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?

   • Open water, since it stayed at 6 hectares in the creek
   • Neither, since the line will keep rising after year 6
   • Nest boxes, since pairs rose with boxes and stopped at 12
   • Neither, since a flat line means no new pairs formed
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
   • Size, since Plot B has twice the room
   • No column, since the plots differ by chance
   • 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?

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

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

   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 has less room than Plot A has
   • Plot B will pass Plot A later
   • Plot B's water supply caps its count
   • Plot B stopped making seeds in year 4
6. 6.

   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?

   • A flat line shows the tank has endless room for more
   • The fish count should be read on the bottom axis
   • Young are still born; moving fish holds the count
   • Moving fish makes the line rise faster each week
7. 7.

   Pia says the line rose after the nest boxes were added in year 2, so water must have caused the rise. What is the flaw?

   • The marked change was boxes, so boxes explain the rise
   • The line will keep rising, so the boxes do not matter
   • Neither one matters, since counts rise by pure luck
   • Water is a resource, so it matters more than boxes
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
   • Build a fence around the plot, so the line rises
   • Sow more seeds in the plot, so more plants can grow
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?

   • 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
   • Add more fish to the tank, so the count is higher
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?

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