Which of the following points supports the theory that mitochondria and chloroplasts were once free-living prokaryotes? Select all correct choices.

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7.3 Explain why the pressure of the blood returning to the fish heart is lower than the pressure of the blood returning to the human heart. (2)

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9.5 Four solutions were tested to see whether they contained protein, starch or glucose. The colours of the solutions after the tests are recorded in the table. Which solution contained protein and glucose but not starch? (1)   biuret test iodine test Benedicts’s test A blue brown orange B blue blue-black blue C purple brown orange D purple blue-black blue    

  TOTAL QUESTION 6 

3 The human kidney removes urea from the blood.   3.1  Name two other substances the kidney removes from the blood. (2)

QUESTION 7  

  TOTAL QUESTION 8

4.2 Reflexes in animals and phototropism in plants are both responses to stimuli.   4.2.1 Give two similarities between the mechanisms involved in each response (2)