Question 4

 

(a) What type of variation is tongue rolling?                                                       [1 mark]
      (b) Give two other examples each of the type of variation stated in 4 (a) which occur in:
            (i) plants;
            (ii) animals.                                                                                          [4 marks]

(c) The heights of twenty-two students in a school are measured in cm. The results were recorded as shown below:

150   127         123      131      101      122      132      117      132      134      101

124   115         105      143      114      104      150      100      146      153      140     

 

1. Complete the frequency table below.

 

Height (cm)	Frequency
100-109
110-119
120-129
130-139
140-149
150-159

 

 

 

                                                                        [5 marks]

 

 

 

 

 

 

(ii) On the graph sheet provided, draw a histogram of the frequency distribution using a scale of 1cm to 10 units on the x-axis and 1cm to 1 unit on the y-axis.                  [10 marks]

Some candidates could state the type of variation that tongue-rolling is, although some could not spell the term properly.

 

Some candidates stated examples of morphological variation for plants and animals since they had missed the naming of the type tongue rolling is;

 

Some candidates were able to complete the frequency table and draw the histogram perfectly but some candidates could not use the specified scale.

 

The expected answers are:

 

(a) Types of variation

Physiological/discontinuous.                                                                         

 

(b) Other examples

(i) in plants

• taste of fruits;
• resistance to diseases;
• resistance to pests;
• food contents of fruits;
• shape of seeds/fruits;
• colour of flowers;
• position of flowers/fruits.                                                                         

 

(ii) in animals

• behaviour pattern;
• ability to taste PTC;
• hand clasping;
• ear lobe;
• blood group;
• genotype;
• fingerprint;
• Rhesus factor;
• sex                 

 

 

(c) (i)   Frequency table

 

Height (cm)	Frequency
100-109	5
110-119	3
120-129	4
130-139	4
140-149	3
150-159	3

 

 

 

 

 

 

 

 

 

 

Any 5 x 1 [5 marks]

(ii)    Histogram

Title (Tl)    
A histogram showing the frequency distribution of heights

 

Details (D)
Same width for size of bar (Sb)                                             
No space between bars (Ns)  

                                               

Quality (Q)
Scale (Sc):      

1cm to 10 units on the x-axis 
1cm to 1 unit on the y-axis                            
Accuracy of histogram bars (Ahb)                                       
Label of axes (La)