Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Advanced Higher Biology > Unit 2 - Parasitism > Flashcards

Unit 2 - Parasitism Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is a ecological niche?

A

An ecological niche is a multi-dimensional
summary of tolerances and requirements of a
species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a fundamental niche?

A

A species has a fundamental niche that it
occupies in the absence of any interspecific
competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a realised niche?

A

A realised niche is occupied in response to
interspecific competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is competitive exclusion?

A

where the niches of two species are so similar that one declines to local extinction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is resource partitioning?

A

Where the realised niches are sufficiently
different, potential competitors can co-exist
by resource partitioning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is paratitism?

A

Parasitism is a symbiotic interaction between
a parasite and its host (+/-). A parasite gains benefit in terms of nutrients
at the expense of its host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference in the reproductive potential of the host to parasitise?

A

Unlike in a predator–prey relationship, the
reproductive potential of the parasite is
greater than that of the host.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do parasites have?

A

a narrow (specialised)
niche as they are very host-specific

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does degenerate mean?

A

lacking structures and organs found in other organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the host provide?

A

As the host provides so many of the
parasite’s needs, many parasites are
degenerate, lacking structures and organs
found in other organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an ectoparasite?

A

An ectoparasite lives on the surface of its
host,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an endoparasite?

A

lives within the tissues of its host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the definitive host?

A

The definitive host is the organism on or in
which the parasite reaches sexual maturity.
Intermediate hosts may also be required for
the parasite to complete its life cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a vector?

A

A vector plays an active role in the
transmission of the parasite and may also be
a host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the life cycle of Plasmodium?

A
  • An infected mosquito, acting as a vector,
    bites a human.
  • Plasmodium enters the human bloodstream.
  • Asexual reproduction occurs in the liver and then in the red blood cells.
  • When the red blood cells burst gametocytes are released into the bloodstream.
  • Another mosquito bites an infected human and the gametocytes enter the mosquito, maturing into male and female gametes, allowing sexual reproduction to now occur.
  • The mosquito can then infect another human host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the life cycle of Schistosomes?

A
  • Schistosomes reproduce sexually in the human intestine.
  • The fertilised eggs pass out via faeces into water where they develop into larvae.
  • The larvae then infect water snails, where asexual reproduction occurs.
  • This produces another type of motile larvae, which escape the snail and penetrate the skin of a human, entering the bloodstream.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the definitive host in plasmodium?

A

In the mosquito

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the intermediate host in plasmodium?

A

Human where asexual reproduction takes place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the definitive host of the schistosomes?

A

Human

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the intermediate host of the schistosomes?

A

Snail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are viruses?

A

Viruses are parasites that can only replicate
inside a host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do viruses contain?

A

Viruses contain genetic material in the form
of DNA or RNA, packaged in a protective
protein coat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are viruses surrounded by?

A

Some viruses are surrounded by a
phospholipid membrane derived from host
cell materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the outer surface of a virus contain?

A

The outer surface of a virus contains
antigens that a host cell may or may not be
able to detect as foreign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the viral life cycle stages?

A
  • Infection of host cell with genetic material
  • host cell enzymes replicate viral genome
  • transcription of viral genes
  • translation of viral proteins
  • assembly and release of new viral particles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is RNA retroviruses?

A

RNA retroviruses use the enzyme reverse
transcriptase to form DNA, which is then
inserted into the genome of the host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What can viral genes do?

A

Viral genes can then be expressed to form
new viral particles

28
Q

What is transmission?

A

Transmission is the spread of a parasite to a
host

29
Q

What is virulence?

A

Virulence is the harm caused to a host
species by a parasite

30
Q

How are ectoparasites transmitted?

A

through direct contact

31
Q

How are endoparasites transmitted?

A

Endoparasites of the body tissues are often
transmitted by vectors or by consumption of
intermediate hosts

32
Q

What are the factors that increase transmission rates?

A
  • the overcrowding of hosts when they are
    at high density
  • mechanisms, such as vectors and
    waterborne dispersal stages, that allow
    the parasite to spread even if infected
    hosts are incapacitated
33
Q

Why are host behaviours exploited?

A

exploited and
modified by parasites to maximise
transmission

34
Q

What does the host behaviour become?

A

The host behaviour becomes part of the
extended phenotype of the parasite

35
Q

How are host behaviours altered?

A
  • host foraging
  • movement,
  • sexual behaviour
  • habitat choice
  • anti-predator behaviour.
36
Q

What can parasites do to supress the host immune system?

