mistakes Flashcards
adaptations of phloem (sieve tube)
- sieve plate with sieve pores - allows for continuous movement
- cellulose cell wall - strengthens wall to withstand hydrostatic pressure
- no nucleus, vacuole or ribosome - maximise space for translocation
- thin cytoplasm - reduces friction to facilitate movement
adaptations of phloem (companion cells)
- nucleus and other organelles present - provides metabolic and genetic support to sieve tube elements, helping w loading and unloading
- transport proteins in plasma membrane - moves assimilates into and out of sieve tube elements
- large numbers of mitochondria (provide ATP for active transport)
- plasmodesmata - allows organic compounds to move from companion cells to sieve tube elements
explain what the Rf values represent in chromatography
equation
- depends on relative solubility of the pigment
- each pigment has a specific Rf value
- can be used to identify different pigments
give 3 examples of photosynthetic pigments
chlorophyll, carotene, xanthophyll
compare and contrast exchange of energy with nutrient cycling in ecosystems
both
- flow through ecosystems
- both used for metabolism and growth
energy:
- source is the sun
- lost as heat between each trophic level
- is not recycled
nutrients
- source is soil/rocks
- escape food chains as litter/feces
- recycled
causes of eutrophication
- excess nutrients in an aquatic system
- natural runoff from soil/erosion/weathering of rocks
- runoff of fertilisers
- partially treated sewage
explain what information a pyramid of energy provides about an ecological community
shows the amount of energy at each trophic level measured over a given period of time. The units are energy per area per time. The width/size of each bar represents the amount of energy the bottom level represent the producers, and subsequent levels represent consumers. Each level should be roughly one tenth of the size/10 % of the preceding
level as the energy that enters a community is ultimately lost as heat/in
respiration.
explain why viral diseases cannot be treated using antibiotics
- viruses are not living
- viruses lack metabolism
- antibiotics target metabolic pathways
describe the origin of eukaryotic cells according to the endosymbiotic theory
a. mitochondria and chloroplasts are similar to prokaryotes ✔
b. host cell took in another cell by endocytosis/by engulfing in a vesicle ✔ Allow “taking in” in place of “engulfing”
c. but did not digest the cell/kept the ingested cell alive, developing a symbiotic/mutualistic relationship between engulfed and host cell ✔
d. chloroplasts and mitochondria were once independent/free-living organisms ✔
e. DNA loop in chloroplast/mitochondrion
g. double membrane around chloroplast/mitochondrion ✔
h. 70s ribosomes in chloroplast/mitochondrion ✔
explain how insects secrete nitrogenous waste
a. excreted as uric acid ✔
b. excretion by Malpighian tubules ✔
c. nitrogenous waste/ammonia «accumulates» in hemolymph ✔
d. nitrogenous waste/ammonia absorbed by Malpighian tubules ✔
e. ammonia converted to uric acid ✔
f. conversion to uric acid requires energy/ATP ✔
g. high solute concentration in Malpighian tubules due to active transport of ions/Na+/K+ into Malpighian tubules ✔
h. water absorbed by osmosis flushes uric acid/nitrogenous waste to «hind» gut ✔
i. water/ions reabsorbed from the feces and returned to hemolymph ✔
j. uric acid precipitates/becomes solid/forms a paste so can pass out with little water ✔
k. uric acid excreted/egested with the feces ✔
l. water conservation/osmoregulation
m. uric acid is non-toxic ✔
draw labelled diagrams to show a condensation reaction between two amino acids
outline a reason in which reef building corals are affected by increasing atmospheric carbon dioxide
- corals have exoskeletons made of calcium carbonate
- CaCO3 shells dissolve in acidic conditions
- high co2/acidic conditions reduce availability of CaCO3 for forming shells
explain how aphid stylets can be used to study the movement of solutes in plant tissues
a. aphids tap into phloem with their stylets «to use sap as a food source»
b. plants grown in radioactive CO2/14CO2 incorporate it into carbohydrate
c. phloem contents/sap/fluid flows through the stylet
d. aphid body severed/cut from stylet «after stylet inserted into phloem»
e. analyze «sap/fluid exuded from stylet» for solutes/carbohydrates
OR
radioactive-labelled carbon can be detected «in the phloem sap»
f. stylets at different parts of the plant can show sequence/rate of movement
explain the effects of auxin on plant cells
a. increases cell elongation/growth/enlargement OR has effect on rate of mitosis
b. changes the pattern of gene expression
promotes transcription of some genes
c. changes the pH of the extracellular environment/cell wall and
increases activity of proton pumps
d. breaks cross links/connections between cellulose fibres in cell wall
e. increases cell wall plasticity
f. «varying» auxin concentrations have different effects in different parts of
the plant
explain changes in biomass for the biomass-respiration graph
a. increases cell elongation/growth/enlargement OR has effect on rate of mitosis
b. changes the pattern of gene expression
OR
promotes transcription of some genes
c. changes the pH of the extracellular environment/cell wall
OR
increases activity of proton pumps
d. breaks cross links/connections between cellulose fibres in cell wall
e. increases cell wall plasticity
f. «varying» auxin concentrations have different effects in different parts of
the plant
explain why biomass continues to increase after the respiration levels plateau
a. development of mature trees requires xylem/wood
b. xylem/wood contributes to biomass but not respiration
c. photosynthesis/production greater than respiration
d. photosynthesis/production continues to accumulate biomass
OR
accumulated biomass remains/increases
what do ocean currents do to plastic debris
they concentrate them
outline the requirements for sustainability within a sealed mesocosm
- photosynthetic organisms/autotrophs/plants as producers;
- light (as energy source) for photosynthesis;
- nutrient/water recycling (by saprotrophs);
- decomposers/saprotrophs to breakdown (toxic) wastes;
outline primary succession
colonization of areas that were barren/not previously inhabited/not occupied by organisms;
outline processes that must occur over time to produce deeper soil
- weathering of rock accumulates matter (allowing pioneer species to grow);
- death/decomposition of organisms increase organic matter/detritus/litter;
- increased soil allows larger/more plants to grow / roots preventing erosion;
- as more plants are decomposed, soil depth/amount of soil available increases;
explain how levels of PCBs increase so greatly over trophic levels
- as producers/algae take in nutrients, they also collect/absorb PCBs;
- consumers can take in PCBs directly from the water;
- PCBs are not digested/metabolized;
- PCBs build up in cells/tissues / bioaccumulate;
- PCBs pass on to higher level consumers or
organisms in the higher trophic levels accumulate more; - At each trophic level there is biomagnification;
explain how biogeographic factors affect the richness and evenness of biodiversity
- biogeographic features are combinations of species, habitats and physical features
- richness is the number of different species present (in an area)
- evenness refers to relative abundance of the different species (in an area)
- large nature reserves/large islands have greater biodiversity
- large areas have more species/populations/habitats/richness
- connected areas/nature reserves have more diversity than isolated ones/corridors between areas increases biodiversity
- the greater the surface:perimeter ratio, the greater the biodiversity
- edges are transition areas
- circular shape has more biodiversity than rectangular shape;
- biodiversity measured by Simpson’s / diversity index;
Suggest changes in the management of a national park that could reduce the amount
of macroplastic pollution.
- recycling programs
- place litter containers/garbage cans close to camping sites
- fines for those causing pollution or pass littering laws
Describe one method that could have been used to estimate the population size of a
given tree in a forest after fire damage had occurred.
- random sampling using quadrats
- trees counted in quadrant
- population calculated using area
