What makes a population grow or shrink

Grade 7 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

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

   • No column, since the plots differ by chance
   • Water, since Plot B gets more liters
   • Sunlight, since Plot B gets more hours
   • Size, since Plot B has twice the room
2. 2.

   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
   • More food should have raised the count
   • The count will rise a week or two later
   • The fish stopped having young in week 3
3. 3.

   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
4. 4.

   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 line is flat, so no young were raised
   • Plentiful water stopped pairs from forming
   • The 12 boxes still set the limit
   • The pairs will pass 12 once water rises more
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 will pass Plot A later
   • Plot B has less room than Plot A has
   • Plot B stopped making seeds in year 4
   • Plot B's water supply caps its count
6. 6.

   Noah says the line shows the box will hold 100 radish plants by week 8. The box has room for about 30 plants. What is the flaw?

   • The weeks should be read on the side axis
   • Growth stops at 28 because births stop there
   • There is no flaw, since the line keeps rising each week
   • Growth slows as room fills and levels off near 30
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?

   • Water is a resource, so it matters more than boxes
   • 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
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?

   • Add a second plot, so seedlings get more room
   • Water the plot twice a day, so water is plentiful
   • 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?

    • 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
    • Sow more seeds in the box, so the count rises