1.

Aerobic respiration involves conversion of glucose into pyruvate and conversion of pyruvate into carbon dioxide and water. Where do these processes occur in a eukaryotic cell? Where glucose is broken down into pyruvate A. B. C. D. Cytoplasm Cytoplasm Mitochondrion Mitochondrion Where pyruvate is broken down into carbon dioxide and water Cytoplasm Mitochondrion Cytoplasm Mitochondrion(Total 1 mark)

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2.

Which graph shows the effect of increasing carbon dioxide concentration (CO2) on the rate of photosynthesis? A.

B.

C.

2

D.

(Total 1 mark)

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3.

Which types of enzyme are found in the human digestive system? I. II. III. A. B. C. D. Amylases Proteases Lipases

I and II only I and III only II and III only I, II and III(Total 1 mark)

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4.

Which row in the table describes the first stage of cellular respiration? Substrate A. B. C. D. pyruvate pyruvate glucose glucose Location mitochondria cytoplasm mitochondria cytoplasm Product oxygen carbon dioxide pyruvate pyruvate Product water ATP water ATP(Total 1 mark)

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5.

What is the correct sequence of chemicals produced in the anaerobic respiration pathway? A. B. C. D. Lactate pyruvate ethanol Ethanol pyruvate glucose Glucose lactate pyruvate Glucose pyruvate lactate(Total 1 mark)

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6.

Why do leaves of plants look green? A. B. C. D. Most of the green light is absorbed by chlorophyll and most of the red and blue light is reflected. Most of the blue light is absorbed by chlorophyll and most of the red and green light is reflected. Most of the red light is absorbed by chlorophyll and most of the green and blue light is reflected. Most of the red and blue light is absorbed by chlorophyll and most of the green light is reflected.(Total 1 mark)

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7.

Where in eukaryotic cells is glucose broken into pyruvate, to release energy for use in the cell? A. B. C. D. Chloroplast Cytoplasm Mitochondrion Nucleus(Total 1 mark)

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8.

In the diagram of a chloroplast below where will the Calvin cycle take place?

I

III II

IV

A. B. C. D.

I II III IV(Total 1 mark)

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9.

Which limiting factor of photosynthesis is shown below?

A. B. C. D.

Increasing carbon dioxide concentration Increasing temperature Increasing light intensity Increasing humidity(Total 1 mark)

10.

Which two colours of light does chlorophyll absorb most? A. B. C. D. Red and yellow Green and blue Red and green Red and blue(Total 1 mark)

11.

The diagram below shows possible pathways for the breakdown of glucose in various cells.Glucose

Rate of photosynthesis

A Process Q (no oxygen present) B C+D Process R (oxygen present) D+E

(a)

State the names of processes Q and R.10

Q: R:

...........................................................................................................................(1)

...........................................................................................................................(1)

(b)

Deduce the names of substances A and D. A: D: ...........................................................................................................................(1)

...........................................................................................................................(1)

(c)

State the organelle in which process R takes place. .....................................................................................................................................(1) (Total 5 marks)

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12.

The graph below shows the variation in the concentration of atmospheric carbon dioxide since 1970.375 370 365 360 355 CO 2 concentration / ppm 350 345 340 335 330 325 320

1970

1975

1980

1985

1990

1995

[Source: C D Keeling and T P Whorf, Atmosphere CO2 concentrations (ppm) derived from in situ air samples, collected at Mauna Loa Observatory, Hawaii]

The annual fluctuation is mainly the result of changes in the levels of photosynthesis associated with the seasons in Northern Hemisphere forests.

(a)

(i)

Describe the overall trend shown in the graph. ........................................................................................................................... ...........................................................................................................................(1)

(ii)

Suggest a cause for the overall trend throughout the period 19701999. ........................................................................................................................... ...........................................................................................................................(1)

200012

(b)

(i)

Using a clear label, identify any one point on the graph which shows the CO2 level in mid-summer.(1)

(ii)

Explain why the concentration of CO2 varies with the seasons. ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(2)

(c)

Identify one gas, other than CO2 , which is contributing to the enhanced greenhouse effect. .....................................................................................................................................(1) (Total 6 marks)

13.

(a)

State the main photosynthetic pigment in plants. .....................................................................................................................................(1)

(b)

State the two materials used to convert carbon dioxide to organic molecules in plants. ..................................................................................................................................... .....................................................................................................................................(2)

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(c)

Explain two ways in which the rate of photosynthesis can be measured. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(4) (Total 7 marks)

14.

During photosynthesis in plants, light energy is absorbed by chlorophyll. This energy is then used to carry out photolysis, which supply substances that are needed to convert carbon dioxide into organic molecules such as glucose. (a) State the names of two products of photolysis in photosynthesis. 1. ................................................................................................................................. 2. .................................................................................................................................(2)

(b)

Explain briefly one method for measuring the rate of photosynthesis in a plant. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

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(c)

The rate of photosynthesis is affected by light intensity. Draw a line on the graph below to show the relationship between light intensity and the rate of photosynthesis.

rate of photosynthesis

light intensity(2)

(d)

State two factors in the environment of a plant, apart from light intensity, that can affect the rate of photosynthesis in the plant. 1. ................................................................................................................................. 2. .................................................................................................................................(2) (Total 8 marks)

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15.

Explain the effect of substrate concentration on enzyme activity. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 3 marks)

16.

The graph below shows the effect of light intensity on photosynthesis at 0.1% carbon dioxide concentration.

Rate of photosynthesis / arbitrary units

Light intensity / arbitrary units(a) On the graph above, draw the results obtained at 0.01% carbon dioxide.(1)

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(b)

Outline the fate of the oxygen and hydrogen which are produced in the photolysis of water during photosynthesis. Oxygen: ............................................................................................................... ............................................................................................................... Hydrogen ............................................................................................................... ...............................................................................................................(2)

(c)

The energy produced in photosynthesis can enter a food chain. Explain how this energy can be lost before it reaches the last link in the chain. .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................(2) (Total 5 marks)

17.

Explain the similarities and differences in anaerobic and aerobic cellular respiration.(Total 8 marks)

18.

Up to two additional marks are available for the construction of your answers.(2)

(a) (b) (c)

Draw and label a diagram of the digestive system.(4)

Discuss factors that affect enzyme activity.(9)

Outline one industrial use of lactose.(5) (Total 20 marks)

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