MERRYLAND INTERNATONAL SCHOOL

DEPARTMENT OF BIOLOGY- GRADE 9

PAST PAPER PRACTICE

1. Fig. 1.1 shows some cells from the shoot tip of an onion, Allium cepa.

Fig 1.1

(i) Cell A is dividing by mitosis.

State the role of mitosis and meiosis in organsms.

mitosis meiosis
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………………………………………………………………………………………………………………......[2]

2. A student carries out an investigation of the growth of a plant shoot by auxins. Light is shone onto

only one side of the shoot for three days. Fig.2.1 shows the results.

Fig 2.2
(a) (i) On diagram B in Fig. 2.1, shade the area of the shoot that would contain the greatest
concentration of auxins. [1]
(ii) State the name of the response shown by the shoot in diagram B in Fig. 2.1.
positive phototropism
.....................................................................................................................................................[1]
(b) Describe how auxins cause the shoot to bend.
Auxins are produced in the shoot tip. They move away from the light or diffuse
.................................................................................................................................................................
to the darker side. Auxins stimulate cell elongation of the shoot tip resulting in
.................................................................................................................................................................
the bending of shoot towards light.
.............................................................................................................................................................[2]

(c) Describe the advantage to the plant of the response shown in Fig 2.1.
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explain photosynthesis/ pollination
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.............................................................................................................................................................[2]
(d) The student repeats the investigation with the shoot shown in Fig. 2.2.

Fig 2.2

(e) Predict and explain the results observed after five days.
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No growth of shoot as shoot tip is removed. Auxins are produced in the shoot
................................................................................................................................................................. tip.
.............................................................................................................................................................[2]
3. A scientist carried out an investigation to find out which concentration of the pectinase solution
gave the maximum volume of juice.
(i) Identify the variable that was changed (independent variable) by the scientist in this investigation.
concentration of pectinase solution
........................................................................................................................................................ [1]
(ii) Identify the controlled variable in this investigation.
pH of the solution
………………………………………………………………………………………………………………[1]
The results from this investigation are shown in Table 2.1.
3.1
 Table 2.1
3.

7.7
14.7

Calculate the mean value for percentage concentration of pectinase solution 5.0 and 7.5.
2.5
Complete the missing mean in the table 2.1.
4. [2]
4. Pineapple plants are adapted to grow in hot dry conditions.
Scientists investigated the number of stomata open, in pineapple plants, at different times of day.
The data is shown in Table 2.2 (00:00 is midnight).

4.1
 4.1
(ii) Plot a bar chart on the grid to show the data in Table 2.2.