IGCSE Biology December 2022 Monthly Test

The diagram shows a plant.

What is the pathway taken by most of the water absorbed by this plant?

• X ➔ Y ➔ Z

• W ➔ Y ➔ Z

• Z ➔ Y ➔ X

• Z ➔ Y ➔ W

For which process is a root hair cell adapted?

• absorption of mineral ions

• support of stem

• translocation of sucrose

• transport of oxygen

In a section through a plant, a student found a group of long, microscopic structures. The structures lacked end walls, cytoplasm and nuclei.

Which identification and reason best matches the student's observations?

• root hair cells - they do not contain a nucleus when mature

• root hair cells - they do not contain cytoplasm to absorb water

• xylem vessels - they can support the plant better without cytoplasm

• xylem vessels - they need to be hollow to carry water efficiently

The diagram shows a cross-section through a plant root.

Q shows the part that is stained red when the root is placed in water containing a red dye.

What is found at Q?

• guard cells

• palisade cells

• phloem

• xylem

The diagram shows a plant shoot and the same shoot six hours later.

Which change in environmental conditions could cause this change in the shoot?

• a decrease in available water

• a decrease in light intensity

• a decrease in wind speed

• an increase in humidity

A celery stalk is placed in a beaker of blue dye. Once the dye reaches the leaves, the stalk is taken out and cut in half.

Which diagram shows the appearance of the cut end of the stalk?

• 
• 
• 
• 

Which substances are transported in the phloem?

• amino acids and starch

• amino acids and sucrose

• protein and starch

• starch and sucrose

The diagram shows one of the stomata of a leaf, and some of the cells that are near it.

During transpiration, what describes the movement of water at X and at Y?

• X - evaporation

  Y - diffusion

• X - evaporation

  Y - osmosis

• X - osmosis

  Y - diffusion

• X - osmosis

  Y - osmosis

Potato plants start to grow from old stem tubers in spring.

What is a source and what is a sink at this stage of the life cycle?

• Leaves are a source and roots are a sink.

• Stem tubers are a source and new shoots are a sink.

• Flowers are a sink and roots are a source.

• Leaves are a source and stem tubers are a sink.

Into which chamber of the heart does oxygenated blood enter?

• left atrium

• left ventricle

• right atrium

• right ventricle