Review Midterm Unit 1 - Photosynthesis and Carbon Cycles

Why do plants need magnesium?

• Make chlorophyll

• Make protein

• Absorb water

• Transport blood

A scientist investigated whether giving plants different quantities of magnesium affected their growth.

He measured growth by counting the number of new leaves produced.

Write down a hypothesis he could test in his investigation.

• With more magnesium, less leave grows

• Increasing the amount of magnesium given to plants will increase the number of new leaves produced

• With less magnesium, more new leaves grows

• More water given, the more magnesium produced

Here are his results.

• 0.5 mg magnesium: 3 new leaves

• 1.0 mg of magnesium: 5 new leaves

• 1.5 mg of magnesium: 6 new leaves

• 2.0 mg of magnesium: 4 new leaves

• 2.5 mg of magnesium: 1 new leaf

Which amount of magnesium gives the greatest number of new leaves growth?

• 0.5 mg

• 1.0 mg

• 1.5 mg

• 2.0 mg

Complete the sentences. Choose the correct word

67 million years ago, an _________________________ collided with the Earth.

• asteroid

• photosynthesise

• climate

• mass

Complete the sentences. Choose the correct words.

The _________________________ of the Earth changed, as it became cooler. Many animals could not survive because they did not have enough food. There was a _________________________ extinction.

• climate, asteroid

• climate, photosynthesise

• climate, weather

• climate, mass

Complete the sentences. Choose the correct word.

Less light could reach the ground, so plants could not _________________________

• asteroid

• photosynthesise

• climate

• mass

Here are some statements about the carbon cycle.

Tick (✓) the two correct statements.

• Plants take carbon dioxide from the air when they respire.

• Decomposers obtain their carbon from dead animals and plants.

• Combustion of fossil fuels adds carbon dioxide to the air.

• Carbon dioxide is returned to the air by photosynthesis.

Explain the difference between chloroplasts and chlorophyll.

• Chloroplast is located in the chlorophyll which is orange pigment.

• Chloroplast is located in the chlorophyll which is green pigment.

• chlorophyll which is orange pigment is located in chloroplast which is part of cell.

• chlorophyll which is green pigment is located in chloroplast which is part of cell..

Choose the correct word to match each description.

This gas is used by plants in photosynthesis ____________

• chloroplast

• chlorophyll

• oxygen

• carbon dioxide

This gas is made by plants in photosynthesis.

• soil

• oxygen

• carbon dioxide

• chlorophyll

• chloroplast