Plant responses q' Flashcards
state an example of a response that plants use against herbivory
- production of pheromones
- folding in response to touch
- min period of darkness required for flowering is between 6.5 and 8.5 hrs
- cockleburs flower when day length /period of exposure to light decreases
- red light prevents flowering
- far red light reverses the effect of red light
- far red light reduces the period of darkness required for flowering
suuporting firms claim (F), against firms claim (A)
FOR
- as the vol of diatin increase the mass of seedless fruit harvested increases
A
- no scale on graph axes
- labels of graph axes are the wrong way round
- no errors bars
-should be %incr in mass
- correlation is not evidence of causation
- risk of bias
- zeatin is more productive than diatin
issues w/ validiity (v)
V
- no method given
-species is not named
- no CV given
- temp control no specfified
- conc of hormone not specified
- CO2 conc not specified
- location not specified (could be outside/greenhouse)
- soil type not specified
- water availability not specified
- light intensity not specified
- no control group to compare results
-no evidence of repeats
-no consideration of the interaction w/ other hormones /process
describe +explain the results shown in tables 3.1 + 3.2
describe : table 3.1
- light incr length+mass of both roots +stems
-group a has less growth than group B
table 3.2
- stem grows towards the light
- almost half the roots grow away from light
- some appear unaffected by light
explain: table 3.1
- more carbs produced during PS
- light may trigger growth +germination
table 3.2
- auxins produced in shoot tip moves to side away from light
- light allows PS
- positive phototropism in stems
- geotropism more important than phototropisms in roots
- could be measurement error
justify your choice of statistical test given
t test
comparing 2 means
- 8.1 is greater than 5.99 at 2 degress of freedom
- therefore significant difference at p=0.05
- not significant at p= 0.01
- indicates greater than 95% probabilty that diff is not due to chance
- null hypothesis can be rejected at p=0.05
state the name of a plant hormone that would be expected to affect root growth
Auxin
- amyloplasts are heavy
- binding of amyloplastst w/ ER release Ca2+
- Ca2+ stimulates growth
- the root grows to the side of the amyloplasts
shorter roots
- high auxin conc
taller
- gibberellins promote stem elongation by stimulating cell elongation +division
growth timing
- gibberellins promote seed germination by activating genes for amylase +protease enzymes , which break down food stores
side branches
- auxin maintains apical dominance +inhibits the growth of lateral shoots
delayed fruit + leaf fall
- a small addition of auxin slows down fruit drop and leaf fall
- auxin inhibits abscission by preventing ethenen production from increasing
state one hormone that promotes the ripening of fruit
ethene
what is the normal action of IAA in plant cells
stimulates cell elongation
- no proton pumping
- photophosphorylation stops
- less ATP produced
- less reduced NADP produced
- no calvin cycle
- no TP made
- no respiratory substrate
- results suggest action of plant hormone
- obervations suggest apical dominance
- which is mediated by auxin
- all plants will show spical dominance
explain why gibberelin is classed as a plant hormone
- is a chem messenger
- produced in one part of plant but has effects in another part
- affects activity of target tissues
- long-lasting
-wide spread effect
- seed germination
- transcription
- prevents leaf abscission
- aids stomatal opening
- promotes fruit development
- promotes activity of amaylase
L:1light intensity is not controlled
E1: diff light intensities could lead to variation in phototropism
I1:light intensity stays the same
L2: trial was not repeated
E2:cannot calc mean
I2: repeat at least twice
advantageous
- stops leaves being eaten
- so plant survives
- gene must be advantageous to be selected for
dis
- decreases reproductive success
- metabloic resources diverted to nicotine production
