Characteristics of living thingsIB MYP Biology: Subtopic test

1. 1
   A class in Wellington watches a candle burn. The flame gets bigger when more wax melts, it uses oxygen from the air, it releases carbon dioxide and heat, and it flickers and moves in the draught. A student suggests that the candle must be alive.

   (a)

   Which life process releases energy from glucose in the cells of a living organism?

   [1 mark]

   • ARespiration
   • BExcretion
   • CMovement
   • DSensitivity

   (b)

   Which term describes the removal of waste products made by the chemical reactions inside an organism?

   [1 mark]

   • ASensitivity
   • BEgestion
   • CExcretion
   • DGrowth

   (c)

   Explain why the burning candle is not a living thing.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student in Vancouver grows bean seedlings on a windowsill. Over two weeks the shoots bend towards the window and the plants grow from 5 cm to 12 cm tall. The dry mass of the plants increases. The student also notes that the plants make their own food using light.

   (a)

   Which life process is shown when the bean plants make their own food using light?

   [1 mark]

   • ARespiration
   • BNutrition
   • CExcretion
   • DReproduction

   (b)

   Which life process is shown when the bean plants increase from 5 cm to 12 cm tall and gain dry mass?

   [1 mark]

   • AMovement
   • BExcretion
   • CSensitivity
   • DGrowth

   (c)

   Outline how a bean plant shows sensitivity and how it carries out reproduction.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A scientist is given three samples from a field station: a dry seed that has been stored in a jar for 20 years and shows no obvious movement or growth, a flask of yeast and sugar solution that is bubbling, and an iron nail that is covered in orange rust.

   (a)

   Describe three pieces of evidence that could show that the yeast is living, naming the life process for each.

   [3 marks]

   (b)

   Explain why the rusting nail is not living, but the seed is living even though it shows no signs of life.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A space agency sends a rover to Mars to test the soil for signs of life. In one test, the rover adds a sugar solution to a soil sample and measures the carbon dioxide released in 24 hours. Untreated soil released 40 units of carbon dioxide. A second sample of the same soil, heated to 160 degrees Celsius to kill any living organisms, released 38 units. The agency's mission costs several billion dollars.

   (a)

   Evaluate whether the results show that there are living organisms in the Martian soil, and suggest how the rover could improve the investigation.

   [6 marks]

   (b)

   Discuss the benefits and drawbacks of spending large amounts of money on searching for life on other planets, and justify whether the mission is worthwhile.

   [6 marks]

   Total for question 4: 12 marks

End of questions