms and in some cases the T regulator so do not work effectively Can cause chronic inflammation or the complete breakdown and destruction of healthy tissue. Immunosuppressant drugs, Prevents the immune system working can be used as treatment

Answer 95

When your immune system is activated and antibodies are formed which result in the Destruction of the antigen The main system produces TNB memory cells so if you meet a pathogen for a second time, your immune system recognises the antigen and can immediately destroy the pathogen Known as active because the body has its self acted to produce antibodies and or memory cells

Answer 96

The immune system of a newborn baby is not mature and it cannot make antibodies for the first couple of months Some antibodies cross the placenta from the mother to her fetus while the baby is in the uterus, so it has some immunity to diseases at birth The first milk a mammalian mother makes is called Colostrum which is very high in antibodies. For the first few days breastfed babies will have the same Antibody protection against diseases as the mother Lasts until the immune system of the baby begins to make its own antibodies. The antibodies the baby receives from the mother are likely to be relative to pathogen is in its environment

Answer 97

For certain potentially fatal diseases, antibodies are formed in one individual extracted and then injected into the bloodstream of another individual Temporary immunity-it doesn’t last long but can be life-saving For example tetanus And rabies can be treated like this

Answer 98

Immune system of the body is stimulated to make its own antibodies to a safe form of an antigen (a vaccine), which is injected into the bloodstream (vaccination) The antigen is not usually the normal live pathogen May last a year, a few years or a lifetime Sometimes boosters are needed to increase the time you are immune to the disease

Answer 99

1) The pathogen is made safe in a number of ways so that the antigen are intact but there is no risk of infection 2) Small amounts of the safe antigen known as a vaccine are injected into the blood 3) The primary immune response is triggered by the foreign antigens and your body produces antibodies and memory cells as if you were infected with a live pathogen 4) If you came into contact with a live pathogen, the secondary immune response is triggered and you destroy the pathogen rapidly before you suffer symptoms of the disease

Answer 100

Killed or inactivated bacteria and virus Attenuated strains of life bacteria or virus for example, rubella, BCG against TB, polio Toxin molecules have been altered and detoxified: tetanus, diphtheria Isolated antigens extracted from the pathogen Genetically engineered antigens, the hepatitis B vaccine

Answer 101

An epidermic is when a communicable disease spreads rapidly to a lot of people at a local or national level An epidermic is when the same disease spreads rapidly across a number of continents and countries

Answer 102

Malaria- Plasmodium, The parasite that causes malaria. Very invasive-it Spends time inside the Erythrocyte so it is protected by self antigens from the Immune system and within an infected individual it’s antigens reshuffle HIV - Causes AIDS- it enters the microcrophages and T-helper cells, so it has disabled the immune system itself

Answer 103

First widely used, effective, safe antibiotic capable of curing bacterial diseases From a mould, famously discovered by Alexander Fleming Fleming so what the mould did to his bacteria but could not expect enough to test its potential

Answer 104

From a wide range of sources Scientist designed drugs using complex computer programs. They build three-dimensional models of key molecules in the body and of pathogens and antigen systems allowing models of potential drugs to be built up which are targeting the particular areas of the pathogen Computers are also used to search through enormous libraries of chemicals to isolate any with potential useful action against a specific group of features of a pathogen or mutated cells in a cancer Analysis of genomes of pathogens and GenesWhich have been linked to cancers enable Scientists to attack vulnerabilities Many drugs most commonly used in medicine are still derived from or based on Bioactive compounds discovered in plants, micro organisms or other forms of life Deforestation of rainforest might lead to extinction of life-saving plants, animals and microorganisms which can give us key life-saving drugs

Answer 105

Personalised medicine- a combination of drugs that work with your individual combinations of genetic and diseases The science of interweaving knowledge of drug actions with personal genetic material In the future this type of treatment, where the clinicians look at the genome of the patient and the genome of the invading pathogen before deciding how to treat them

Answer 106

The technique of genetic engineering, can develop populations of bacteria to produce much- needed drugs that would otherwise be too rare, too expensive or just not available Nanotechnology, where tiny, non-natural particles are used for biological purposes

Answer 107

Antibiotics interfere with the metabolism of the bacteria without affecting the metabolism of human cells

