1. District Science Grade 7 Unit 03 Draft

2. A sunlight B gravity C osmosis D water1
In a germinating seed, the downward growth of roots and upward growth of leaves and stems are the plant's responses to —
A sunlight B gravity C osmosis D water
2 Scientists on a space shuttle mission studying plant growth would probably see that the plants on the space shuttle do not grow in the same direction and pattern as those on Earth. Scientists working in space would MOST LIKELY be studying the effects of which of the following stimuli on plant growth?
F gravity G oxygen H radiation
J temperature
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3. I is negative to light, and III is positive to gravity.
3 The diagram illustrates a seed germinating. Many forces, including responses to moisture, light, temperature, and gravity are at work in this process.
Which of the following correctly describes two of the seedling's responses to stimuli?
I is negative to light, and III is positive to gravity.
IV is negative to temperature, and II is negative to gravity.
II is negative to light, and III is positive to gravity.
II is positive to gravity, and IV is positive to moisture.
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4. Picture A
Picture B
4 The pictures above show a gerbera daisy that has experienced a change called wilting. Which of the statements below best describes what has happened from Picture A to Picture B?
Water entering the plant increased the turgor pressure in the cells of the flower.
Water entering and leaving the cells of the flower at equal rates kept turgor pressure equal.
Lack of water in the soil decreased the turgor pressure in the cells of the flower.
J Lack of sunlight on a cloudy day caused the flower to lose turgor pressure.
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5. What must happen for a seed to emerge from the soil as a seedling?
The soil must erode and expose the seed to the sunlight.
An animal searching for food must disrupt the soil.
The seed must exert a force to push a shoot up through the soil.
Another plant must die to make room for the new plant.
Seeds that are planted upside down are still able to grow into mature plants. Which explanation best explains this phenomenon?
The roots change into branches, and the branches turn into roots.
The roots grow toward the force of gravity, and the shoots grow away.
The plant will become a smaller version of a mature plant.
J Roots always grow toward the dark, and shoots grow toward the light.
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6. Gravity pulls down on the seed coat B
7 In order for an embryo plant to emerge from a seed and grow into a seedling, the seed coat must split open.
Which diagram illustrates the force exerted by turgor pressure to split open the seed coat? A
Gravity pulls down on the seed coat B
Gravity pushes up on the seed coat C
Water from the soil pushes in through the seed coat D
Water within the seed pushed out against the seed
coat
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7. 8 Which part of the plant above demonstrates the greatest amount of turgor pressure?
Part A
Part B H Part C J Part D
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8. 9
A bean plant grown on Earth and a bean plant grown aboard the International Space Station are MOST likely to differ in the —
color of their leaves
shape of their root systems
nutrients they need to survive
way they respond to direct light
10 An organism's response to the force of gravity is called-
phototropism
geotropism
thigmotropism
J hydrotropism
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