Plant Responses to External and Internal Stimuli

Frank was out of town for a few days and when he returned, he noticed that his plant was very wilted. He watered the plant and put it in the sun. A few hours later, he noticed that it the leaves on the plant had perked up and looked fine again. The image shows the plants before and after the water and exposure to sunlight.

Why did this occur?

• The plants needed the water to help the leaves undergo photosynthesis.

• The plants needed to be put in the sun so the sunlight could attract the plant.

• The plants needed to be outside so it could be affected by the gravity of the Earth.

• The plants needed the water so the cells could expand and keep the plant upright.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS1-6

Billy orders a plant for his garden. When it was delivered, the roots and the plant stem were not growing straight out of the clay pot. Instead, the direction of their growth was in a 'sideways' direction. The diagram shows the direction the plant was growing when it was received by Billy.

Why is the most likely reason for the direction of the plant growth?

• The plant lost turgor pressure and changed it's growth direction.

• The plant was laid on it's side inside the package and geotropism caused the plant to change it's growth direction.

• The plant found light through the sealed package and phototropism caused the plant to change it's direction of growth.

• Plants normally grow in strange patterns until they reach a certain age.

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

Tags

NGSS.MS-LS1-5

Which of these best completes the concept map?

• calcium

• friction

• gravity

• chemical imbalance

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NGSS.MS-LS1-5

If the top portion of plants grow "up," explain why a small tree on a hillside does not grow straight out from the hillside?

• The tree is growing toward water.

• The tree is resting on the hillside.

• The tree is leaning toward the top of the hill so rain won't wash it off.

• The tree's roots and trunk are growing in response to gravity.

The diagram illustrates a seed germinating. Many forces, including responses to moisture, temperature, and gravity are at work in this process. Which part of the seedling is demonstrating a negative response to gravity and which is showing a positive response to gravity?

• I is negative and III is positive.

• IV is negative and II is positive.

• II is negative and III is positive

• III is negative and IV is positive.

he 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.

Tags

NGSS.MS-LS1-5

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?

• gravity

• oxygen

• radiation

• temperature

Tags

NGSS.MS-LS1-5

The diagram illustrates a seed germinating. Many forces, including responses to moisture, temperature, and gravity, are at work in this process. Which part of the seedling demonstrates a negative response to gravity?

• I

• II

• III

• IV

The tip of a plant's root is covered by a root cap. The root cap produces a slimy, slippery substance. Which of the following is the MOST likely purpose for this substance?

• absorbing water and nutrients in soil

• reducing the plant's need for soil

• helping roots grow through the soil

• anchoring the plant to the soil