Flashcards in Module 4 Deck (57)
What are the 5 kingdoms?
Prokaryotae, protoctista, fungi, Animalia, plantae
General features of prokaryote
unicellular, no nucleus or membrane bound organelles
(e.g. bacteria such as E.coli)
General features of protoctista
mainly unicellular, nucleus and membrane organelles, some have chloroplasts
General features of fungi
uni/multicellular, nucleus and other membrane bound organelles, cell wall of chitin, saprophytic feeders
General features of plantae
multicellular, nucleus and other membrane bound organelles, contain chlorophyll, autotrophic feeders
General features of Animalia
multicellular, nucleus and other membrane bound organelles, heterotrophic feeders
What are the 3 domains
Eukarya (80s ribosomes)
Archaea (70s ribosomes)
Bacteria (70 ribosomes)
What is prokaryotae split into in the six-kingdom system
Archaebacteria (ancient bacteria that live in extreme environments)
Eubacteria (bacteria found in all environments)
What evidence is there for evolution?
Palaeontology, Comparative anatomy and comparative biochemistry.
How is palaeontology evidence for evolution?
Complex fossils found in recent rocks
Sequence in which organisms are found match their ecological links
Studying anatomy can show how closely related organisms are
How is comparative anatomy evidence for evolution?
Homologous structures (structures that appear superficially different but have the same underlying structure) provide evidence for divergent evolution (closely related species diversify to adapt to new habitats)
How is comparative biochemistry evidence for evolution
Similarities and differences in cytochrome c and ribosomal RNA
What are genetic causes of variation?
Genes have different alleles
Meiosis (crossing over and independent assortment)
What are environmental causes of variation?
Sunlight, food, shelter, scars
What are environmental and genetic causes for variation?
Height= parents may be tall but diet also affects growth
Skin colour=genetics and how much melatonin skin contains
What are anatomical adaptations?
What are behavioural adaptations?
the way an organism acts
What are physiological adaptations?
processes that take place inside an organism
What do analogous structures provide evidence for?
Convergent evolution (unrelated species begin to share similar traits)
Analogous structures=species have adapted to perform the same function but different genetic origin
What is species richness?
the number of different species living in a particular area
What is species evenness?
a comparison of the number of individuals of each species living in a community
What is opportunistic sampling?
Uses organisms that are conveniently available
What is stratified sampling?
populations divide into strata based on a particular characteristic (e.g..male and female)
What is systematic sampling?
different areas within a habitat are identified, which are sampled seperately.
Why is sampling never entirely representative?
Sampling bias and chance
Factors that increase genetic biodiversity
Gene flow (interbreeding between different populations)
Factors that decrease genetic biodiversity
Selective breeding (artificial selection)
Genetic bottlenecks (a few individuals within a population survive event/change)
The founder effect (where a small number of individuals geographically isolate themselves)
Genetic drift (when a particular all disappears from a population)
How can human interfere with biodiversity?
Deforestation, agriculture, climate change
Aesthetic reasons for maintaining biodiversity
Presence of plants and animals, inspiration for writer and musicians, reduce stress
Economic reasons for maintaining biodiversity
Soil erosion and desertification can reduce crop growth, species with potential economic importance may become extinct (medicinal and chemical uses) ecotourism,
Ecological reasons for maintaining biodiversity
Disrupt food chains, when a keystone species is removed the habitat is drastically changed
What is the IUCN?
Publishes the red list, detailing threatened animals
What is CITES?
Regulates international trade
What is the Rio Convention?
What is the Countryside stewardship scheme?
Sustains the beauty and diversity of the landscape, improves biodiversity
What is ring rot?
A bacterial disease in potatoes and tomatoes. No cure
What is tobacco mosaic virus?
A virus that infects tobacco plants. No cure
What is potato blight?
Caused by a fungus-like protoctista. The hyphae penetrate host cells. No cure
What is black Sigatoka?
A diseased caused by fungi that affect bananas. Fungicide can control the spread but no cure
What is TB?
A bacterial disease that destroys lung tissue and suppresses the immune system. Curable
What is bacterial meningitis?
A bacterial infection of the brain. Curable
What is HIV/AIDS?
Caused by a virus suppressing the immune system. Transmitted by bodily fluids
What is influenza?
Viral infection of the ciliated epithelial cells in the gaseous exchange system.
Physical plant defences
Callose deposited between cell walls and cell membrane, sieve plates in the phloem and in the plasmodesmata
Chemical plant defences
Insect repellant (citronella)
Antibacterial compounds (phenols)
Antifungal compounds (chitinases)
General toxins (cyanide)
Non specific animal defences to keep pathogens out
Skin, mucous membranes, lysozyme in tears and urine
-thromboplastin results in the formation of a blood clot
-serotonin makes smooth muscle in blood vessels contact, reducing blood supply
-histamines raise the temp preventing pathogens reproducing and make blood vessels more leaky so blood plasma is forced out, tissue fluid causes swelling
-cytokines attract phagocytes for phagocytosis
Non specific animal defences to get rid of pathogens
Phagosome-phagolysosome-enzymes digest and destroy pathogen-MHC forms-MHC moves pathogen antigens to the surface membrane- forms APC
Cytokines- cell signalling molecules, informing other phagocytes that the body is under attack
Opsonins-tag pathogens so they can easily be recognised by phagocytes
How do antibodies defend the body?
Act as agglutinins causing pathogens to clump together, easier for phagocytes to engulf
Act as anti-toxin, binding to toxins produced by pathogens making them harmless
What do T helper cells do?
produce interleukins stimulating B cells, which increase antibody production
What do T killer cells do?
produce perforin which kill pathogens
What do T memory cells do?
have an immunological memory
What do T regulator cells do?
suppress the immune system, preventing an autoimmune response
What do plasma cells do?
What do B effector cells do?
divide to form plasma cell clones
What do B memory cells do?
have an immunological memory
What is cell mediated immunity?
When cells change (cancer)
Macrophages engulf and digest phagocytes forming an APC
Complementary T helper cells produce interleukins which stimulate more B and T cells to divide