Answer 108

Antibiotics work because a bacterium has a binding site for the drug and a metabolic pathway that is affected by the drug A random mutation during bacterial reproduction produces a bacterium that is not affected by antibiotics This bacteria is best fitted to survive and reproduce passing on the antibiotic resistant mutation to the daughter cells Bacteria reproduce very rapidly, so a mutation occurs it does not take long to grow a big population of antibiotic resistant bacteria

Answer 109

Minimising the use of antibiotics and insuring that every course of antibiotics is completed to reduce the risk of resistant individual surviving and developing into a resistance strain population Good hygiene in hospitals, care homes and in general-this has a major impact on the spread of infections, including antibiotic resistant strains

Answer 110

The variety of living organisms present in an area. Include plants, animals, fungi and other living things

Answer 111

Biodiversity is essential in maintaining a balanced ecosystem for all organisms All species are interconnected – they depend on one another In regions of reduced biodiversity, connections may not be present which eventually harms all species in the ecosystem We rely on balanced ecosystems as they provide us with the food, oxygen and other materials we need to survive Human activities can lead to a reduction in biodiversity

Answer 112

Tropical, moist regions have the most biodiversity The U.K.’s temperate climate has less diversity Very cold areas such as the Arctic or very dry areas such as deserts have the least biodiversity Generally the closer the region is to the equator the greater the biodiversity

Answer 113

Important role in conservation It informs scientists of the species that are present therefore providing a baseline for the level of diversity in an area From this information the effects of any changes to an environment can be measured These may include the effects of human activity, disease or climate change

Answer 114

Habitat biodiversity Species diversity Genetic diversity

Answer 115

Refers to the number of different habitats found within an area Each habitat can support a number of different species, therefore the greater the habitat biodiversity the greater the species diversity within that area The UK has A large number of habitat types therefore it has a large habitat biodiversity, while Antarctica covered almost entirely in an ice sheet has a very low habitat biodiversity and very few species The countryside is habitat rich, perhaps with a river, woodland, hedgerows and wild grassland, will be more species rich than farmed countryside.

Answer 116

Species richness-the number of different species living in a particular area Species evenness-a comparison of the number of individuals of each species living in A community

Answer 117

Variety of genes that make up the species Many of these genes are the same for all individuals within a species. However for many genes, different versions exist leading to genetic biodiversity within a species Genetic biodiversity within a species can lead to quite different characteristics being exhibited Greater genetic biodiversity within a species allow for better adaptations to a changing environment and is more likely to result in individuals who are resistant to disease

Answer 118

Means taking measurements of a limited number of individual organisms present in a particular area Sampling can be used to estimate the number of organisms in an area without counting them. The number of individuals of an species present in an area is known as the abundance of organism. Sampling can be used to measure particular characteristics of an organism After measuring a sample, you can use the results of the sample to make Estimation is about the number of organisms or characteristics throughout the habitat Two types of sampling-random and non-random

Answer 119

Selecting individuals by chance. Each individual in the population has an equal likelihood of selection To decide which organism to study random number Computers can be used. You have no involvement in deciding which organism to investigate. For example: 1) mark out a grid on the area using two tape measures laid at right angles 2) use random number generator to determine the x-coordinate and the Y coordinate on your grid 3) take a sample add each of the coordinates generated

Answer 120

Opportunistic Stratified Systematic

Answer 121

Weakest form of sampling as it may not be representative of the population. Uses organisms that are conveniently available

Answer 122

Some populations can be divided into a number of strata (subgroups) based on particular characteristics The population might be separated into male and female. A random sample is then taken from each of these strata populations for its size

Answer 123

Different areas within an overall habitat are identified, which are then sampled separately Systematic sampling is often carried out using a line or a belt transect A line transect involves marking a line along the ground between two poles and taking samples at specific points, can include describing all organisms touching the line or a distance from the line A belt transect provides more information–Two parallel lines are marked and samples are taken on the area between the two lines

Answer 124

The selection process may be biased. This may be by accident or may occur deliberately. The effects of sampling bias can be reduced to using random sampling, where human involvement in choosing the samples removed

Answer 125

Organisms selected may, By chance not be representative of the whole population. Chance can never be completely removed from the process but its effects can be minimised by using a large sample size. The greater the number of individuals studied, the lower the probability that chance will influence the result. Larger the sample size the more reliable the result

