Name ______________________________ Class ___________________ Date __________________
Section 5: Plant Hormones and Responses
Study Guide 22-5 and Vocab
1. A chemical messenger formed in one part of an organism that stimulates or
suppresses cell activity in another part of the organism is called a(n)
________________.
2. Plant hormones are sometimes released in response to _____________
changes and sometimes in response to internal changes in the plant.
Complete the chart below by filling in the blanks with the names of the four main
groups of plant hormones.
Plant Hormone
Controls processes involved in
3. _________________
ending seed dormancy
starting germination
promoting rapid growth of new seedlings
4. _________________
the ripening of fruits
5. _________________
the final stage of cell division
the growth of roots and side branches
the development of seeds and fruits
slowing the aging of leaves and other plant organs
6. __________________
lengthening of cells in the growing tip of a plant
preventing growth of new branches
tropisms
In the space provided below, illustrate the process of phototropism as it
occurs at the cellular level. Use Figure 5.3 as a reference. Label areas of high
auxin concentration.
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
1
Plant Growth, Reproduction, and Response
Name ______________________________ Class ___________________ Date __________________
phototropism
thigmotropism
rapid response
photoperiodism
gravitropism
______________________
7. growth in response to being touched
______________________
8. response to being touched not involving growth
______________________
9. growth in response to gravity
______________________
10. response to changing lengths of day and night
______________________
11. growth in response to light
What’s the difference between a sporophyte and a gametophyte?
What’s the difference between a sepal and a petal?
What’s the difference between a stamen and a carpel?
What’s the difference between seed dormancy and germination?
What’s the difference between regeneration and vegetative reproduction?
Plant hormone involved in the lengthening of plant cells in the growing tip
Plant hormone involved in the dramatic growth of seedlings, flower stalks, and fruits:
Plant hormone involved in the dramatic growth of seedlings, flower stalks, and fruits:
Plant hormone involved in cytokinesis and the growth of side branches:
Plant hormone involved in the ripening of fruit:
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
1
Plant Growth, Reproduction, and Response
Name ______________________________ Class ___________________ Date __________________
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
2
Plant Growth, Reproduction, and Response