L3
讲座
1. What is the lecture mainly about?
Hypotheses about the rate at which vines grow around their hosts
Reasons that only some vines twist around their hosts
Possible explanations for the way vines twist around their hosts
Molecular differences between vine species in the Northern and Southern Hemispheres
2. Why does the professor mention houseplants growing in the direction of the Sun?
To explain why researchers doubt that the direction in which vines twist is random
To help explain the tracking hypothesis
To explain the contrast between the way indoor and outdoor plants grow
To correct a common misconception about the Sun’s role in plant growth
3. What was the professor’s original opinion regarding the tracking hypothesis?
It was the most likely explanation of why vines twist in certain directions.
It was too simplistic an explanation.
Previous studies had already suggested its plausibility
Certain details about the way vines climb hosts were not taken into consideration.
4. What premise do the Coriolis effect hypothesis and the tracking hypothesis have in common?
The direction in which vines grow is affected by the rotation of Earth.
The direction in which vines grow is determined by the movement of the Sun across the sky
The direction in which vines grow depends on the species of the host tree.
The direction in which vines grow depends on which hemisphere they are in.
5. Why were the three original hypotheses about the direction in which vines grow rejected?
Vines in the Southern Hemisphere did not twist in the direction ecologists had predicted.
Most of the vines examined twisted in the same direction.
Twisting direction was found to be determined by the vine species.
It was discovered that the direction in which a vine twists is completely random.
6. According to the professor, what is the new hypothesis that ecologists are testing?
Only right-handed amino acids are present in vines growing in the Southern Hemisphere.
The direction in which vines twist permanently alters their molecular structure.
Twisting direction is determined at the molecular level of vines.
Outside organisms can influence the way vines grow.
