Module 4 Flashcards
Describe ring rot, black sigatoka, ringworm, potato/tomato late blight. What pathogen are they caused by? What does this affect.
Ring rot - bacterium - potatoes, tomatoes
Black Sigatoka- fungal - banana plants
Ringworm - fungal - cattle
Potato/tomato late blight - protect its - potatoes/tomatoes.
Describe some defences that animals have against pathogens
Skin
Mucous membranes - protects body openings.
Blood clotting - mesh of protein fibres and platelets that can block wounds.
Inflammation - damaged tissue release chemicals that increase the permeability of blood vessels that leak fluid into the surrounding areas.
Wound repair - surface is repaired and new skin forms.
Explosive reflexes
What are some physical defences against pathogens in plants?
Waxy cuticle
Cell walls
Callose deposition at plasmodesmata (small channels in cell walls)
What are some chemical defences against pathogens in plants?
Saponins - destroy cell membranes in pathogens.
Phytoalexins - inhibit the growth of pathogens.
Describe the 4 stages of the immune response and what is involved in each.
- Phagocytes engulf pathogen:
- phagocyte recognises foreign antigen, this can be made easier by presence of opsnonins.
- pathogen is engulfed in a vesicle called a phagosome.
- lysosome fuses with the phagosome to form a phagolysosome.
- phagocyte presents the antigens and becomes an antigen presenting cell.
- neutrophils are the first to respond to pathogens, they are attracted to cytokines released at the site of the wound. - Phagocytes activate T lymphocytes
- receptors on the surface of T lymphocytes bind to the antigen presenting cells.
- the T lymphocyte is now activated, this is called clonal selection.
- it goes through clonal expansion and produces clones of itself.
- different types of activated t lymphocytes:
# t helper cells: they release substances to activate B lymphocytes and T killer cells.
# t killer cells: attach to and kill cells that are infected with a virus
# t regulatory cells: they suppress the immune response from other white blood cells just so that they don’t attack self-cells. - T lymphocytes activate B lymphocytes
- when B lymphocytes meet a complementary antigen it binds to it.
- once influenced by substances released by T helper cells, the B lymphocyte is activated.
- the B lymphocyte divides by mitosis into plasma cells and memory cells via clonal expansion - Plasma cells
- they are clones of B lymphocyte cells and secrete loads of the antibody.
Describe the mode of action of antibodies: 3 modes.
Agglutination
Neutralising toxins
Preventing the pathogens from binding to human cells.
Describe the 2 types of biodiversity
Species - group of similar organisms
Habitat - area inhabited by species
Describe the different levels of biodiversity
Habitat diversity - n.o. of different habitats in an area
Species diversity - n.o. of different species in an area
Genetic diversity - variation of alleles in a species.
What affects calculated biodiversity?
Species richness and species evenness
What is the Sampson’s index of diversity and what does the value represent
It doesn’t take genetic diversity into account. Formula: 1-(E(n/N)^2)
What is genetic polymorphism, how do we measure it.
Polymorphism describes a locus with two or more alleles. Proportion of polymorphic gene loci = n.o. of polymorphic gene loci/total n.o. of loci
Describe what affects global biodiversity
Human population growth
Increased use of monoculture
Climate change
What is conservation and what are some well known agreements of conservations like NGOs.
Conservation is important to ensure the survival of endangered species.
Rio Convention on Biological Diversity:
- aims to develop international strategies on the conservation of biodiversity and how to use organisms sustainably.
- provides guidance to governments on how to conserve biodiversity.
CITES agreement:
- increases international cooperation in regulating trade in wild animals
- it’s illegal to kill endangered species
- limits trade through licensing
- raises awareness
The countryside stewardship scheme
- paying landowners to follow management techniques
- 10,000 successful agreements in England.
What is the difference between classification and phylogeny
Classification is grouping together similar organisms via 8 taxonomic groups
Phylogeny tells us about the evolutionary history of organisms and helps us determine whether they were related or not.
Classification
- Do Domain
- Kings Kingdom
- Play Phylum
- Chess Classification
- On Order
- Fat Family
- Girls’ Genus
- Stomachs Species
What are the five kingdoms
Prokaryotes
Protoctista
Fungi
Plantae
Animalia
