PLANT GROWTH LAB - Fog.ccsf.edu

PLANT GROWTH LAB
I. Root Formation and Auxin
• Follow procedure in lab, be sure to label your pots with your group name
• Use Coleus plant stems (1-2” from tip to base) in beaker on your tray.
J. Effect of Auxin on Stem
• Use small potted Coleus plants on your tray
• Be sure to label pots with your group name
K. & J Effect of Gibberellin on Stems
• In this part of the lab you will investigate the effect of gibberellins on plant growth
for 2 different types of phenotypes: dwarf bean seedlings and normal bean seedlings
(instead of corn). The dwarf seedlings are produced by a genetic mutation leading
to a lack of gibberellins.
• You will use these 2 types of plants to examine the effects of gibberellins on plant
growth.
• Pick 1 or 2 plants to make markings that are 1 mm. apart on the stem. You will use
this to check growth rate (“L”). You may want to do this on a normal and dwarf
plant.
• Place plants in tray either labeled “Gibberellin” or “Water”
Procedure:
1) Obtain 2 normal plants (in green pots) and 2 dwarf plants (in clay pots).
2) Label the pots as follows:
i) Pot 1: normal pea, water , your initials
ii) Pot 2: normal pea, gibberellin, your initials
iii) Pot 3: dwarf pea, water, your initials
iv) Pot 4: dwarf pea, gibberellin, your initials
3) Measure & record the length of each plant, from soil to shoot tip. Because the plants
are delicate, it helps to run a piece of string along the length of the stem and measure
the string, instead of forcing the stem along the straight ruler and potentially
damaging the plant.
4) Apply the appropriate treatment to each plant—either distilled water (pots 1 & 3) or
distilled water with gibberellin (pots 2 & 4). It is important to be consistent in
application, so that the only variable is gibberellin, not amount of water applied to
each plant. So for example, each plant should be sprayed 3 times with the appropriate
treatment every day (spray over the sink). Please be careful to not accidently spray
the wrong treatment on the wrong plant. Also, water your plants (the soil).
5) The class will be broken into 6 table groups so that you will have 6 replicates for this
experiment. Next week, we will re-measure each plant, calculate the change in height
for each plant treatment for each group and then share this data with the rest of the
class. Each person will then take this data and write it up in a lab report.
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6) For lab report:
i) Include all of the components of a lab report (introduction, methods, results,
discussion, and references). You will want to consider how to present the data
(e.g. tables, bar graphs…) and how to analyze it (e.g. compare mean
difference in growth between treatments, controls…..).
ii) Lab report due for each person: see schedule
M. Terminal Bud Effect on Growth
• Will make demo for whole class to observe.
N. Phototropism—skip
O. Gravitropism
• Observe example demonstration
P. Etiolation
• Observe example demonstration
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