Download 206 Questions

206 Questions
Exam 2, 2006
Possible Essay Questions
Describe the process and evolutionary advantage of de-etiolation in plants. Include in
your discussion the function of phytochrome, second messengers, and two possible
mechanisms of response. Also include the functions of some proteins and hormones
produced during de-etiolation.
Auxin plays many roles within a plant. One of it's chief functions is to stimulate cell
expansion. Describe it's journey from where it is synthesized to where it is perceived,
and the response.
Angiosperm species account for more than three-quarters of all plant life on Earth. What
characteristics/adaptations enable this plant type to be successful (structurally, at the cell
and tissue level, reproductive advantages, etc.)?
Describe the "relationship" that forms between rhizobium bacteria and their legume
hosts. How does it benefit either party? Are there any relative drawbacks to the
symbiosis? How can you (physically) tell if a plant has been infected with rhizobium (at
macro and micro levels)?
Several hormones act to counterbalance each other in plant physiology. Select two such
hormones, describe the effects they have individually on an organism, and explain how
they balance each other's effects on a plant.
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Study questions;
Yesterday I noticed that the basil plant I am currently cultivating has started to bud. Since
I use the plant's leaves in my salad I naturally don't want it to flower. The leading SAM is
where the budding has occured, so I cut it off at the base of the youngest true leaves.
Describe what will happen to my precious basil. (Your answer should include both the
function, impact, and the transportation of both auxin and cytokinin, as well as how they
relate to each other.)
Gibberellin is an important hormone produced by plants. Describe some of the major
functions of gibberellin. Why do germinating seeds produce this hormone?
What is the relationship between double fertilization in angiosperms and the use of
the hormone gibberellin (GA) to exit seed dormancy?
Explain the progression from aquatic to terrestrial environment for a plant and how that
has influenced its structure from haploid plants (i.e.mosses) to diploid plants (i.e.
angiosperms) (focusing primarily on the shift from gametophyte dominated to sporophyte
dominated).
How do plants respond chemically to light sensitivity if there is more light to one side,
and lack of light on the other?
Describe how plants are able to balance hormones when a change (environmental,
damage, etc. ) is experienced.
Several hormones act to counterbalance each other in plant physiology. Select two such
hormones, describe the effects they have individually on an organism, and explain how
they balance each other's effects on a plant.
Explain the progression from aquatic to terrestrial environment for a plant and how that
has influenced its structure from haploid plants (i.e.mosses) to diploid plants (i.e.
angiosperms) (focusing primarily on the shift from gametophyte dominated to sporophyte
dominated).
Using your knowledge of plant hormones and hormone responses how is it that auxins
can be used as a defoliant/herbicide, such as Agent Orange in the Vietnam War, when
plants (under normal conditions) use them to carry out a successful life?
Follow the path from pollen to seed. How have angiosperms evolved for reproduction on
land?
What adaptations have plants adopted to ensure their reproductive success and how do
these adaptations ensure success?
Describe the relationship between two hormones. Be sure to explain their functions and
transport, and how these factors contribute to their relationship.
Explain the difference between highly mobile nutrients and less mobile nutrients.
Select a plant hormone (auxin, cytokinin, giberellin, etc.) and discuss this
hormone in terms of its discovery, its receptor, its transport mechanism, its
functions, and describe its synthesis as well as any interactions that it may have
with other hormones.
Most plant hormones work by stimulating plant growth. Abscisic acid works
against these hormones and in high concentrations halts plant growth
altogether. Explain the ways that this “anti-growth” hormone could be
beneficial to plant development.
Compare and contrast two hormones and their effects/functions.
Describe in detail the role of hormones in seed germination.
Explain the stategy behind having Auxin and Cytokinin produced in their
respective location, and what each does. Why is it important to have a balance
of the two?
Of the hormones we studied in class, chose two and explain their Discovery,
Syntheisis location, transport, function(s), and receptors. Also briefly explain how
a plant, either defficient or in excess of the hormone, would differ from a plant
with normal hormone levels.
Explain characteristics of Abscisic Acid (ABA) including its effect on germination,
the relationship to Gibberlin, and it's role in the water transport.
Explain what procceses would be halted in a plant's seed germination phase change in the
absence of Gibberlin. Be specific.
Explain the two types of Nitrogen Assimilation. In your explanation describe the process
and route nitrogen takes to becoming fixated. How are Rhizobium so important to this
second way of nitrogen assimilation, and what is the ideal condition the plant would like
to have involving these to processes. example high nitrate with no rhizobium, or low
nitrate with rhizobium etc.. Why is this ideal condition better?
Explain the process an embryo sac goes through to get ready for fertilization and how it
functions to nurture the growing embryo?
Explain how a high auxin concentration in an Arabidopisis mutant would exhibit extreme
proliferation of lateral roots.
Hormones play a pivotal role in a plant’s ability to respond to environmental stress. How
do plants use hormones respond to environmental stress? And what roles do some
specific hormones play in the ability for plant’s to adapt to their environment?
Nitrogen is a macronutrient essential for plant growth and development. Describe how is
N2 gas is synthesized into a molecule used by plants? Which two Nitrogen-containing
molecules are roots able to absorb? Which organisms are responsible for producing
nitrogen-containing molecules found in the soil?
Thinking about signal transduction and root nodules, explain how an infection thread is
formed. What does this eventually do for the plant?
Describe 3 of the 6 plant hormones in depth, explaining why they are important to plant
development/survival, and how they were discovered.
Discuss the adaptations that have enabled plants, particularly angiosperms, to overcome
problems with reproduction, growth and development associated with life on land.
Cell elongation is one of many effects of the hormone auxin (IAA), which is synthesized
by the plant in order to increase it's primary growth, but explain why produce sellers
would also have an interest in using this hormone to inhance quantity or quality of
produce.
Iceburg lettuce has been shown to contain higher amounts of harmful chemicals than
other grocery store plants. Explain how the structure of lettuce and the location and
functions of the central vacuole contribute to these levels. How does this relate to
phytoremediation?
Describe the balance in concentrations of corresponding plant hormones, such as auxin
and cytokinin, and how two hormones interact to influence plant growth and
development.
Explain the steps plants take during the nutritional adaptation involving the symbiotic
relationship of nitrogen fixation and soil bacteria.
Hormones are very important to the development in plants. Please describe the hormone
that contributes to the triple response mechanism and explain the other functions this
hormone initiates.
What is the importance of hormones in the growth and development of a plant from seed
to mature plant? Make sure to include major roles of hormones talked about in class.
How can a plant recognize a specific type of rhizobia and why would the resulting
infection be important? What is the purpose of being so selective?
What role do hormones play in producing a seedless fruit.
Choose one plant hormone and describe what would happen to the plant if it was missing
that hormone.
List and describe 3 functions of auxin and give specific examples of its influence.