Exam 39: Plant Responses to Internal and External Signals

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.

In order for a plant to initiate chemical responses to herbivory

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

Which of the following hormones would never be found in high concentrations in a dormant overwintering flower bud?

The houseplants in a windowless room with only fluorescent lights begin to grow tall and leggy.Which of the following treatments would promote more normal growth?

A plant will recognize a pathogenic invader

The following questions refer to the description below. Plants are not able to move away from predators,so they have evolved chemical methods to protect themselves.Biologists have observed that caterpillars munching on a leaf can be attacked by certain species of wasps.These wasps lay their eggs inside the caterpillar's body,and when the eggs hatch,the larvae feed on its host from the inside. -How do wasps find plants with caterpillars? You design an experiment in which one group of plants is torn/shredded by human fingers,another group of plants has leaves cut off with plant shears,a third group of plants has leaves stapled,and the fourth group of plants has leaves eaten by caterpillars.After several days of observation,only the plant with caterpillars has attracted wasps.The most likely conclusion is that

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

A long-day plant will flower

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

Which plant hormones would likely be found in high amounts in a sprouting vegetative stem?

Generalized defense responses in organs distant from the infection site are called

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

We know from the experiments of the past that plants bend toward light because

A short-day plant will flower only when

Why might animal hormones function differently than plant hormones?

Plant hormones produce their effects by I.altering the expression of genes. II.modifying the permeability of the plasma membrane. III.modifying the structure of the nuclear envelope membrane.

Auxin triggers the acidification of cell walls,which results in rapid growth,but also stimulates sustained,long-term cell elongation.What best explains how auxin brings about this dual growth response?

Which of the following is the most likely plant response to an attack by herbivores?

In lettuce seeds,blue light initiates germination.If you measured hormone levels within the seed,which hormone would be produced upon exposure to blue light?