What makes a population grow or shrink

Grade 7 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Ari reads the wood duck graph and the creek's resource table. Which resource limited the pairs after year 3, and why?

   • Neither, since a flat line means no new pairs formed
   • Nest boxes, since pairs rose with boxes and stopped at 12
   • Open water, since it stayed at 6 hectares in the creek
   • Neither, since the line will keep rising after year 6
2. 2.

   Two meadow plots get the same care. Bo reads the graph and the table. Which column best explains why Plot B levels off higher?

   • Sunlight, since Plot B gets more hours
   • No column, since the plots differ by chance
   • Size, since Plot B has twice the room
   • Water, since Plot B gets more liters
3. 3.

   Esme doubled the fish food in week 5, and the count stayed at 12. What do the graph and the table show about food?

   • Food was not what limited the count
   • The fish stopped having young in week 3
   • More food should have raised the count
   • The count will rise a week or two later
4. 4.

   Jun sees that Box B was sown with twice the seeds of Box A, yet both lines level off at 24. The boxes are the same size. Why?

   • Each box's room sets the limit at 24
   • More seeds mean more plants, so Box B is wrong
   • Box B will pass Box A later
   • Box B's extra seeds made no new plants
5. 5.

   Kira sees pairs fall in the dry year 4 and return to 12 once a new pond was dug in year 5. Water stayed plentiful in year 6, yet pairs stayed at 12. Why?

   • The pairs will pass 12 once water rises more
   • The 12 boxes still set the limit
   • The line is flat, so no young were raised
   • Plentiful water stopped pairs from forming
6. 6.

   Luz sees that both meadow plots have the same room and sunlight. Plot A is watered and Plot B is not. Why does Plot B level off lower?

   • Plot B stopped making seeds in year 4
   • Plot B has less room than Plot A has
   • Plot B's water supply caps its count
   • Plot B will pass Plot A later
7. 7.

   Milo says the flat line at 16 fish means no young fish are born. The class moves extra young fish to a second tank each week. What is the flaw?

   • Young are still born; moving fish holds the count
   • A flat line shows the tank has endless room for more
   • Moving fish makes the line rise faster each week
   • The fish count should be read on the bottom axis
8. 8.

   A meadow plot has plenty of sunlight and water, but the wildflowers are crowded at 60 plants. Tala wants more plants. Which change is best?

   • Water the plot twice a day, so water is plentiful
   • Add a second plot, so seedlings get more room
   • Sow more seeds in the plot, so more plants can grow
   • Build a fence around the plot, so the line rises
9. 9.

   The tank has plenty of food and clean water, but 16 fish crowd it. Zee wants to raise the limit. Which change is best?

   • Add more fish to the tank, so the count is higher
   • Wait a few more weeks, since lines rise over time
   • Add more food, so the fish have much more to use
   • Move to a bigger tank, so fish have more room
10. 10.

    A radish box on a dim shelf has room and water, but the line levels off at 18 plants. Ren wants more plants. Which change is best?

    • Sow more seeds in the box, so the count rises
    • Move the box by a window, so plants get more light
    • Leave it, since a flat line means it is finished
    • Add water to the box each day, so water is plentiful