Exam 39: Plant Responses to Internal and External Signals

Which of the following can function in signal transduction in plants? I.calcium ions II.nonrandom mutations III.receptor proteins IV.autochrome V.secondary messengers

Charles and Francis Darwin discovered that

You may have observed plants rotate towards a light source, thereby increasing the plant's ability to intercept light energy and increase photosynthesis. You, however, are given the task of preventing grass seedlings from rotating toward the light. Using your knowledge of phototropism, which of the following experimental procedures would you use to complete your task?

Use the figure to answer the following question. 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?

Which of the following statements best summarizes the acid growth hypothesis in an actively growing shoot?

Which one of the following hormones regulates cell division in plants?

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?

A population of plants experiences several years of severe drought. Much of the population dies due to lack of water, but a few individuals survive. You set out to discover the physiological basis for their adaptation to such an extreme environmental change. You hypothesize that the survivors have the ability to synthesize higher levels of ________ than their siblings do.

Upon exposure to blue light, plants not only begin to grow toward the light, but move their chloroplasts to the sunny side of each cell. The adaptive advantage of moving chloroplasts to the sunny side of each cell ________.

Plant hormones ________.

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

If a farmer wanted more loosely packed clusters of grapes, he would most likely spray the immature bunches with ________.

When an arborist prunes a limb off a valuable tree, he or she may paint the cut surface. The primary purpose of the paint is to ________.

Which of the following mechanisms is in the correct sequence of steps (I-IV as listed below) that takes place during the formation of de-etiolation (greening) response proteins in plants? I.Detection of light signal II.Activation of phytochrome III.Activation of specific protein kinase1 IV.Formation of de-etiolation response protein

Which of the following environmental factors can be sensed by plants? I.gravity II.pathogens III.wind IV.light

The biological clock controlling circadian rhythms must ultimately ________.

Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only 1/4 inch of soil is that the ________.

Which one of the following hormones stimulates stem elongation and pollen tube growth?

A gardener in Canada wants to surprise his mother on her birthday and make her favorite 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?

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