Name
Date
Class
Plant Responses and Growth
On a separate sheet of paper, explain three different types of response a plant may have
to light—its direction or the length of time it lasts.
123C
Name
Date
Class
Plant Responses and Growth
Understanding Main Ideas
Answer the following questions on a separate sheet of paper.
1. List three stimuli that produce responses in plants and give the name
for each response.
2. What is gravitropism? How can a plant show both a positive and a
negative gravitropism?
3. What is photoperiodism? What is its effect in many plants?
4. What happens when a plant enters a state of dormancy?
Building Vocabulary
Match each term with its definition by writing the letter of the correct definition in the
right column on the line beside the term in the left column.
5.
critical night length
a. a hormone that controls a plant’s response to light
6.
auxin
b. a plant that flowers when the nights are shorter
than
a critical length
7.
short-day plant
c. a plant’s growth response toward or away from a
stimulus
8.
long-day plant
d. a chemical that affects the growth and
development
of a plant
9.
hormone
10.
day-neutral plant
11.
tropism
e. a plant whose flowering cycle is not sensitive to
periods of light and dark
f. a plant that flowers when the nights are longer
than
a critical length
g. the number of hours of darkness that determines
whether or not a plant will flower
123D