GCSE BIO ECOLOGY adaptation Cycling; carbon dioxide concentratio

This question is about the effects of deforestation and agriculture. The processes of photosynthesis and respiration affect the carbon dioxide concentration in the air. Figure 1 shows the changes in the carbon dioxide concentration in the air in a tropical rainforest during one day. The data are mean daily values over a whole year. Explain what causes the changes in the carbon dioxide concentration in the air: • from 0 to 6 hours Use information from Figure 1.

• (0 to 6h):in the dark so (only) respiration occurs

• (0 to 6h):in the dark so (only) photsynthesis occurs

• (0 to 6h):in the light so (only) respiration occurs

• (0 to 6h):in the light so (only) photosynthesis occurs

This question is about the effects of deforestation and agriculture. The processes of photosynthesis and respiration affect the carbon dioxide concentration in the air. Figure 1 shows the changes in the carbon dioxide concentration in the air in a tropical rainforest during one day. The data are mean daily values over a whole year. Explain what causes the changes in the carbon dioxide concentration in the air:

• from 8 to 12h

Use information from Figure 1.

• (8 to 12h):in the dark so photosynthesis (rate) is slower than respiration (rate)

• (8 to 12h):in the dark so respiration (rate) is faster than respiration (rate)

• (8 to 12h):in the light so photosynthesis (rate) is slower than respiration (rate)

• (8 to 12h):in the light so photosynthesis (rate) is faster than respiration (rate)

Which statement is True

Use information from Figure 1.

• uptake of carbon dioxide by respiration is slower / less than output by respiration)

• uptake of carbon dioxide by photosynthesis is greater / faster than output by respiration

• uptake of carbon dioxide by respiration is greater / faster than output by photosynthesis)

• uptake of carbon dioxide by photosynthesis is lower / slower than output by respiration)

Explain why replacing rainforest with maize will increase the carbon dioxide concentration in the air after one year. Use information from Figure 1 and Figure 2.

click on the TRUE ones

• field of maize takes in less carbon dioxide per day than rainforest

• maize takes in carbon dioxide for a shorter amount of time

• field of maize takes in more carbon dioxide per day than rainforest

• maize takes in carbon dioxide for a higher amount of time

Explain why the scientists presented their results as percentages.

• different areas started with different numbers (of species)

• different areas started with different numbers of trees

During the 100 years, the biodiversity of trees in the regenerating rainforest increases. Give one other conclusion you can make from Figure 3.

• number of tree species decreased rapidly at first

• the number of tree species increases more slowly later

• biodiversity increases

•  beyond about 50 years there were more tree species than in the original rainforest

• rate of increase of number of tree species decreases with time

Give two reasons why an increase in the diversity of trees in the rainforest leads to an increase in animal diversity.

• Increased food sources

• Enhanced habitat diversity

Choose any one of the following statements:

• number of tree species increased rapidly at first

• the number of tree species increases more slowly later

• rate of increase of number of tree species decreases with time (ignore answers referring to numbers of trees unqualified)

• beyond about 50 years there were more tree species than in the original rainforest (allow it takes 45 to 55 years for the forest to recover (the number of species))

• there was (great) variability of number of tree species from one study area to another at the same time (ignore biodiversity increases)

What are the reasons for more/different types of food available?

• more food available (ignore more food available)

• more/different types of habitat/shelter or nest sites available (allow more/different habitats)