extended response question unit 2 Flashcards
1
Q
benefits of asexual reproduction
A
- successful genome passed on
- in narrow stable niches
- when recolonising disturbed
habitats - vegetative cloning in plants
- parthenogenesis
- (parthenogenesis) where
parasite burden is low
2
Q
costs and benefits of sexual reproduction
A
- males are unable to
produce offspring - only half of (each parent’s)
genome passed on (to
offspring) - disrupts successful (parental)
genomes - increases (genetic) variation
- (variation) allows adaptation
3
Q
difficulties involved in treatment and control
A
- endoparasite defined as living within host
- rapid antigen change/high
antigenic variation - vaccines difficult to design/
produce - (some) parasites difficult to
culture (in vitro/laboratory) - similarity between host and parasite metabolism
- difficult to find drugs only
toxic to parasite - difficulty associated with
vector control - transmission rate high in
tropical climate/
overcrowded situations - overcrowding (can occur) in refugee camps/rapidly
growing cities (in LEDCs) - difficult/expensive to improve sanitation
4
Q
realised and fundamental niche
A
- niche
- fundamental niche
- realised niche
- competitive exclusion
- resource partitioning
5
Q
features of parasite niches
A
- parasite gain
- narrow niche and host specificity
- parasites can be degenerate
- ectoparasites
- endoparasites
- definitive host
- intermediate host
- vector
6
Q
meiosi ll
A
- chromosomes line up singly
- chromosomes separate
- randomly distributed
to the daughter cells - four haploid gametes formed
6
Q
specific cellular responses
A
- White blood cells release
cytokines if tissue damaged/
infected
b. Specific wbc accumulate at site
of damage/infection
c. Lymphocytes have receptors that recognise
antigens
d. Binding of antigen to receptor/
lymphocyte selects the
lymphocyte to divide
e. And produce a clonal population
f. Some lymphocytes induce
apoptosis AND others produce antibodies
g. Variable region of antibody binds to antigen
7
Q
the activity of homologous chromosomes
A
- homologous chromosomes
- pairing
- chiasmata
- crossing over occurs
- exchange of DNA between chromosomes
- new combinations of alleles
- chromosomes line up randomly
- independent assortment
- separation of parental chromosomes
8
Q
natural selection
A
- non random
- acts on genetic variation
- mutations
- new sequences of DNA
8
Q
courtship and female choice
A
- honest signals
- sexual dimorphism
- lekking
9
Q
genetic drift
A
- important in small populations
- population bottlenecks
- founder effects
- alleles under represented
