How people affect biodiversity

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Direct drivers of change in nature, ranked by global impact so far (real data, IPBES 2019)

   rank	driver
   1	changes in land and sea use
   2	direct exploitation of organisms
   3	climate change
   4	pollution
   5	invasive alien species

2. 1.

   Bo reads the ranking. Which statement does the table support?

   • Climate change has had the largest global impact so far, since its warming reaches the whole planet
   • Invasive alien species rank first, since they spread the fastest
   • Land and sea use changes have had the largest global impact so far; climate change ranks third
   • The top driver explains the loss, so drivers 2 to 5 can be set aside

3. Two NOAA lists at the end of 2023 (real data, NOAA Fisheries, 2023)

   list	what puts a stock on it	stocks
   overfishing list	the catch rate is too high	21
   overfished list	the population is too small	47

4. 2.

   Esme reads the NOAA table. Which sentence matches it?

   • Overfishing means the stock is too small, and overfished means the catch is too high
   • A stock can be too small, overfished, or caught too fast, subject to overfishing
   • The two lists name the same 21 stocks, counted twice
   • An overfished stock is gone, so 47 stocks have disappeared

5. DDT after the 1972 cancellation (real facts, US EPA)

   when	what the EPA states
   1972	the EPA issued a cancellation order for DDT because of its effects on wildlife
   after US use stopped	levels in the environment and in animals have gone down
   still today	residues from past use remain, because DDT lasts a long time in the environment

6. 3.

   Kira reads the card about DDT. What does it say happened after DDT use stopped in the United States?

   • Levels went down, but residues from past use remain
   • Residues were gone, because the soil and water looked clean
   • Levels fell to 0 as soon as the order was issued
   • Levels went up, because DDT lasts a long time

7. Tests at four sites on a model stream (model data)

   site	water looks	pesticide level (parts per billion)	limit (parts per billion)
   site 1	clear	2	5
   site 2	cloudy	0	5
   site 3	clear	9	5
   site 4	cloudy	4	5

8. 4.

   Luz reads the table. Which sites go over the pesticide limit?

   • Sites 1 and 3: clear water hides pollution, so both are over
   • Sites 2 and 4: cloudy water shows the pollution
   • Only site 3: 9 is above the limit of 5, though the water looks clear
   • Site 4: 4 is the highest reading among the cloudy sites
9. 5.

   Milo reads the graph. By year 4, what share of patch B's original species was lost?

   • 68%: the 34 species that were left
   • 32%: 16 of 50 species
   • 34%: the 34 species left
   • 16%: the 16 species lost
10. 6.

    Noah reads the graph. About how far uphill did the highest plant move each decade, and what fits the pattern?

    • About 160 m a decade, the whole rise counted as if it happened in one decade
    • No shift, since the plant stayed near 800 m
    • About 40 m a decade, fitting a range that shifts upslope as the air warms
    • About 4 m a decade, the rise each year
11. 7.

    Pia reads the graph. What does it show about the pesticide level after the ban?

    • It reached 0 as soon as the ban began
    • It fell by the same amount each year
    • It halved every 2 years and was still above 0 at year 8
    • It fell by 4 every 2 years and reached 0 by year 8

12. The zebra mussel (real data, USGS Nonindigenous Aquatic Species)

    fact	entry
    native range	Black, Caspian and Azov Seas
    likely route to the Great Lakes	a cargo ship's ballast water
    found today in	all of the Great Lakes

13. 8.

    Ren reads the zebra mussel card. Which statement is supported?

    • It is native to the Black, Caspian and Azov Seas and is invasive in the Great Lakes
    • It is invasive in the Black Sea, since it arrived there from the Great Lakes by ship
    • It is native to the Great Lakes, since it is found in each of them today
    • It is native to ships' ballast water, which carried it to the lakes

14. Kudzu in the United States (real data, from OpenStax Biology 2e)

    fact	entry
    native to	Japan
    brought to the United States	1876
    later use	planted to protect soil
    area covered in the southeast	over 7 million acres

15. 9.

    Tala reads the kudzu card. Kudzu was planted on purpose to protect soil. Why is it called invasive?

    • It is native to the southeast, where it covers over 7 million acres
    • It is native to Japan and now spreads over more than 7 million acres of the southeast
    • It was brought in 1876, which is too long ago to be called invasive
    • A species counts as invasive if it arrives by accident, and kudzu was planted on purpose

16. Cane toads in Australia (real data, Australian Museum)

    fact	entry
    toads brought from Hawaii	about 100
    toads released in north Queensland in July 1935	more than 3,000
    reason for the release	to control cane beetles
    range since then	much of northern Australia

17. 10.

    Zee reads the cane toad card. Which statement does the card support?

    • More than 3,000 toads were brought from Hawaii in 1935
    • The release controlled the beetles, so the toads stayed in the cane fields
    • About 100 toads became 3,000 released in 1935, and the range now covers much of the north
    • Cane toads are native to northern Australia, which is why they live across so much of it today