Exam 39: Plant Responses to Internal and External Signals

Plant hormonal regulation differs from animal hormonal regulation in that ________.

If you were shipping green bananas to a supermarket thousands of miles away, which of the following chemicals would you want to eliminate from the plants' environment?

Most scientists agree that global warming is underway; thus, it is important to know how plants respond to heat stress. Which of the following would be a useful line of inquiry to try and improve plant response and survival to heat stress?

The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve ________.

________ prevents seeds from germinating until conditions are favourable for the growth of the plant.

A plant scientist was hired by a greenhouse operator to devise a way to force iris plants to bloom in the short days of winter. Iris normally blooms as a long-day (short-night) plant. Which of the following has the best chance of creating iris blooms in winter?

Plants often use changes in day length (photoperiod) to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes ________.

In extremely cold regions, woody species may survive freezing temperatures by ________.

Experiments on the positive phototropic response of plants indicate that ________.

Plant hormones ________.

Which event during the evolution of land plants favoured the synthesis of secondary compounds?

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only ½ centimetre of soil is that the ________.

In the autumn, the leaves of some trees change colour. This happens because chlorophyll breaks down and the accessory pigments become visible. What hormone is responsible for this?

Suppose you laid a seedling on its side so that the root was parallel to the ground as shown in the figure. Several hours after the change in position, where in the root cells, position A, B, or C in the figure, would you find the amyloplasts?

Apical dominance in plants is under the control of ________.

A gardener in Canada wants to surprise his mother on her birthday and make her favourite hibiscus bush flower in May instead of at the end of June. The bush is growing in the greenhouse. Which of the following might make the hibiscus bush flower early?

The detector of light during de-etiolation (greening) of a tomato plant is (are) ________.

Auxin enhances cell elongation in all of these ways except

You have a small tree in your yard that is the height that you want it, but does not have as many branches as you want. How can you prune it to trigger it to increase the number of branches?

Which type of mutant would be most likely to produce a bushier phenotype?