Answer 126

All living organisms must be handled carefully and for a short time period as possible. As soon as any sample animals have been identified, counted and measured if required they must be released back into the habitat at the point they were collected Sweep nets are used to catch insects in areas of long grass Pitfall traps are used to catch small, crawling invertebrates such as Beatles. A whole is dug in the ground which insects fall into , deep enough that they don’t escape and covered with the roof structure propped above so that the trap does not fill with rainwater Tree beating is used to take samples of invertebrates living in a tree or bush. A large white cloth is stretched out under the tree, the tree is shaken or beaten to dislodge the invertebrates. The animals will fall onto the sheet where they are collected and studied

Answer 127

Using a quadrat, which can also be used to pinpoint an area in which the sample of plant can be collected Quadrats can also be used to sample slow-moving animals such as mussels To connect the most valid representative sample of an area, contracts should be used following a random sampling technique. To study how the presents and distribution of organisms across an area of land varies the quad rats can be placed systematically along a line transect

Answer 128

Point quadrat- consists of a wooden frame containing horizontal bar. At set intervals along the bar, long points can be pushed through the wall to reach the ground. Each species of plant point touches is recorded Frame quadrat- consists of a square frame divided into a grid of the equal sections. The type and number of species within each section of the quadrant is recorded

Answer 129

By using a combination of techniques to try to identify all the species present in the habitat A list should be compiled of each species identified. The total number of species can then be calculated. To enable scientists to accurately identify organisms, identification keys are often used. They may contain images to identify the organisms, or a series of questions which classify an organism into a particular species based on the presence of a number of identifying characteristics

Answer 130

Density- if individual large plants can be seen clearly clearly count the number of them in one by one squared quadrat. This will give you the density per square metre. An absolute measure, not an estimate Frequency- used to where individual members of species are hard to count. Using the small grids within a quadrat count the number of squares a particular species is present in. If it is 100 square quadrant, each square represents 1%. If it is a 25 squared quadrat, Each square represents 4% of the study area Percentage cover - Use for speed as loads of data can be collected quickly. Useful when particular species is abundant or difficult to count an estimate by eye of the area within a quadrat that a particular plant species cover

Answer 131

Animals are constantly moving through a habitat and others may be hiding it can be difficult to accurately determine their population size Technique known as capture Mark release recapture is often used to estimate a population size Involves capturing as many individuals of a species in an area as possible, the organisms are marked and then released back into the community. Time is allowed for the organism to redistribute themselves throughout the habitat before another sample of animals is collected. By comparing the number of marked individuals with the number of non-marked individualsScientists can estimate population size. The greater the number of marked individuals recaptured the smaller the population

Answer 132

Involves capturing as many individuals of a species in an area as possible, the organisms are marked and then released back into the community. Time is allowed for the organism to redistribute themselves throughout the habitat before another sample of animals is collected. By comparing the number of marked individuals with the number of non-marked individuals Scientists can estimate population size. The greater the number of marked individuals recaptured the smaller the population

Answer 133

Nonliving conditions in a habitat have a direct effect on the living organisms that reside there. Amount of light and water availability. Enables them to draw conclusions about the organisms present and the conditions they need to survive, scientist normally measure these conditions at every measuring point

Answer 134

Wind speed- anemometer Light intensity-light meter Relative humidity- humidity sensor PH- pH probe Temperature- temperature probe Oxygen content in water- dissolved oxygen probe

Answer 135

Rapid changes can be detected Human error in taking a reading is reduced A high degree of precision can often be achieved Data can be stored and tracked on a computer

Answer 136

Takes into account both species richness and species evenness Scientists normally have to estimate population size using a variety of sampling techniques such as using a quadrat to estimate the population of plant species in an area Simpsons index of diversity always results in a value between zero and one, with zero represents no diversity and the value of one represents infinite diversity. The higher the value of Simpsons index of diversity the more diverse the habitat

Answer 137

Relatively few successful species Stressful and extreme with relatively few ecological niches for an environment Relatively few species live in the habitat, often with very specific adaptations for the environment Relatively simple food web Major effects on the ecosystem as a whole

Answer 138

A large number of successful species Relatively benign/not stressful, with more ecological niches Many species live in the habitat, often with few specific adaptations to the environment A complex food webs Often relatively small effect on the ecosystem as a whole

