Plant Nutrition

Complete these sentences about chlorophyll by writing suitable words in the gaps.

A chlorophyll molecule contains carbon, hydrogen, oxygen, nitrogen and an atom of ______ .

Chlorophyll molecules are found in plant cells in structures called ______ .

The type of leaf cells that contain the most chlorophyll are the ______ cells.

Chlorophyll molecules trap sunlight energy and this is used by plants to produce glucose.

Glucose can then be converted to ______ to be transported around the plant.

Glucose can also be converted to ______ to make cell walls.

Mistletoe is a parasitic green plant that can often be seen growing attached to trees.

Fig. 4.1 shows some mistletoe growing on the branch of a tree.

Most plants have about $1\,\text{mg}$ of chlorophyll in $100\,\text{g}$ of their leaves.

Mistletoe, however, has about $0.4\,\text{mg}$ of chlorophyll in $100\,\text{g}$ of its leaves.

Mistletoe seeds are stuck to the branches of trees by birds. The seeds germinate to produce special roots that grow into the phloem of the tree branch.

Suggest why mistletoe grows these special roots.

Describe and explain the pattern of results between a light intensity of 20 and 30 arbitrary units.

Draw a curve on Fig. 6.1 to show the pattern of results that would be expected from this second investigation.

State the name of the product of photosynthesis that contains carbon atoms.

______

Outline the uses made by a plant of named carbohydrates.

The tomato plants carry out photosynthesis.

Describe the process of photosynthesis.

Suggest reasons why this is an advantage to the farmer.

Suggest one disadvantage, other than cost, of growing plants in this way.

Explain how this graph shows that light intensity is the limiting factor for photosynthesis at light intensity P but not at light intensity Q.

Name one environmental condition that could be limiting photosynthesis at light intensity Q.

Describe how a plant takes in carbon dioxide from the air and mineral ions from the soil.

Outline how a named mineral ion taken in by a plant from the soil is made available for use in the leaves of the plant to produce chlorophyll.

Use the information in the graph to describe the effect on crop yield of using an increasing mass of fertiliser.

The nitrogen in the fertiliser is in the form of nitrates.

Describe how the nitrogen in the fertiliser is absorbed by crop plants and used to give an increased yield.

Suggest and explain why a farmer may decide to use a mass of fertiliser per hectare which is less than that needed for a maximum crop yield.

Name one type of mineral ion, other than nitrate, that is required by a plant and state its importance to the plant.

type of mineral ion ______

importance to plant ______

Explain how plants that live in the water contribute to the changes in concentration of dissolved carbon dioxide shown in the graph.

Draw a line on the graph above to show how the concentration of dissolved oxygen in the water of the same pond is likely to change over the same period of time.

Carbon dioxide dissolves in water to form an acidic solution. The higher the concentration of dissolved carbon dioxide, the lower the pH.

Ammonia is a toxic chemical found in ponds, that may harm fish.

The graph shows how the concentration of dissolved ammonia in the water of a pond changes as the pH changes.

Use this graph and the graph on page 8 to suggest and explain at which time of day fish that live in the pond are most likely to be affected by the toxic effects of ammonia.

Draw a ring around the correct time of day.

time of day sunrise midday sunset

explanation ______

Explain why most living organisms depend on photosynthesis.

Explain why increasing the light intensity in which a plant is growing does not necessarily increase its rate of photosynthesis.

Explain how humans are dependent upon the process of photosynthesis.

State and explain the appearance of a plant that lacks each of the following ions.

magnesium
______

nitrate
______