Module 4 Flashcards

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1
Q

Define the term parasite

A
  • Lives in host
  • Gains nutrition from host
  • At expense of/harms host (causes disease)
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2
Q

Explain why the human boby’s primary defences do not prevent the entry of Plasmodium into the body

A
  • Mosquito (vector) feeds on blood
  • Mosquito pierces skin
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3
Q

Suggest why malaria is much more common in tropical areas than in other parts of the world

A
  • Suitable climate for mosquito (vector)
  • More mosquitos live there
  • Relatively poor so methods of prevention less effective/ lack of education
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4
Q

Suggest two reasons why governments in parts of the world other than tropical areas, are also becoming increasingly concerned about malaria

A
  • Global warming may result in spread to other parts of the world
  • Increased movement of (infected) people
  • (non-malaria) countries fund anti-malaria measures via international aid
  • Resistance of parasite to drugs/ resistance of mosquito to insecticide
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5
Q

Suggest why erythrocytes that contain Plasmodium are more likely to be destroyed by phagocytosis than healthy erythrocytes

A
  • (different) chemical that attract phagocytes
  • cytokines/histamine/interleukin released
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6
Q

Describe the differences between globular and fibrous protein using haemoglobin and collagen as examples

A

GLOBULAR:

  • ball (shaped)/ spherical
  • hydrophilic (R-) groups/ regions on outside (of 3-D structure)/ hydrophobic (R-) groups/regions on inside
  • form H-bonds with water
  • soluble
  • haemoglobin carrier/ transports O2/CO2
  • haemoglobin contains prosthetic group/ haem/ Fe2+/ iron ion (to allow O2 to be carried)
  • (polypeptide chains within) haemoglobin have tertiary strcuture (in a ball shape)

FIBROUS:

  • linear/ long (chain)
  • chains can form H-bonds with adjacent chains within molecule
  • insoluble/ few hydrophilic groups
  • strong/ provides strength
  • have structural role
  • collagen forms part of cartilage/connective tissue/ bronchi/ bronchioles
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7
Q

Describe how the structure of antibodies allows them to perform their function

A
  • 2 light chains and 2 heavy chains / 4 polypeptide chains
  • variable region allows binding/ attachement to antigen
  • two variable regions allow binding of more than one (of the same) antigen
  • variable region on different antibodies allow specificity to different antigens
  • constant region allows recognition by/ attachment to/ binding to, (named) phagocytes
  • hinge (region) allows flexibility
  • disulfide, bonds/bridges, hold polypeptides/ light and heavy cains, together
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8
Q

Describe the process of agglutination

A
  • clump/bind together, many pathogens
  • (clump) too large, to enter (host) cell/ cross membrane
  • increase likelihood of being consumed by (named) phagocyte/ more can be consumed by phagocyte at once
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9
Q

In a piece of school homework a student wrote:
‘Bacteria can evolve quickly and many are now immune to antibiotics’
Explain why the students use of the word immune was incorrect

A
  • immunity involves/baceteria do not have, lymphocytes/ antibodies/ white blood cells/ an immune system/ memory cells/ plasma cells
  • correct term is resistant
  • bacteria are unicellular/ only multicellular organisms (can) have an immune system
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10
Q

Why are phagocytes described as a secondary defence?

A

(involved) after, pathogen, has entered the body

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11
Q

Why is the response involving phagocytes regarded as non-specific?

A

(phagocytes) able to digest/break down/ engulf/ target/ deal with, a range of/ many different, pathogens

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12
Q

Describe the process by which a pathogen is destroyed after it has become attached to the surface of a phagocyte

A
  • (pathogen) engulfed/ enveloped/ surrounded by cytoplasm (of phagocyte)
  • endocytosis/phagocytosis
  • (formation) of phagosome/ phagocytic vacuole
  • (phago) lysosomes
  • (lysosomes/phagosomes) move towards/ fuse with (each other)
  • (named) enzyme/ lysins/ hydrogen peroxide/ free radicals (in lysosomes)
  • (pathogen) digested/broken down/ hydrolysed
  • to amino acid/ sugar/ glucose/ glycerol/fatty acids
    or unwanted products removed (by exocytosis)
  • cytoskeleton involvement in (endocytosis/ movement of vesicles)
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13
Q