Answer 139

Some organisms that are present in habitat can be highly adapted to the extreme environments of the habitat These organisms may not survive elsewhere therefore it is important to conserve some habitats with low biodiversity in order to conserve rare species

Answer 140

Within a species, individuals have very little variation in their DNA All members of the species share the same genes. They may have different versions of some of these genes called alleles The different values among individuals of a species creates genetic biodiversity within the species. The more alleles present in a population, the more genetic biodiversity in the population Species that contain greater genetic biodiversity are likely to be able to adapt to changes to the environment and are less likely to become extinct Because there are likely to be some organisms within the population that carry an advantages alleles

Answer 141

The number of possible alleles in a population must also increase Mutations in the DNA of an organism creating a new allele Interbreeding between different populations within a species. When an individual migrate from one population breeds with a member of another population, alleles are transferred between the two populations-gene flow

Answer 142

The number of possible alleles in a population must also decrease Selective breeding, where only a few individuals within a population are selected for their advantages characteristics and bread. Captive breeding programs in zoos and conservation centres, where only a small number of captive individuals of a species are available for breeding Artificial cloning Natural selection- species will evolve to contain primarily the alleles which code for advantages characteristics, overtime values coding for less advantages characteristics will be lost from the population Genetic bottlenecking - few individuals within a population survive an event or change, reducing the gene pool. Only the values of the surviving members of the population are available to be passed on to offspring Founders effect -what a small number of individuals create a new colony-geographically isolated from the original. The gene pool of the new population is smaller Genetic drift –the random nature of alleles being passed on from parents to their offspring, the frequency of occurrence of an allele will change. More pronounced in population with a low genetic biodiversity

Answer 143

They have more than one allele Most genes are monomorphic- A single allele exist for this gene. Insures that the basic structure of individuals within a species remain constant The greater the proportion of polymorphic gene loci The greater the genetic biodiversity within the species

Answer 144

Number of polymorphic gene loci ——————————————————— Total number of Loci The locus of a gene refers to the position of the gene on a chromosome

Answer 145

Deforestation- permanent removal of large area of forest to provide wood for building a few and to create space for roads Agriculture – an increasing amount of land has to be formed in order to feed the growing population resulting in large amounts of land being cleared and in many tasted planted with a single crop Climate change-evidence that the release of carbon dioxide and other pollutants into the atmosphere is increasing global temperature

Answer 146

Directly reduces the number of trees present in an area If only a specific type of tree is failed, the species diversity is reduced but less usable trees may be left intact It reduces the number of animal species present in an area as it destroys their habitat, including their food source and home. This reduces the number of other animal species that are present by reducing or removing their food sauce Animals are forced to migrate to other areas to ensure their survival resulting in the biodiversity of neighbouring areas increase

Answer 147

Farmers will only grow a few different species of crop plants, or readjust a few species of animals. Farmers often select the species spread on characteristics to give a high yield. The selection of only a few species greatly reduces the biodiversity in the area In order to be economically viable, once the farmers have selected the desired species, a number of techniques are used to produce as many of the desired species as possible, maximising food production

Answer 148

Deforestation –to increase the area of land available for growing crops or rearing animals Removal of hedgerows - as a result of mechanisation, farmers remove hedge Rose to enable them to use large machinery to help them plant, fertilise and harvest crops. Also frees up extra land for crop growing. Reduces the number of plant species present in an area and destroys the habitat of animals and invertebrate Use of chemicals such as pesticides and herbicides - are used to kill pests that can eat the cropper live on the animal, reduce the species diversity directly as it destroys the pest species and indirectly by destroying the food source of other organisms Herbicides are used to kill weeds. The weed is another plant growing in an area where it is not wanted. Weeds are destroyed as they compete with the cultivated plant for light minerals and water. Thereby plant diversity is reduced directly and animal diversity may also be reduced by the removal of an important food source Mono culture - farm specialise in the production of only one crop, with many acres of land being used for the growth of one species leading to the lowering of biodiversity as only one species of plant is present. As relatively few animal species will be supported by only one type of plants

