Name: ______________________________________________
Grass Growth Experiment
1. How tall was the control plant on day 7?
a. 2.5 cm
b. 3 cm c. 2 cm
d. 2.25 cm
2. On which day did Plant B have a height greater than 1.5 cm but less than 2cm?
a. Day 2
b. Day 4
c. Day 6
d. Day 8
3. On which day were the test plants most likely moved to their new locations?
a. Day 1
b. Day 3
c. Day 5
d. Day 7
4. Which reasoning best explains the decline in height for Plant B between Day 7 and Day 10?
a. No light meant the plant couldn’t photosynthesize and thus became shorter.
b. The plant is growing smaller amounts without the light it used to have.
c. The plant is wilting over.
d. The plant is using up stored energy it has saved.
5. Which conclusion best summarizes the results in this data table?
a. Putting plants in a closet is very bad for its growth because there is no sunlight.
b. Moving plants to a different location once they start growing can affect their growth.
c. Plants placed on a windowsill will grow taller than other plants.
d. More sunlight results in taller plant growth while no sunlight stops plant growth.
6. If you placed Plant A in the closet on Day 10, how tall would you expect it to be on Day
11?
a. 2.5 cm
b. 3 cm
c. 3.5 cm
d. 4 cm
Duckweed Growth
Experimental Procedure:
Mix four fertilizer and water solutions – 0% fertilizer, 0.5% fertilizer, 1% fertilizer, 2% fertilizer. Label
400 clear plastic cups with group name and type of water (0, 0.5%, 1%, 2%).
Add duckweed to the
cups of water until you have 10 leaves (not 10 plants). Set cups in appropriate light. Observe cups
daily and record changes by counting leaves and noting other things.
Take a look at the cups of each
group.
1. Approximately how many leaves were on the duckweed plants in water with a 0.50% on Day
10?
a. 50 leaves b. 23 leaves c. 60 leaves d. 75 leaves
2. Which fertilizer concentration produced closest to 50 leaves by Day 15?
a. 0%
b. 0.50%
c. 1%
d. 2%
3. What are the independent and dependent variables in this experiment?
a. Independent = number of leaves Dependent = amount of sunlight
b. Independent = amount of fertilizer Dependent = number of leaves
c. Independent = number of leaves Dependent = amount of fertilizer
d. Independent = amount of sunlight Dependent = number of leaves
4. Which of these statements best summarizes the data in the table?
a. Using fertilizer helps duckweed grow more leaves.
b. A concentration of fertilizer greater than 0.50% actually decreases the leaf production in
duckweed plants.
c. Duckweed plants don’t seem to respond at all to fertilizer in the water.
d. No conclusion can be made without more trials.
5. What would most likely have happened if the experimenter had tested a fertilizer
concentration greater than 2%?
a. We would see leaf numbers very similar to those of 2%.
b. We would see more leaves than with all the other tests we’ve done so far.
c. We would see the same amount of leaves as the other fertilizer amounts.
d. We would see leaf numbers greater than 0.50%.
Duckweed and Water Acidity Levels
What is pH?
In chemistry, pH is a measure of the
acidity or basicity of an aqueous solution.
Solutions with a pH less than 7 are said to
be acidic and solutions with a pH greater
than 7 are basic or alkaline. Pure water has
a pH very close to 7.
1. Which of the ponds in the Field Data has acidic pond water?
a. Pond D
b. Pond B
c. Pond B and Pond C
d. Pond A and Pond D
2. What is the pH level of lemon juice?
a. 1
b. 2
c. 3
d. 4
3. Which of these statements best summarizes how duckweed reacts the pH of water?
a. Duckweed seems to grow best in neutral water – not acidic and not basic.
b. Duckweed seems to grow best in slightly acidic water.
c. Duckweed seems to grow best in slightly basic water.
d. Duckweed seems to grow best in the extremes – very acidic and very basic water.
4. Approximately how many duckweed plants would you expect to find in water with a pH of
11?
a. 350 plants b. 400 plants c. 250 plants d. 200 plants
5. What would you expect the acidity of Pond A to be if campers washed dishes in it using Soft
Soap?
a. 4
b. 6
c. 7
d. 10
6. If I used Soft Soap to wash my hands in a tub of water growing duckweed, how would I expect
the duckweed to respond?
a. the duckweed would probably die off
b. the duckweed population would decrease some
c. the duckweed population would increase some
d. the duckweed population would not change
1. Which of the fertilizer brands seemed to have the best growth results?
a. Granny’s Bloomers b. Jobe’s House Plant Spikes c. Miracle Gro d. Kmart Fertilizer
2. When plants were treated with Kmart Fertilizer, how tall did they grow?
a. 14 cm
b. 22 cm
c. 25 cm
d. 28 cm
3. How much taller will plants grow when treated with Granny’s Bloomers instead of Jobe’s
Plant Spikes?
