Science 9 · Unit 7: Genes and inheritance · Cambridge Lower Secondary Science Stage 9

Questions

1. 1. Which is the correct order for natural selection?

   • genes passed on → survival → variation → reproduction
   • variation → survival of the best adapted → reproduction → genes passed on
   • survival → variation → genes passed on → reproduction
   • reproduction → variation → genes passed on → survival
   Check

2. 2. Why do doctors advise using antibiotics only when they are really needed?

   • Antibiotics make people taller.
   • Antibiotics kill viruses.
   • Using them often helps resistant bacteria survive and spread.
   • Antibiotics never work.
   Check

3. 3. Which part of a lizard's cells contains genes?

   • the cell membrane
   • the cell wall
   • the nucleus
   • the cytoplasm
   Check

4. 4. What is the word for passing on genes from parents to offspring?

   • inheritance
   • variation
   • DNA
   Check

5. 5. Why does a lizard's tail fall off when it is attacked?

   • The squirming tail distracts the predator while the lizard escapes.
   • The predator pulls it off on purpose.
   • The tail is too heavy.
   • The lizard is ill.
   Check

6. 6. Snakes are especially good at seeing blue. Why are brown-tailed lizards more likely to be eaten?

   • Snakes notice the blue tail and attack it, but attack a brown-tailed lizard's body.
   • Brown lizards are slower.
   • Brown lizards taste better.
   • Blue lizards are poisonous.
   Check

7. 7. In the next generation, more lizards have blue tails. What is the correct explanation?

   • More blue-tailed parents survive to reproduce and pass on their genes for blue tails.
   • The lizards change their tail colour so they won't be eaten.
   • The lizards learn that blue tails are safer.
   Check

8. 8. Sofia and Zara test whether green pasta "caterpillars" are harder to find on grass than yellow ones. What should they record?

   • the time Marcus takes to find 20
   • the weather that day
   • how many green and how many yellow caterpillars Marcus picks up
   • which hand Marcus uses
   Check

9. 9. Why did the girls use 50 green and 50 yellow caterpillars?

   • so Marcus would find only green ones
   • because 100 is a round number
   • so both colours had an equal chance of being found
   • because green pasta is cheaper
   Check

10. 10. How can the girls make their results more reliable?

    • Repeat the experiment five times with the same caterpillars, with different students collecting.
    • Repeat with 25 green and 75 yellow caterpillars.
    • Repeat with 50 blue and 50 red caterpillars.
    Check

11. 11. In natural selection, which comes first for the caterpillars?

    • More green caterpillars hatch out of the eggs.
    • The fertilised eggs are more likely to contain genes for green caterpillars.
    • The adult moths mate and lay fertilised eggs.
    • Green caterpillars are more likely to survive and grow up into adult moths.
    Check

12. 12. Green caterpillars are more likely to survive and grow up into adult moths. Which sentence comes next?

    • The fertilised eggs are more likely to contain genes for producing green caterpillars.
    • The caterpillars change colour to green so they will not be eaten.
    • So adult moths are more likely to contain genes for producing green caterpillars than for producing yellow caterpillars.
    • So more green caterpillars hatch out of the eggs than yellow caterpillars.
    Check

13. 13. The adult moths mate and lay fertilised eggs. Which sentence comes next?

    • Green caterpillars are more likely to survive and grow up into adult moths.
    • So adult moths are more likely to contain genes for producing green caterpillars.
    • The adult moths learn that green is safer.
    • The fertilised eggs are more likely to contain genes for producing green caterpillars than for producing yellow caterpillars.
    Check

14. 14. Which comes last in the caterpillar natural selection story?

    • Green caterpillars are more likely to survive.
    • More green caterpillars hatch out of the eggs than yellow ones.
    • Adult moths are more likely to have genes for green caterpillars.
    • The adult moths mate and lay fertilised eggs.
    Check

15. 15. How did woolly mammoths develop from steppe mammoths as the climate got colder?

    • Those with thicker fur survived the cold better and passed on genes for thick fur.
    • Each mammoth grew thicker fur because it was cold.
    • Mammoths learned to grow fur.
    • Steppe mammoths ate woolly plants.
    Check

16. 16. Why might long tusks have helped woolly mammoths survive?

    • They made them lighter.
    • They could clear snow to find plants to eat.
    • They helped them swim.
    • They kept them warm.
    Check