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
   • 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
   • Higher in school Y: 40 minnows make a bigger target for each visit

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?

   • 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
   • Flock size changes how much food the birds find, not the scanning

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?

   • Less food for each nest, which the parasite column shows
   • More nests have parasites: 20% in a colony of 10 and 60% in a colony of 100
   • Fewer nests have parasites: 60% in a colony of 10 and 20% in a colony of 100
   • No cost: a bigger colony helps, since more adults can watch the nests
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 0 to 1: the school line falls from 20 to 19, a loss of 1 minnow
   • Days 5 to 6: the alone line ends at 9, its lowest point
   • Days 1 to 2: the alone line falls from 16 to 13, a loss of 3 minnows
8. 5.

   Kira reads the graph. Which statement is right about adding minnows to a group?

   • Survival keeps rising, but each added minnow helps less: 10 points from 5 to 10, 4 from 15 to 20
   • Survival will reach 100% in a big enough group, so a group has no cost
   • Survival rises by the same amount for each minnow added
   • Survival rises 20 points between 10 and 20 minnows, so doubling the group doubles how many survive
9. 6.

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

   • 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
   • 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

10. Waggle dance card (model data)

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

11. 7.

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

12. Two waggle dances (model data)

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

13. 8.

    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 three times as far as P's
    • Same direction; Q's place is two times as far as P's

14. 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

15. 9.

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

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

16. Use the table

    What huddling did for emperor penguins (data: Gilbert et al. 2006)

    measure	value
    average outside temperature	−17 °C
    huddling time above 20 °C	13%
    access to the warmth of huddles	equal for all birds

17. 10.

    Zee reads the table. Which claim about who got warm does the table support?

    • Huddles stayed above 20 °C for all of the huddling time
    • Only the birds in the middle got warm
    • Huddling helped the birds find food in winter
    • Every bird had equal access to warmth, though huddles were uneven