Download Worksheet 1 - School

B2b: 7 (1)
Removing waste: the basics
1 Use these words to label the diagram below.
bladder kidney liver lung urethra
2 Complete this table by writing in a function for each organ or structure:
Organ/structure
Bladder
Kidney
Liver
Lung
Urethra
Function
B2b: 7 (2)
Removing waste: pie charts
One pie chart shows the composition of the air we breathe in and the other shows air that we
breathe out (percentages are approximations). Study them carefully and answer the questions
below.
1 How much nitrogen is found in the air around us?
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2 Which sample is exhaled air? How can you tell?
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3 Explain why the amount of oxygen in the two samples is different.
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4 Describe how urea is made.
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B2b: 7
Answers to Worksheets
Worksheet B2b: 7 (1)
1 Labels from top to bottom of diagram: lung; liver; kidney; bladder; urethra.
2
Organ/structure
Function
Bladder
Stores urine
Kidney
Filters blood
Liver
Removes toxins
Lung
Gas exchange
Urethra
Urine passes out of the body by this tube
Worksheet B2b: 7 (2)
1 78%
2 Sample A because it has only 16% oxygen but 4% carbon dioxide.
3 The body uses oxygen during respiration so sample B has more oxygen than sample A.
4 The nitrogen part of an amino acid molecule is removed, this will go to making ammonia which
is then converted into urea.
B2b: 7
Technician’s Notes
Resources required for the lesson:
 Whiteboard and pens
 Model of human torso showing liver and kidneys
 Paper and pens