Describe how TB is transmitted from one individual to another

A
  • droplets (containing pathogen)
  • (released by) coughing/sneezing
  • inhaled by (uninfected individual)
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14
Q

Suggest reasons why incidence of TB is higher in low income groups

A
  • overcrowded (living space)
  • poorly ventilated (living space)
  • poor diet/ malnourished
  • poor health
  • homelessness
  • more likely to consume, meat/milk from infected cattle
  • vaccination/medical treatment, more difficult to access
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15
Q

State features of malarial parasite that indicate that it is not a prokaryote

A
  • Nuclues/ nuclei
  • membrane bound organelles
  • large ribosomes
  • no cell wall
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16
Q

Describe how mosquitos transmits malarial parasite to a human

A
  • (mosquito) is a vector
  • Plasmodium/ parasite, present in (mosquito), saliva/ salivary gland
  • infected mosquito, feeds on/bites, human
  • Plasmodium/parasite passed (from saliva) to blood
17
Q

Suggest reasons why people may be concerned about using insecticides

A
  • Development of insecticide resistance
  • might cause unintended health problems in humans
  • might harm other/unintended species
  • bioaccumulation/biomagnification
18
Q

Suggest how the effects of insecticide use on a population of mosquitos could be measured and state the steps that should be taken in order to produce valid and reliable results

A

FIELD INVESTIGATION:

  • (sampling) before and after insecticide treatment
  • unbiased/ random, sampling of population
  • example of sampling technique; sweep net, pond net, light trap
  • (sampling in different, times/ weather
  • large number of samples taken
  • standardised sampling procedures
  • preventing counting same individual more than once
  • capture-recapture
  • calculate mean/ calculate standard deviation/ apply statistical test

LABORATORY INVESTIGATION

  • with and without insect exposure
  • measuring mosquito survival/ count surviving mosquitos
  • controlling one named key variable; exposure time/species of mosquito/stage of mosquito life cycle/ sex of mosquito/ insecticide type
  • using a range of insecticide concentrations
  • replicates
  • calculate mean/ standard deviation/ apply statistical test
19
Q
A
  • T
  • T
  • B
  • both
  • T
20
Q

Describe the changes in antibody concentration that occur in the patients blood during the primary response

A
  • no antibodies detected before 4 days/antibodies appear at 4 days
  • increase then decrease
  • figures
  • decrease = less steep than increase
  • antibody concentration returns to zero at 27 days
21
Q

Function of the hinge region of an antibody

A
  • flexibility/ binding of more than one antigen
22
Q

Function of the constant region on an antibody

A
  • attachment/ binding to phagocytes
23
Q

Function of the variable region on an antibody

A
  • binding/ attachment to antigens
24
Q

State two differences between primary and secondary immune response

A
  • secondary response, starts earlier/ has shorter delay before resonse
  • secondary response, more rapid/ faster
  • secondary response, higher/produces more antibodies
25
Q

Neuraminidase is an enzyme which is present on the protein coat of the influenza virus
This enzyme is used to break down the host cell membrane and allow the influenza viruses to leave the infected cell. Tamiflu is a neuraminidase inhibitor

Suggest how Tamiflu could inhibit neuraminidase

A
  • Tamiflu is, competitive/ non-competitive inhibitor
  • fits or binds to active site/complementary shape to active site/competes for the active site
    or fits into allosteric site or site other than active site/ changes shape of active site
  • prevents substrate binding to active site/ formation of ESC
26
Q

Suggest why researchers may concentrate their research on finding a new drug on plants that have been used in traditional medicine?

A
  • (plants) already identified as likely to have, medicinal properties/ few side effects
  • reduces, time/ effort, in finding, plants/ active chemicals/ (possibly) reduces cost
27
Q
A