A
  • Modify host size
  • Modify reproductive rate (benefit the
    parasite growth, reproduction or transmission)
37
Q

What do defence against pathogens do humans have?

A

nonspecific and specific aspects

38
Q

What are the non-specific defences?

A

Physical barriers, chemical secretions,
inflammatory response, phagocytes, and
natural killer cells

39
Q

What are natural killer cells?

A

natural killer cells destroying cells infected
with viruses

40
Q

What does the epithelial tissue do?

A

Epithelial tissue blocks the entry of parasites;

41
Q

What do chemical secretions do?

A
  • hydrolytic enzymes in mucus, saliva and
    tears destroy bacterial cell walls;
  • low pH environments of the secretions of stomach,
    vagina and sweat glands denatures cellular
    proteins of pathogens.
42
Q

What happens when cells are injured?

A

Injured cells release signalling molecules. This results in enhanced blood flow to the site, bringing antimicrobial proteins and phagocytes.

43
Q

What is the process of phagocytosis?

A

Killing of parasites using powerful enzymes contained in lysosomes, by engulfing them and storing them inside a vacuole in the process of phagocytosis

44
Q

What do natural killer cells do?

A

Natural killer cells can identify and attach to
cells infected with viruses, releasing
chemicals that lead to cell death by inducing
apoptosis.

45
Q

What are the specific defences?

A

A range of white blood cells constantly
circulate, monitoring the tissues

46
Q

What happens if a tissue becomes damaged or invaded?

A

cells release cytokines that increase blood flow
resulting in non-specific and specific white
blood cells accumulating at the site of
infection or tissue damage

47
Q

What do different lymphocytes have?

A

each possessing a receptor on
its surface, which can potentially recognise a
parasite antigen

48
Q

What happens when an antigen binds to a lymphocytes receptor?

A

lymphocyte’s receptor selects that lymphocyte to then
divide and produce a clonal population of this
lymphocyte

49
Q

What are the two types of things lymphocytes can do?

A
  • Some selected lymphocytes will produce
    antibodies
  • others can induce apoptosis in parasite-infected cells
50
Q

What do antibodies possess?

A

regions where the amino acid sequence varies greatly between different antibodies

51
Q

What does the variable region do?

A

gives the antibody its
specificity for binding antigen

52
Q

What happens when an antigen binds to the binding site?

A

the antigen-antibody complex formed can
result in inactivation of the parasite, rendering
it susceptible to a phagocyte, or can
stimulate a response that results in cell lysis

53
Q

What do memory lymphocyte cells do?

A
  • can produce a secondary response when the
    same antigen enters the body in the future.
  • When this occurs antibody production is enhanced in terms of speed of production, concentration in blood and duration.
54
Q

What do endoparasites do to evade the immune system?

A
  • mimic host antigens to evade detection and modify host immune response to reduce their chances of destruction
  • It may also allow re-infection of the same host with the new variant
55
Q

How do some viruses escape immune surveillance?

A
  • by integrating their genome into host
    genomes,
  • existing in an inactive state known as latency.
  • The virus becomes active again when
    favourable conditions arise
56
Q

What is epidemiology?

A

Epidemiology is the study of the outbreak
and spread of infectious disease

57
Q

What is herd immunity threshold?

A

The herd immunity threshold is the density of
resistant hosts in the population required to
prevent an epidemic

58
Q

What do vaccines contain?

A

Vaccines contain antigens that will elicit an
immune response

59
Q

What makes it difficult to find drugs that only target the parasite?

A

The similarities between host and parasite
metabolism

60
Q

What must be reflected in vaccines?

A

Antigenic variation has to be reflected in the
design of vaccines

61
Q

Why is it often difficult to design vaccines?

A

Some parasites are difficult to culture in the
laboratory making it difficult to design
vaccines

62
Q

What are some of the challenges with parasites spreading?

A
  • overcrowding or tropical climates
  • Overcrowding can occur in refugee camps
    that result from war or natural disaster or
    rapidly growing cities in LEDCs.
63
Q

How do you reduce the rates of transmission?

A
  • Civil engineering projects to improve
    sanitation combined with co-ordinated vector
    control may often be the only practical control
    strategies
  • Improvements in parasite control reduce child
    mortality and result in population-wide
    improvements in child development and
    intelligence, as individuals have more
    resources for growth and development
64
Q

What happens when secondary exposure occurs?

A

When this occurs antibody production is enhanced in terms of speed of production, concentration in blood and duration

65
Q

How are memory cells formed?

A

Initial antigen exposure produces memory
lymphocyte cells specific for that antigen

Advanced Higher Biology (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions