Q5b-Plant Responses Flashcards
Phototropism is when…
A plant grows in such away that it bends toward a light source
A vine’s tendrils contact a chain-link fence and the wrap around the wires this is…
Thigmotropism
Daily patterns of metabolism, nyctinastic movements of leaves & flowers, and hormone production are all driven by a plants…
Circadian rhythms
A plant species that flowers in the Fall as night gets longer is probably a…
Short day plant
Poinsettias are short-day plant. Why would growing them (in the Fall in preparation for Christmas) in a greenhouse near where trucks come in at night to unload be a bad idea?
Night time light from headlights of the parked trucks through the greenhouse glass will convert Pr (Photochrome) to the Pfr form and thus inhibits flowering.
How do plants detect night-day lengths?
with the photoreceptor phytochrome
Tulip buds grow well in their first season in east Texas gardens but perform very poorly in the next Spring if left in the ground. However, if they are removed and put in the ‘fridge for 12-16 weeks in the Fall/Winter and replanted they will grow well in the spring. Why is that?
The soil doesn’t get cold enough in our mild winters; bulbs that overwinter here haven’t had proper stratification
When flowers or leaves orient themselves with the sun throughout the day is called…
Heliotropism
What is an example of thigmonasty?
A Venus fly trap slamming shut when a fly touches its ‘trigger hairs’
What happens if you touch the leaves of the local Mimosa(powder puff flower) species sensitive briars?
the leaflets fold up
