(outdated) Crop Plants

Complete Table 7.1 by using the letters A, B or C from Fig. 7.1 to show the location of several compounds associated with photosynthesis in C4 plants.

You may use A, B and C once, more than once, or not at all.

Table 7.1

Explain why the cells in C form a tight ring around the cells in B.

Several enzymes have a role in the light independent stage of photosynthesis.

Fig. 7.2 shows the activity of one of these enzymes at different temperatures for a C3 plant, Pisum sativum, and a C4 plant, Amaranthus hypochondriacus.

Describe the differences between the two curves and suggest explanations for these differences.

Describe and explain the structural features of a wind-pollinated plant.

Discuss the benefits of cross-pollination.

Describe and explain the structural features of a wind-pollinated plant.

Discuss the benefits of cross-pollination.

Explain the significance of cereal crops in the human diet.

Describe and explain how gibberellins are involved in the germination of wheat or barley seeds.

Explain the meaning of the term self-pollination.

Explain why cross-pollination may be more beneficial to a species than self-pollination.

Describe the effect of exposure to the air on maize pollen.

A wild relative of maize, called teosinte, grows in Mexico. There are concerns that pollen from genetically-modified maize could pollinate wild teosinte and transfer new genes to it.

Suggest how the results shown in Fig. 5.1 could be used to devise strategies that would reduce the possibility of this happening.

Fig. 4.1 shows a light micrograph of a section through a wheat grain.

The structure of a wheat grain is very similar to that of a maize fruit.

On Fig. 4.1, use label lines and letters to label each of the following parts.

A endosperm

B fused testa and pericarp (fruit coat)

C embryo

Wheat grains are ground to make flour, which can be used for making bread.

Whole grain flour is made from the complete wheat grain.

Refined (white) flour is produced from wheat grains from which the embryo, aleurone layer and the fused testa and pericarp have been removed.

Table 4.1 shows the carbohydrate, protein and dietary fibre content of bread made from whole grain flour and white flour.

Table 4.1

With reference to the structure of a wheat grain, explain the differences between the composition of the two types of bread shown in Table 4.1.

Foods containing starch have lower GIs than foods containing glucose.

Foods containing starch made up mostly of amylose have lower GIs than foods containing starch made up mostly of amylopectin.

Describe the effect of increased intake of whole cereal grains on the risk of developing type II diabetes.

Explain why the results in Table 4.2 cannot be used to make a direct comparison of the effects of consuming whole cereal grains and refined cereal grains on the risk of developing type II diabetes.

The results in Table 4.2 suggest that eating large quantities of fruit may slightly increase the risk of developing type II diabetes.

Suggest a reason for this.

State the structural features that are characteristic of a wind-pollinated flower and explain how each feature contributes to successful pollination.

Suggest how self-pollination could help the population of hybrid plants to increase.

With reference to Fig. 4.1 suggest how the flowering habit of maize encourages wind pollination.

In a maize plant, the anthers normally ripen and release pollen before the stigmas are mature and ready to receive pollen. This encourages cross-pollination.

Explain two potential advantages of cross-pollination to a plant species.

explain the difference between the rates of photosynthesis of wheat and maize at 28 °C.

With reference to Table 4.1 suggest reasons for the difference in protein content between wheat and white rice.

State, giving a reason, which type of grain would be beneficial for a person with anaemia.

Explain the meaning of the term self-pollination.

Explain why cross-pollination may be more beneficial to a species than self-pollination.

Describe the effect of exposure to the air on maize pollen.

Describe the function of the endosperm.

Brown rice includes the pericarp and testa, whereas in white rice these have been removed during milling, along with most of the aleurone layer.

Table 5.1 shows the nutrient content of samples of white and brown rice.

Table 5.1

With reference to the structure of rice grains, suggest why brown rice contains more protein than white rice.

Explain why brown rice contains less carbohydrate per gram than white rice.

Explain why the grains of cereals such as rice are staple foods in many parts of the world.