Answer 149

The warming trend over the last 50 years is nearly twice that of the previous 100 years Since 1961, the average temperature of the global ocean down to depth of 3 km has increased. The ocean has been absorbing more than 80% of the heat added to climate system causing seawater to expand and contributing to sea level rise Average Arctic temperatures have increased At almost twice the global average rate in the past hundred years Mountain glaciers and snow cover have declined on average in both hemispheres. Widespread declines in glaciers and an ice caps have contributed to sea level rise Long-term upward trend to the amount of precipitation has been observed over many Regions

Answer 150

The melting of the polar ice caps can lead to the extinction of the few plants and animal species living in these regions. Some species of animals present in the Arctic on migrating further and further north to find favourable conditions. Increasing global temperatures would allow temperate plants and animal species to live further north than currently Increasing Sea levels from melting ice caps and the thermal expansion of oceans could flood low-lying land, reducing the available territorial habitat. Salt water would flow further up river reducing the habitats of freshwater plants and animals living in the river and surrounding areas Higher temperatures and less Rainfall would result in some plant species failing to survive leading to Drought resistant species becoming more dominant. Loss of Non-drought resistant species of plants would lead to the loss of some animal species depending on them as food

Answer 151

The presence of different animals and plants in our environment in riches our lives The natural world provides inspiration for people such as musicians and writers, who intern provide pleasure for many other people Studies have shown that patient recovers more rapidly from stress and injury when they are supported by plants and a relatively neutral environment

Answer 152

Soil erosion and desertification may occur as a result of deforestation. These reduce a country’s ability to grow crops and feed its people, which can lead to resources an economic dependency on other nations Large-scale habitats and biodiversity Loss means that species with potential economic importance may become extinct before they are even discovered, chemically or Medicine really useful High biodiversity provides protection against abiotic stress and disease. When biodiversity is not maintained a change in conditions or a disease can destroy entire crops Areas rich in biodiversity provides a pleasure, attractive environment that people can enjoy. Highly biodiversity areas can promote tourism in the region which is associated with economic advantage The greater the diversity in an ecosystem, the greater the potential for the manufacture of different products in the future which may be beneficial to humans

Answer 153

All organisms are interdependent on others for their survival. The removal of one species may have a significant effect on others Some species play a key role in maintaining the structure of an ecological Community. These are known as keystone species. They have a disproportionately large effect on the environment relative to the abundance. They affect many other organisms in an ecosystem and help to determine the species richness and evenness in the community. If a keystone species is removed the habitat is drastically changed. All other species are affected and some may disappear altogether.Essential to protect keystone species to maintain biodiversity

Answer 154

In many countries the natural habitat is created by human intervention andThe management of land This enables rare species to survive

Answer 155

The name given to the preservation and careful management of the environment and other natural resources By conserving the natural habitat in an area, organisms chances of survival are maintained allowing them to reproduce Consequently species and genetic diversity can be safeguarded

Answer 156

In situ conservation-within the natural habitat Ex situ conservation-out of the natural habitat

Answer 157

Extinct - no organism of the species exist anywhere in the world Extinct in the world –organisms of the species only exist in captivity Endangered- a species that is in danger of extinction Vulnerable- a species that is considered likely to become endangered in the future Nonthreatened and categories of least concern follow below

Answer 158

Many conservation techniques focus on increasing the number of organisms from species that are classified as endangered Scientists are promoted to practice sustainable development- economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs

Answer 159

Takes place inside an organisms natural habitat Maintains not only the genetic diversity of species but also the evolutionary adaptations that enable a species to adapt continuously to changing environmental conditions such as a pest population or climate By allowing the endangered species to interact with other species, It preserves the interdependent relationship present in a habitat, therefore interlinked species may be preserved In situ conservation is generally cheaper than ex situ conservation Marine (saltwater), aquatic (freshwater) and territorial natural reserves are examples of areas specifically designed for the conservation of wildlife

Answer 160

Control grazing - only allowing livestock to graze a particular area of land for a certain period of time to allow species Time to recover or keeping a controlled number of animals in a habitat to maintain it Controlling poaching - this increase creating defences to prevent access, issuing fines or more drastic steps such as the removal of rhino horns Feeding animals – this technique can help to ensure more organisms survive to reproductive age Reintroduction of species- adding species to areas that have become locally extinct, or whose numbers have declined significantly Calling or removing invasive species – aninvasive species is an organism that is not native to an area and have negative effects on the economy, environment or health. These organisms compete with native species for resources

