What makes a population grow or shrink

Grade 7 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Bo reads a graph of duckweed floating on a pond. What percent of the pond surface did the duckweed cover in year 4?

   • 25 percent
   • 50 percent
   • 4 percent
   • 80 percent
2. 2.

   Esme reads a graph from a park where nest boxes were added in year 3. How many bluebird pairs nested in year 4?

   • 10 pairs
   • 4 pairs
   • 6 pairs
   • 12 pairs
3. 3.

   Jun's class grows beans in one small box with plenty of sun and water. The line levels off at 30 plants and the leaves touch. Which resource ran short?

   • Shelter from rain
   • Space to grow
   • Nesting spots
   • The number of weeks
4. 4.

   The park has 8 nest boxes, plenty of water and plenty of food. Kira sees the line level off at 8 pairs. Which resource ran short?

   • Nesting spots
   • Food for the pairs
   • Drinking water
   • The calendar year
5. 5.

   Luz sees the sunflower line fall in year 4, a dry year. The field is big and sunny. Which resource ran short?

   • The number of years
   • Space
   • Water
   • Sunlight
6. 6.

   A garden bed has plenty of room. Noah reads the line for bean plants. Which sentence describes how the count grows?

   • It stays the same, then falls
   • It grows faster each week
   • It grows by the same amount each week
   • It levels off after the first week
7. 7.

   Pia compares two sunflower fields. Which field's line shows that resources are starting to run short?

   • Field B: its line levels off
   • Field A: its line keeps rising
   • Both: the lines start the same
   • Field A: its line reaches the top
8. 8.

   Ren reads that duckweed covers 90 percent of the pond in years 5, 6 and 7. What does the flat part of the line show?

   • Plants added are about equal to plants lost
   • No new plants are being made
   • The pond is growing faster now
   • The count was skipped those years
9. 9.

   The line for bluebird pairs is flat in years 4, 5 and 6. Tala says nothing happens in those years. What is right?

   • Young are still raised, but the count stays steady
   • No young are raised in those years
   • The nest boxes were taken away
   • The pairs moved to a new park
10. 10.

    Zee sees the sunflower line flat at 120 plants in years 3 to 6. What is true about the number of plants in those years?

    • It is 3 plants, then 4, 5 and 6
    • It keeps rising a little each year
    • It stays about the same from year to year
    • No new plants sprout in those years