a. about 10 cm b. about 13 cm c. about 15 cm d. about 6.5 cm
4. Name one of the controls that must have been in place during this experiment.
a. the type of fertilizer used on the plants
b. the amount of fertilizer used on the plants
c. the amount of sunlight the plants received
d. the amount of growth of the plants
5. Which of these statements best summarizes these experimental results?
a. Any fertilizer will help a plant grow taller.
b. Not all fertilizers will promote gains in plant heights.
c. Fertilizers don’t do much to increase plant height.
d. Fertilizers help plants grow taller but not always to the same degree.
6. Think about the previous graphs you’ve seen involving fertilizers. How would the results be
different if the concentration of fertilizer solution used was increased by several %?
a. All the plants treated with fertilizer would probably have grown even taller.
b. All the plants treated with fertilizer would probably have grown the same amount.
c. All the plants treated with fertilizer would probably have grown a little less.
d. All the plants treated with fertilizer would probably have grown less than the control.
Plants Receiving Different Amounts of Sunlight
Procedure:
Potted dwarf daisy plants
were used to test the effect of
different lengths of daylight
on plants. The average growth
of all test plants exposed to
each amount of daylight are
shown to the left. The plant
measurements were taken in
centimeters.
1. How tall were the plants receiving 8 hours of sunlight after 4 weeks?
a. 4 cm
b. 7 cm
c. 10 cm
d. impossible to tell from this graph
2. If a plant receives 8 hours of sunlight a day while another plant receives 12 hours of sunlight a
day, which of the following results would you most likely see?
a. The plants would basically grow the same overall height.
b. The plant receiving 8 hours would grow significantly taller.
c. The plant receiving 12 hours would grow significantly taller.
d. The plants would grow the same height as the control.
3. How would you explain the small bit of growth the plant without sunlight showed?
a. The plant can still photosynthesize a little even if there isn’t any sunlight.
b. The plant probably used the minerals in the soil to grow.
c. The plant probably used stored energy to still grow a little.
d. The plant cannot grow at all without any sunlight.
4. After 2 weeks of time, what kind of growth would you expect from plants exposed to 20 hours
of sunlight per day?
a. about 5 cm
b. about 8 cm
c. about 10 cm
d. about 12 cm
5. What was one of the controls for this experiment?
a. the height of the plant in centimeters
b. the number of hours of sunlight shining on the plants
c. the amount of water given to the plants
d. the type of experiment
6. After viewing this data, students commented on their understanding of what the data meant.
Which of these students do you agree with?
a. Student A – The more sunlight you give a plant, the more it can photosynthesize and grow.
b. Student B – Plants must only be able to photosynthesis a certain number of hours each day.
c. Student C – Plants don’t need sun to photosynthesize to grow tall.
d. Student D – Too much sunlight can deter a plant from reaching its maximum height.
The word bulb describes plants that grow from an underground mass of food storage tissue. True
bulbs, like tulips and daffodils, contain a complete miniature plant surrounded by fleshy scales
attached to a basil plate from which plants grow. The scales are mostly carbohydrates and nourish the
young plant. True bulbs can be either truncated, with a papery covering such as onion or tulip, or nontunicate, with no paper covering such as over the fleshy scale like leaves of a lily.
If a bulb is sliced in half horizontally, you will see rings formed by the scale leaves. These scale leaves
store food for use by the bulb as it grows. If you slice a bulb vertically, you should be able to find
leaves, stems, and even flower buds.
1. Where does a Dutch Iris get the energy for the first 10 inches of its growth?
a. nutrients in the ground
b. photosynthesis
c. the bulb
d. the sun
2. How tall does a Daffodil need to grow before it has leaves?
a. about 9”
b. about 2”
c. about 24”
d. 0”
3. If I wanted to plant a garden that blooms all year, which of the following should I plant along
with Hycinths and Dutch Irises?
a. Crocus b. Mid-season Tulips
c. Mini Daffodils
d. Late Tulips
4. Students preparing to plant a garden studied the above information. Which of these students do
you agree with?
a. Overall, late blooming bulbs should be planted earlier in the year.
b. Overall, early blooming bulbs should be planted shallower.
c. Overall, early blooming bulbs should be planted earliest, then mid blooming, and last late blooming.
d. Overall, bulbs should all be planted at the same time and at the same depth.