How living in groups helps animals survive

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Two minnow schools (model data)

   school	minnows	visits a day	minnows lost per visit
   school X	10	2	1
   school Y	40	2	1

2. 1.

   Ari reads the model card. Each visit takes one minnow, picked at random. Which statement compares one minnow's chance of being lost in a day?

   • The same in both: each school loses 2 minnows a day
   • Higher in school Y: 40 minnows make a bigger target for each visit
   • Lower in school Y, since a bigger school finds more food
   • Lower in school Y: 2 of 40 is 5%, against 2 of 10, or 20%, in school X

3. Flocks of different sizes (model data)

   flock size	seconds one bird scans per minute	seconds until the flock spots a threat
   1	40	12
   4	30	6
   16	20	3

4. 2.

   Bo reads model data on flocks. Which statement does the table support?

   • Flock size changes how much food the birds find, not the scanning
   • Each bird scans less in a bigger flock, yet the flock spots a threat sooner
   • A bigger flock spots a threat later, since each bird scans fewer seconds in a minute
   • Each bird scans more in a bigger flock, since more birds share the work

5. Nesting colonies (model data)

   nests in the colony	nests with parasites (%)
   10	20
   50	40
   100	60

6. 3.

   Esme reads model data on nesting colonies. Which cost of a larger colony does the table show?

   • Fewer nests have parasites: 60% in a colony of 10 and 20% in a colony of 100
   • More nests have parasites: 20% in a colony of 10 and 60% in a colony of 100
   • No cost: a bigger colony helps, since more adults can watch the nests
   • Less food for each nest, which the parasite column shows
7. 4.

   Jun reads the graph. During which days did the alone minnows fall fastest, and by how many?

   • Days 0 to 1: the alone line falls from 20 to 16, a loss of 4 minnows
   • Days 1 to 2: the alone line falls from 16 to 13, a loss of 3 minnows
   • Days 5 to 6: the alone line ends at 9, its lowest point
   • Days 0 to 1: the school line falls from 20 to 19, a loss of 1 minnow
8. 5.

   Luz reads the model graph of huddled birds that touch their neighbors. A bird alone loses 100 units. Which reason best fits the graph?

   • The birds in the middle save heat; the edge birds still lose 100 units
   • Huddling helps the birds find food, so they lose less heat
   • Each bird makes more heat when more birds crowd in, so the loss keeps falling at the same rate
   • Touching birds expose less body surface to the cold, and each added bird saves less

9. Waggle dance card (model data)

   dance	waggle run (s)	angle clockwise from vertical (°)	sun's compass bearing (°)
   dance 1	2.0	40	180

10. 6.

    Milo uses the model rule: bearing to the resource = sun's bearing + dance angle; 1 s of run = 400 m. Where do nestmates fly?

    • Bearing 140°, about 800 m
    • Bearing 220°, about 800 m
    • Bearing 2°, about 16,000 m
    • Bearing 40°, about 800 m

11. Two waggle dances (model data)

    dance	waggle run (s)	angle clockwise from vertical (°)
    dance P	1.0	70
    dance Q	3.0	70

12. 7.

    Noah reads two dances from one hive at the same time. Distance grows in proportion to run length. Which statement does the card support?

    • Different kinds of resource, since the runs differ
    • Same distance; Q's place lies in a different direction
    • Same direction; Q's place is two times as far as P's
    • Same direction; Q's place is three times as far as P's

13. Waggle dance card (1 s of run = 400 m; a bee flies 8 m each second) (model data)

    dance	waggle run (s)
    dance 3	2.5

14. 8.

    Pia decodes the dance. About how long does the one-way flight to the resource take?

    • About 8,000 s: 1,000 m × 8 m each second
    • About 250 s: 2,000 m for the round trip ÷ 8
    • About 2.5 s, the same number as the run
    • About 125 s: 2.5 × 400 = 1,000 m, and 1,000 ÷ 8 = 125

15. Use the table

    Emperor penguin huddles in the Antarctic winter (data: Gilbert et al. 2006)

    measure	value
    average outside temperature	−17 °C
    temperature the birds felt in huddles	above 0 °C
    warmest temperature in a huddle	37.5 °C
    penguins fitted with data loggers	8

16. 9.

    Ren reads the table. By at least how much did huddling raise the temperature the birds felt?

    • 37.5 °C, the warmest huddle reading
    • More than 17 °C, from −17 °C to above 0 °C
    • Less than 17 °C, since the outside air was already cold
    • About 54.5 °C, from −17 °C to 37.5 °C
17. 10.

    Tala reads the table. A bigger spread means huddle lengths differ more. What does the spread say about the huddles?

    • Huddles lasted the whole winter, since males huddled for 38% of their time overall
    • Each huddle lasted 1.7 h more than the average
    • Huddle lengths varied widely, so a huddle did not stay together all winter
    • Every huddle lasted about 1.6 h, since that is the average