Carrying capacity: J-shaped and S-shaped growth

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Bo reads the graph. Which words describe the shape of the line?

   • Straight: the same number is added each hour
   • Falling: the number gets smaller each hour
   • S-shaped: it speeds up, then levels off
   • J-shaped: it climbs faster and faster to the end
2. 2.

   Esme reads the graph. Room and food stay plentiful for one group. Which line fits that group?

   • Line B, because it levels off, which shows room and food are plentiful
   • Line B, because it has more plants on day 3, 29 against 16
   • Neither line, because plentiful food gives a flat line
   • Line A, because it is J-shaped
3. 3.

   Jun reads the graph. What is the carrying capacity of the pond?

   • 80 frogs
   • 6 frogs
   • 60 frogs
   • 7 frogs

4. Read this first

   Snails in a garden tank (model data)

   week	snails
   0	4
   1	9
   2	17
   3	28
   4	38
   5	44
   6	48
   7	49
   8	50

5. 4.

   Luz reads the table. About what carrying capacity does the tank show?

   • 50 snails
   • 100 snails
   • 4 snails
   • 8 snails

6. Bacteria in a flask with plenty of food (model data)

   hour	bacteria
   0	50
   1	100
   2	200
   3	?

7. 5.

   Ren reads the table. The count doubles each hour. How many bacteria are there at hour 3?

   • 800 bacteria
   • 300 bacteria
   • 600 bacteria
   • 400 bacteria

8. Duckweed on a pond (model data)

   day	plants
   0	4
   1	8
   2	16
   3	32

9. 6.

   Tala reads the table. How many plants were added between day 2 and day 3?

   • 4 plants
   • 8 plants
   • 32 plants
   • 16 plants

10. Three groups of bacteria (model data)

    group	day 0	day 1	day 2	day 3
    A	10	20	30	40
    B	10	20	40	80
    C	10	30	90	270

11. 7.

    Zee reads the table. Which group doubles each day?

    • Group A, because it goes up by 10 a day
    • Group C, because it triples, 30 to 90 to 270
    • Group A and Group B, because both have 20 on day 1
    • Group B, because 20, 40 and 80 each double
12. 8.

    Milo reads the graph. Why does the line flatten near the carrying capacity?

    • Space and light get short as the plants crowd, so growth slows
    • The plants stop growing once they are old
    • Nothing limits the plants, so the flat part is a graph slip
    • Duckweed has a fixed limit of 100 on any pond

13. Yeast in a test tube with a fixed amount of sugar (model data)

    hour	yeast cells (thousands)	sugar left (grams)
    0	4	100
    1	10	85
    2	22	60
    3	34	25
    4	38	8
    5	38	2

14. 9.

    Noah reads the table. What change in the table explains why the yeast count levels off?

    • The yeast count rises from 4 to 38, so the sugar grows too
    • The sugar left falls from 100 to 2 grams, so the yeast run low on food
    • Yeast settle at 38 thousand cells in any test tube
    • The sugar left stays high, so food is not short
15. 10.

    Kira reads the graph. In weeks 0 to 3 the line climbs a bit more each week. Why?

    • Each week the same number of seedlings is added
    • The seedlings are already at the carrying capacity
    • The count is nearest its limit, so growth is fastest
    • Few seedlings share plenty of room and light, so growth is almost J-shaped