Answer 161

Marine reserves are vital in preserving species - rich area such as coral reefs which are being devastated by non-sustainable fishing methods Purpose of marine reserves is not to prevent fishermen from visiting the entire area but to create areas of refuge within which populations can build up and re-populate adjacent areas. Large areas of sea are required for marine reserves as the target species often move long distances or breed in geographically different areas

Answer 162

Plant species can grow successfully in botanic Gardens. Hate the species are actively managed to provide them with the best resources to grow, such as the provision of soil nutrients, sufficient water in and the removal or prevention of pests The majority of species are not conserved. Many wild relative of selectively bred crop species are underrepresented amongst conserve species. These wild species are a potential source of genes, with resistance to disease, pests and parasites

Answer 163

A seed bank is an example of a gene bank-a store of genetic material Seeds of carefully stored so that new plants can be grown in the future. They are dried and stored at temperatures of -20°C to maintain their viability by slowing down the rate at which they lose their ability to germinate. All temperatures seeds and some tropical seeds can be stored this way being viable for centuries providing a backup against extinction of wild plants The doomsday vault in Norway door seeds in the permafrost and already holds around 800,000 species, eventually having 3 million different types of seeds and aims to provide a back up against the extinction of plants in the wild by storing seeds for future reintroduction and research for breeding and for genetic engineering in the future Seed banks don’t work for all plants, some seeds die when dried and frozen and the seeds of the most tropical rainforest trees fall into this category

Answer 164

Captive breeding programs produce offspring of species in a human controlled environment Often run managed by zoos and aquatic centres. Several species are now solely represented by animals in captivity newcomer scientists working on captive breeding programs aimed to create a stable, healthy population Of a species and then generally reintroduced to species back into natural habitat Provides the animals with shelter, and abundant supply of nutritious food, an absence of predators and veterinary treatment.Suitable breeding partners or semen can be imported from other zoos if not available within the zoos own population

Answer 165

Maintaining genetic diversity within a captive breeding population can be difficult. Only a small number of breeding partners are available, problems related to interbreeding can occur. An international catalogue is maintained, detailing genealogical data on individuals. Mating can be arranged to ensure that genetic diversity is maximised. Techniques such as artificial insemination, embryo transfer and long-term higher genic storage of embryos allow new genetic lines to be introduced without transporting the adult to new locations and does not require animal corporation

Answer 166

Diseases- there may be a loss of resistance to local diseases in captive populations. Maybe new diseases might exist in the wild to which captive animals have yet to develop resistance Behaviour- some behaviour is innate but much has to be learned through coping or experience. In an earlier case of reintroduction a number of monkeys starved because they had no concept of having to search for food. Genetic race- the genetic make up of captive animals can become so different from the original population that the two populations cannot interbreed Habitat – in many cases the natural habitat must first be restored to allow captive populations to be reintroduced. If only a small habitat exists there is already as many individuals as the habitat can support already exist. This can lead to stress and tension as individuals fight for limited territory and resources such as food

Answer 167

Intergovernmental organisation that assist in securing agreements between nations Once a year the International union for the conservation of nature publishes the red list detailing the current conservation status of threatened animals allowing countries to work together to conserve these species Also involved in the establishment of the Convention on International trade in endangered species- Treaty regulates the International trade of wild plant and animal specimens and their products. As the trade in wild animals and plants crosses borders between countries the effect of regulate it requires international corporation to safeguard certain species from over exploitation

Answer 168

Known as the Earth Summit The conservation of biological diversity requires countries to develop national strategies for sustainable development does ensure the maintenance of biodiversity The United Nations framework Convention on climate change is an agreement between nations to take steps to stabilise greenhouse gas concentrations within the atmosphere The United Nations Convention to combat desertification aims to prevent the transformation of fertile land into desert and reduce the effects of drought through programs of international corporation

Answer 169

Many conservation schemes are set up at more local level Operated from 1991 to 2014, offered governmental payments to farmers and other land managers to enhance and conserve the English landscape. Its general aim was to make conservation a part on natural farming and land management practice Scheme has been replaced by the environmental stewardship scheme

Answer 170

Sustaining the beauty and diversity of the landscape Improving, extending and creating wildlife habitats Restoring neglected land and conserving archaeological and historical features Improving opportunities for countryside enjoyment

Module 4 – Biodiversity, evolution and disease Flashcards

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