Year 3 Science What plants need: check-up and practice test questions

Method. Think about what the roots take in from the soil.

1. Think about water. The roots take in water from the soil.
   water
2. Think about nutrients. The roots also take in nutrients from the soil.
   nutrients
3. Write the answer.
   Accept water or nutrients.

Check. Water and nutrients both come from the soil. ✓

Method. Think about the gas that leaves take in through their holes.

1. Think about the leaves. Leaves take in a gas from the air through tiny holes.
   tiny holes
2. Name the gas. The gas is carbon dioxide.
   carbon dioxide
3. Write the answer.
   carbon dioxide

Check. Leaves use carbon dioxide to make food. ✓

Method. Think about the part of the plant in the soil.

1. Think about the soil. The nutrients are in the soil.
   in the soil
2. Name the part. The roots take in nutrients from the soil.
   roots
3. Write the answer.
   roots

Check. The roots take in nutrients and water. ✓

Method. Take the height after 1 hour away from the height after 3 hours.

1. Read the two heights. The line was 3 cm after 1 hour and 9 cm after 3 hours.
   3 and 9
2. Find the rise. The rise is the bigger height minus the smaller height.
   9 − 3 = 6
3. Write the answer.
   6 cm

Check. 3 + 6 = 9, so the answer is right. ✓

Method. Compare the number of plants in each pot.

1. Read pot A. Pot A has 1 plant, so the plant has more room.
   1 plant
2. Read pot B. Pot B has 3 plants, so they must share the light, water and nutrients.
   3 plants
3. Choose the pot. So pot A gives each plant more room.
   A
4. Write the answer.
   A

Check. Fewer plants in a pot means more room for each. ✓

Method. Think about the plant with a thick stem.

1. Think about the stem. A thick stem can store water.
   stores water
2. Name the plant. The cactus has a thick stem that stores water.
   cactus
3. Write the answer.
   cactus

Check. A cactus needs little water. ✓

Method. Think about what nutrients are, and where food is made.

1. Think about nutrients. Nutrients are substances from the soil that help the plant to grow.
   not food
2. Name where food is made. Plants make food in their leaves, using light, water and carbon dioxide.
   in the leaves
3. Write the answer.
   No. Accept any answer that says plants make food in their leaves, using light, water and carbon dioxide.

Check. Nutrients are not food. ✓

Method. Think about the tubes named in this chapter.

1. Read the chapter. Water travels up through tiny tubes called xylem.
   xylem
2. Write the name. The scientific name is xylem.
   xylem
3. Write the answer.
   xylem

Check. Xylem tubes carry water up the plant. ✓

Method. In a fair test only the light changes.

1. Find the thing that changes. The amount of light changes.
   light changes
2. Name a thing that stays the same. The pot, the soil, the water and the seed stay the same.
   pot, soil, water
3. Write the answer.
   Accept any one thing that stays the same, such as the pot, the soil, the amount of water or the type of seed.

Check. Only one thing changes in a fair test. ✓

Method. Think about what roots need from the soil.

1. Think about air. Roots need some air as well as water.
   air
2. Give the reason. Soggy soil leaves very little air for the roots.
   little air
3. Write the answer.
   Accept any sentence that says roots need some air to stay healthy, and soggy soil leaves very little air for them.

Check. Roots need air, and soggy soil has very little. ✓

Method. Think about the gas that leaves use to make food.

1. Think about the leaves. Leaves take in a gas from the air to make food.
   gas from the air
2. Name the gas. The gas is carbon dioxide.
   carbon dioxide
3. Write the answer.
   carbon dioxide

Check. Carbon dioxide is taken in through the leaves. ✓

Method. Think about the substances that help a plant to grow well.

1. Think about the soil. Plants take nutrients from the soil through their roots.
   from the soil
2. Name one. Nitrogen and phosphorus are two nutrients that plants take in.
   nitrogen or phosphorus
3. Write the answer.
   Accept any one nutrient, such as nitrogen or phosphorus.

Check. Nitrogen and phosphorus are both nutrients. ✓

Method. Find the drops in the key.

1. Read the key. The key shows water as drops.
   drops
2. Read the colour. The water drops are blue.
   blue
3. Write the answer.
   blue

Check. Water is shown in blue. ✓

Method. Think about what leaves need to make food.

1. Think about the leaves. Leaves use light to make food.
   light
2. Give the reason. With no light in the dark, the leaves cannot make food, so the plant grows weakly.
   no food, weakly
3. Write the answer.
   Accept any sentence that says the plant cannot make food from light in the dark, so it grows weakly.

Check. Light is needed for the leaves to make food. ✓

Method. Think about what crowded plants have to share.

1. Think about sharing. Crowded plants share the light, water and nutrients.
   share
2. Give the reason. So each plant gets less of what it needs.
   gets less
3. Write the answer.
   Accept any answer that says crowded plants share the light, water and nutrients, so each plant gets less.

Check. Less of each need means slower growth. ✓

Method. Look at the blue arrow beside the stem.

1. Read the arrow. The blue arrow points to the top of the plant.
   points up
2. Name the direction. So water moves up the stem.
   up
3. Write the answer.
   up

Check. Water goes up from the roots to the leaves. ✓

Method. Find the two heights, and then say which part the water travelled through.

1. Read the two heights. The line was 3 cm after 1 hour and 17 cm after 5 hours.
   3 and 17
2. Find the rise. The rise is the bigger height minus the smaller height.
   17 − 3 = 14
3. Name the part. The coloured water travelled up through the stem, in tiny tubes.
   the stem
4. Write the answer.
   14 cm, through the stem

Check. 3 + 14 = 17, so the answer is right. ✓

Method. Think about what a fair test changes and keeps the same.

1. Find the thing that changes. The class changes the amount of light.
   light changes
2. Find two things that stay the same. The pot, the soil, the water and the type of seed stay the same.
   pot, soil, water, seed
3. Put the parts together. Two things kept the same, such as the pot and the water, and the light as the one thing changed.
   two kept, light changed
4. Write the answer.
   Accept any two things that stay the same, such as the pot, soil, water or type of seed. The one thing that changes is the light.

Check. Only the light changes in a fair test. ✓

Method. List the five needs, then give the reason for light.

1. List the needs. The five needs are air, light, water, nutrients from the soil and room to grow.
   five needs
2. Think about light. Leaves use light to make food.
   light makes food
3. Give the reason. So light is needed to make food in the leaves.
   make food
4. Write the answer.
   Air, light, water, nutrients from the soil and room to grow. Light is needed to make food in the leaves.

Check. Five needs are named, and light is used to make food. ✓

Method. Think about what nutrients do and what food is.

1. Read the claim. Mo says a plant does not need nutrients.
   claim
2. Think about food. The plant makes its own food in its leaves, but it still needs nutrients from the soil.
   food in leaves
3. Think about nutrients. Nutrients help the plant to grow well, so Mo is not right.
   not right
4. Write the answer.
   No. Accept any answer that says nutrients are taken from the soil to help the plant grow well, and are not food.

Check. A plant makes its food, and still needs nutrients to grow well. ✓