weeks 1-3 Flashcards
6 types of asexual reproduction
fission (a parent organism, splitting into equal parts), budding (a parent organism divides itself into 2 unequal parts), fragmentation (framents of an organism break off and then become a new organism eg. in a sea star), vegetative propagation (where a new plant grows from a fragment of the parent plant), spore formation and parthenogenesis (an unfertilised egg develops into an individual, and is ‘fertilised’ by a polar body)
which kingdoms of life are asexual reproduction found in
all of them
which kingdoms of life are sexual reproduction found in
protista, fungi, plantae and Animalia (eukaryotic)
4 ways in which sexual reproduction varies
dioecious vs monoecious/hermaphrodites (whether an individual has only one sexual organ or both), internal vs external fertilisation, oviparous (egg laying) vs viviparous (embryo develops), few offspring vs many offspring
what are the male and female sexual organs of an angiosperm
stamen (male) and carpel (female)
why is fermentation not considered respiration
does not use the electron transport chain
what are hyphae
small branching fillamental structures that absorb oxygen from tiny air spaces between soil particles on fungi
what are pneumatophores
arial roots (above ground), found in low oxygen, waterlogged environments
what are aerenchyma
small air pockets that allow for the exchange of gases from exposed, to submerged parts of a plant
what are the 5 types of gas exchange systems in animals
direct diffusion (small animals will do that), integumentary exchange (similar to diffusion except there will be some sort of circulatory system to transport the gas once it is in the body), trachea (found in insects, small tubular structures that branch through the body), gills and lungs
what is the evolution of jawed fish linked to
the decline of marine invertebrates - they had a competitive advantage
what are flame cells
specialised excertory cells found in freshwater invertebrates - act like a kidney and remove waste materials
what is a bundle of flame cells called
protonephridia
what is the coelom
a fluid filled cavity surrounding the gut
roles of the coelem
internal support (because it is fluid filled), allows for the evolution of more specialised organs, transport of fluid, enables (and correlates with) increased body size
what is guttation
where drops of xylem sap gather at the tips or edges of leaves of some plants, as a method of waste removal
advantages of passive movement
little or no energy expenditure
disadvantages of passive movement
little or no control of where the organism goes, possible to move to a suboptimal environment
advantages of living in water
hydration, nutrient rich (and easy to access) and environmentally buffered (no extreme temp changes)
challenges of living in water
motion is hard because of strong currents and buoyancy
challenges of living on land
oxygen is gaseous (needs to be dissolved to be captured), dehydration, UV radiation, passive movement is limited, terrestrial ecosystems are complex to navigate
challenges of living in the air
have to resist gravity, strong wing currents, extremely energy hungry
what are psuedopods
meaning false feet, how unicellular amoebae move by altering their shape by pushing cytoplasm outwards
what are molluscs and how do they move
including squid, octopus, cuttlefish, slugs and snails. they take in water through their moth and then contract their body to push the water through their funnel
adaptions that allow for flying include:
less dense bones, enlarged chest muscles for flight, feathers, systems of air sacs in the body that allow them to extract much more oxygen per breathe
what did a more erect upright stance allow for
longer legs and faster movement
what is the anthropocene
the current period we are in, describing the period where the world has been impacted by human activity - our extinction rates are nearing those seen in mass extinctions
does natural selection act on the population or the individual
the population
what are the 5 driving forces of evolution
natural selection, mutation, sexual reproduction, genetic drift and gene flow
define species
a group of (potentially) interbreeding individuals that are reproductively isolated from other such groups
What is Ne
the effective population size - the number of individuals that contribute to the next generation (the size of a population that would have the same effect of random sampling gene frequency as the actual population)
what are the conditions of hardy weinburg equilibrium and what does it mean
it serves as the null hypothesis for evolution - genotype frequencies will not change between generations (dominant genotypes will not override reccessive). conditions are no migration, no mutation, equal fitness (no selection) and infinite population size (small populations are impacted by chance events) and mating is random
equation for hardy weinburg equilibrium
p2 + 2pq + q2 = 1
what are the 3 types of selection
directional (positive) selection - favours one end of the distribution of phenotypes, stabilising selection - favours individuals in the middle of the distribution of phenotypes. Disruptive selection - favours individuals on either end of the distribution
example of heterozygote advantage
sickle cells and malaria - a heterozygote is resistant to malaria
what is relative fitness
describes the success of a genotype at producing new individuals, standardised by the success of other genotypes on a scale of 0-1
