Page 119 - Science Course 1 (Book 1)

Mo4-L2: Key Concept Organizer

Directions: Put a check mark on the line in front of each true statement.
1. A. During cellular respiration, a plant produces sugar that it uses as food.
B. During photosynthesis, a plant produces sugar that it uses as food.
2. A. Organisms need light for growth, repair, movement, and other life processes.
B. Organisms need energy for growth, repair, movement, and other life processes.

3. A. Cellular respiration is the process of releasing energy by breaking down food.
B. Photosynthesis is the process of releasing energy by breaking down food.

4. A. Plants absorb light energy from the Sun and convert it into chemical energy in a process called
cellular respiration.
B. Plants absorb light energy from the Sun and convert it into chemical energy in a process called
photosynthesis.

5. A. The chlorophyll within chloroplasts is what gives most plants their green color.
B. The hydrogen atoms within chloroplasts are what give most plants their green color.

6. A. Photosynthesis occurs inside chloroplasts.
B. Photosynthesis occurs inside stomata

7. A. Carbon dioxide enters a leaf through stomata, combines with the hydrogen atoms, and forms
glucose, which is a type of sugar.
B. Oxygen enters a leaf through stomata, combines with the hydrogen atoms, and forms glucose,
which is a type of sugar.

Mo4-L2: Key Concept Check

Directions: Circle the term in parentheses that correctly completes each sentence.
Plants respond to external and internal stimuli. (1.) (External/Internal) stimuli include light, touch, and gravity.
(2.) (External/Internal) stimuli occur inside a plant in the form of (3.) (wastes/chemicals), called hormones, that
a plant produces. Plants produce many different hormones. They can affect growth, seed germination, or fruit
ripening. The hormones that promote growth (4.) (decrease/increase) the rate of mitosis and cell divisions.

Some hormones slow growth, and farmers can use them to help control weeds. One type of hormone can
cause seeds to germinate by starting the breakdown of the stored food in a (5.) (seed/leaf). This releases
energy needed for new (6.) (growth/germination). Another plant hormone often is used to speed up the

ripening of fruit that is sold in grocery stores.
Directions: On the line before each statement, write P if the statement describes phototropism, G if the
statement describes gravitropism, or T if the statement describes thigmotropism.

7. A plant grows toward a light source.
8. A plant responds to touch.

9. A plant responds to gravity.
10. The first root produced by a germinating seed grows downward.
11. A vine’s tendrils coil around another plant.

12. Growing toward a light source enables leaves and stems to receive the maximum
amount of light for photosynthesis.
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