Whales and dolphins

Whales and dolphins

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about using a classification key to classify animals.
The whales and dolphins drawn below have been drawn to scale, that is 1 cm = 2 m. Note that animal D has been enlarged as well.
 
 
 
 
 
 
Which group are they in?
 
a)
Look carefully at the pictures of whales and dolphins and tick the boxes to show which have teeth and which have baleen plates. Get your teacher to check your groups before you answer part b).
 
    Teeth Baleen plates
i) A
ii) B
iii) C
iv) D
v) E
vi) F
 
b)
 
Next divide each of the groups from a) into the smaller groups i) to iv) in the key below.
On the key fill in the boxes with the letter of the whale or dolphin that matches. 
 
 
Key to some whales and dolphins
 
 
c)
Tick the box(es) to show which larger group(s) whales and dolphins belong to.
 
 
Fish    
Vertebrates    
Mammals    
Invertebrates    
Cold-blooded animals
    
Task administration: 

This task was trialled without telling students what a baleen plate is. You may wish to tell students this before the task is attempted.
Animals:
A = Blue Whale
B = Right Whale
C = Orca or Killer Whale
D = Bottlenose Dolphin
E = Sperm Whale
F = Humpback Whale

Level:
4
Curriculum info: 
Science, Communicating in science, Living World
Keywords: 
evolution, classification, whales, dolphins, classification keys, keys
Description of task: 
Task: Students classify each of six drawn whales as either toothed or baleen whales. They then divide each group further by using a key. Assessment focus: Interpreting information.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Interpret representations
This resource provides opportunities to discuss
  • the purposes of identification keys and how to read them.
  • the role of scale in science diagrams.
 

 
Science capabilities: 
Interpret representations
Making Better Sense: 
Whales
Answers/responses: 
  Y9 (04/2005)
a)  
i)
ii)
iii)
iv)
v)
vi)		  
very easy
very easy
very easy
very easy
very easy
very easy
b) i)
ii)
iii)
iv)		 B
A, F
E
C, D		 moderate
moderate
easy
moderate
c)   Ticks in vertebrates and mammals boxes only. (Correct answer)
Tick in mammal box only (partially correct answer)		 very difficult
difficult
Diagnostic and formative information: 

Students were able to easily identify from pictures whether different species of whales and dolphins had teeth or baleen plates. Dividing these large groups into smaller groups by using a key with written descriptions was a more difficult task. If students are finding this task difficult it may be useful to check whether the problem is being caused by the vocabulary involved or whether it is the key itself. In either case it could be an opportunity to discuss the "nature of science" idea that science has its own special language and ways of presenting information.

In question c) students were asked to identify which groups whales and dolphins belong to. Nearly one third of the trial group of 175 students did not appear to recognise that if whales and dolphins belonged to some specific groups there were other groups they could not possibly belong to. For instance if they belonged to the group of mammals they could not possibly belong to the group of fish. This would suggest that further work on classification may be useful. Again this would be an opportunity to promote a "nature of science" idea:

  • Science has its own special ways of grouping things. There are some big groups that can be divided into smaller groups eg., vertebrates can be divided into mammals, birds, fish, reptiles but no animal can be a mammal and a bird.