Science 9 · Unit 4: Maintaining life · Cambridge Lower Secondary Science Stage 9

Questions

1. 1. How does a fetus get oxygen and nutrients?

   • from the amniotic fluid only
   • by eating food in the uterus
   • by breathing through its lungs
   • from the mother's blood, through the placenta
   Check

2. 2. Which of these can cross the placenta and harm a fetus?

   • red blood cells
   • alcohol and nicotine
   • the mother's bones
   • large proteins only
   Check

3. 3. Why does smoking harm a fetus?

   • Carbon monoxide reduces the oxygen the blood carries, and nicotine narrows blood vessels.
   • Smoking gives the fetus too much oxygen.
   • Smoking makes the placenta bigger.
   • Smoke fills the fetus's lungs directly.
   Check

4. 📖 This question is about a text that students read in the app.

   4. Which of these species has the longest pregnancy?

   • chimpanzee
   • llama
   • elephant
   • moose
   Check

5. 📖 This question is about a text that students read in the app.

   5. How should you rearrange the table to see whether mass and pregnancy length are related?

   • Put the species in alphabetical order.
   • Leave them in the same order.
   • Put the pregnancy lengths in random order.
   • Put the species in order of mass, from smallest to largest.
   Check

6. 6. What is a correlation?

   • a type of graph
   • a relationship where one variable tends to change as the other changes
   • a result that does not fit the pattern
   • proof that one thing causes another
   Check

7. 📖 This question is about a text that students read in the app.

   7. Is there a correlation between a female's mass and the length of pregnancy?

   • Yes, heavier mammals usually have longer pregnancies, but there are exceptions.
   • Yes, a heavier mammal always has a longer pregnancy.
   • No, there is no pattern at all.
   • Yes, lighter mammals have longer pregnancies.
   Check

8. 📖 This question is about a text that students read in the app.

   8. A wolf and a chimpanzee both weigh 40 kg. Pregnancy lasts 64 days for the wolf and 227 days for the chimpanzee. What does this show?

   • The data must be wrong.
   • Mass decides pregnancy length exactly.
   • Wolves are heavier than chimpanzees.
   • Mass is not the only thing that affects pregnancy length.
   Check

9. 📖 This question is about a text that students read in the app.

   9. In the Swedish study, what was the mean birthweight for women with less than 100 mg of caffeine a day?

   • 3597 g
   • 3694 g
   • 3660 g
   • 3661 g
   Check

10. 📖 This question is about a text that students read in the app.

    10. When plotting the caffeine bar chart, why need the vertical axis not start at 0?

    • Bar charts never start at 0.
    • It makes the bars wider.
    • All the values are between about 3500 and 3700 g, so starting near there shows the differences.
    • Birthweights can be negative.
    Check

11. 📖 This question is about a text that students read in the app.

    11. What can you conclude from the Swedish caffeine study?

    • There is no clear effect of caffeine on birthweight.
    • More caffeine causes smaller babies.
    • More caffeine causes bigger babies.
    • Caffeine stops babies growing.
    Check

12. 12. How could the Swedish caffeine study be improved?

    • Stop measuring birthweights.
    • Measure caffeine more accurately and include many more women.
    • Only include women who drink no coffee.
    • Ask only one woman.
    Check

13. 📖 This question is about a text that students read in the app.

    13. In Japan in 2004–2005, how many babies were born in total?

    • 53 386
    • 23 713
    • 26 322
    • 2609
    Check

14. 📖 This question is about a text that students read in the app.

    14. Did most mothers smoke during pregnancy in 2004–2005?

    • No, only 2609 out of 26 322 did.
    • Yes, 23 713 did.
    Check

15. 📖 This question is about a text that students read in the app.

    15. In 2004–2005, 14.0% of babies of smokers had low birthweight, compared with 9.6% of babies of non-smokers. What does this suggest?

    • Smoking during pregnancy increases the risk of low birthweight.
    • Smoking has no effect.
    • Smoking reduces the risk of low birthweight.
    • All babies of smokers have low birthweight.
    Check

16. 📖 This question is about a text that students read in the app.

    16. Is there evidence that fewer women smoked during pregnancy in 2006–2007 than in 2004–2005?

    • Yes, fewer babies were born to smokers (2109 vs 2609) while more were born to non-smokers.
    • There is no data for 2006–2007.
    • No, more women smoked in 2006–2007.
    • No, the numbers are exactly the same.
    Check

17. 17. Do the Japanese results prove that smoking harms a fetus?

    • No, they show a correlation, but other factors could also affect birthweight.
    • Yes, they prove it completely.
    • No, smoking has no effect.
    Check