Cambridge IGCSE Biology - 0610 - Supplement Paper 4 2010 Winter Zone 1

(a) (i) Name the parts labelled A to C shown in Figs. 1.1 and 1.2.
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(a) (ii) Describe what happens to the structures shown in Figs. 1.1 and 1.2 to bring about fertilisation. You may refer to the structures labelled A to C by their letters if you wish.
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(a) (iii) Explain the advantages and disadvantages of self-pollination for flowering plants, such as soybean.
advantages
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disadvantages
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(b) (i) Name the genus to which the soybean belongs.
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(b) (ii) State two features which are only found in dicotyledonous plants.
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The human menstrual cycle is controlled by four hormones. Fig. 2.1 is a diagram that shows the site of production and the target organs of these hormones.

(a)

(i) Name hormones X and Y.     [2]

(ii) Name organ Z. [1]

(b) Describe the roles of progesterone during the menstrual cycle and during pregnancy.  [3]

(c) Many medical experts agree that breast-feeding of babies is better than bottle-feeding using formula milk.

State two advantages and one disadvantage of breast-feeding. [3]

(a) Define the term \textit{aerobic respiration}.
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During exercise the movement of the ribcage enables air to enter the lungs.
(b) Describe how the ribcage is moved during inspiration (breathing in) and explain how this causes air to enter the lungs.
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(c) Explain how the ribcage returns to its resting position during expiration (breathing out).
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Some students carried out an investigation on a 16-year old athlete. Table 3.1 shows the results of their investigation on the athlete’s breathing at rest and immediately after 20 minutes of running.
Ventilation rate is the volume of air taken into the lungs per minute.

[Table_1]
\begin{center} \begin{tabular}{|c|c|c|} \hline & \textbf{at rest} & \textbf{immediately after 20 minutes of running} \\ \hline rate of breathing / breaths per minute & 12 & 20 \\ \hline average volume of air taken in with each breath / dm$^3$ & 0.5 & 3.5 \\ \hline ventilation rate / dm$^3$ per minute & 6.0 & \text{………..} \\ \hline \end{tabular} \end{center}

(d)\ (i) Calculate the ventilation rate of the athlete immediately after 20 minutes of running.
Write your answer in Table 3.1. [1]

(ii) Explain why the athlete has a high ventilation rate \textit{after the exercise has finished}.
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(a) Suggest how lymph is moved in the lymph vessels.

(b) After a meal rich in fatty foods, the lymph leaving the ileum is full of fat droplets.

Explain why there are fat droplets in the lymph leaving the ileum.

(c) Lymph flows through lymph nodes. Fig. 4.2 shows the action of white blood cells in a lymph node when bacteria are present.

(i) Name the type of nuclear division shown at P in Fig. 4.2. [1]

(ii) Name the molecules labelled Q in Fig. 4.2.
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(iii) Describe how bacteria are destroyed by cell R.
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(d) Describe the results shown in Fig. 4.3. Credit will be given for using figures from Fig. 4.3 to support your answer.

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(e) Many different antibiotics are used.
Suggest why some antibiotics are used less frequently than others.
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Marine conservationists are concerned that fish stocks in the sea are decreasing. Drastic measures will have to be taken to stop the extinction of many fish species.
Fig. 5.1 shows a marine food web. Tuna are large carnivorous fish that are an important human food. Dolphins may be caught in fishermen’s nets and die. [Image_1: Marine food web diagram]
(a) State the names given to trophic levels 1 and 3.
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3 ......................................................................................................... [2]
(b) Explain why it is more energy efficient for humans to eat herbivorous fish rather than tuna.
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(c) Explain why it is necessary to conserve animals, such as tuna and dolphins, which are at trophic level 4.
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(d) Many seas are polluted by non-biodegradable plastics.
Suggest the likely effects of this pollutant on the marine environment.
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(a) Sketch a line on Fig. 6.1 to show the population of Daphnia from March to the end of November 2007. [3]

(b) Suggest why there were very few Daphnia present in the lake in 2006. [2]
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(c) Explain the changes in the population of Daphnia in 2007. [4]
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Seeds of the mung bean, Phaseolus aureus, were germinated and grown in a dish for a few days in the dark. The dish was then placed as shown in Fig. 7.1 A.
Fig. 7.1 B shows the seedlings after a further two days in the dark.

(a) Name the response shown by the roots in Fig. 7.1.
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(b) Suggest why the seedlings were kept in the dark during this investigation.
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(c) Explain why it is important for their early growth that the roots and shoots of seedlings respond in the way shown in Fig. 7.1B.
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(d) The response shown by the shoots in Fig. 7.1B is coordinated by auxins.
Explain how auxins bring about this growth response in shoots.
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(e) Weed seedlings are sprayed with synthetic auxins to kill them.
Suggest how these weedkillers spread throughout the plant.
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