How living in groups helps animals survive
Grade 9 Science Worksheet
Circle the best answer.
Read this first
Group size and visits (model data)
group size visits a day 4 1 16 2 64 4 Luz reads the model table. Each visit takes one animal, picked at random. Which statement about one animal's daily chance of being lost is right?
- A group 16 times larger meets 4 times the visits, so each animal's chance falls 4 times
- A group 16 times larger meets 4 times the visits, so each animal's chance rises 4 times
- Each animal's chance falls 16 times, since the group is 16 times larger
- The group of 64 loses 4 animals a day against 1, so its animals are worse off
Ducks at day 10 (model data)
group ducks at start ducks lost by day 10 in flocks 30 3 alone 60 24 Milo reads the model data. Which statement compares how likely a duck was to be lost by day 10?
- Ducks alone were 4 times as likely to be lost: 40% (24 of 60) against 10% (3 of 30)
- Ducks in flocks were 4 times as likely to be lost: 10% against 40%
- Ducks alone were 8 times as likely to be lost: 24 ducks were lost alone against just 3 in flocks
- Ducks alone were 30 times as likely to be lost: 40% − 10%
Group size, risk and feeding (model data)
group size chance of being lost in a day (%) share of the day spent feeding (%) 2 8 70 8 3 62 32 2 40 Noah reads the model data on one species. Which group size gives the best balance of risk and feeding?
- Size 8: risk falls 5 points for 8 of feeding; size 32 gains 1 point of safety for 22 of feeding
- Size 2: it has the most feeding time, so it is the pick
- Size 8, because the risk and the feeding time are equal there
- Size 32: it has the lowest chance of being lost, so more safety makes the better balance of the two
Two dances for one patch (the sun moves 15° clockwise each hour) (model data)
dance time sun's compass bearing (°) angle clockwise from vertical (°) dance A 12:00 180 40 dance B 15:00 225 ? Pia uses the model rule: bearing to the patch = sun's bearing + angle. Dance B is for the same patch. What angle should dance B show?
- 5° clockwise from vertical, since 225 − 220 = 5
- 40°, the same as dance A, since the patch has not moved
- 45°, the amount the sun moved
- 5° counterclockwise from vertical, since 220 − 225 = −5
Two waggle dances (model data)
dance waggle run (s) angle clockwise from vertical (°) dance 1 2.0 40 dance 2 2.0 130 Ren reads two dances from one hive at the same time, using 1 s of run = 400 m. Which statement does the card support?
- The bees found different resources, since the angles differ
- Both patches are 800 m away, but in directions 90° apart
- Patch 2 is farther, since its angle is larger
- The two patches are the same place, since the runs match
Five dances for one patch (model data)
dance waggle run (s) 1 2.3 2 2.4 3 2.5 4 2.6 5 2.7 Zee reads five dances for one patch, using 1 s of run = 400 m. Which statement about the patch is best supported?
- About 920 m away, because dance 1 settles it
- Likely about 1,000 m away, within about 80 m either side
- Between 2.3 m and 2.7 m away
- Exactly 1,000 m away, since the middle run is 2.5 s
Use the table
A male's record (shares from Gilbert et al. 2006; the days are model data) (model data and Gilbert et al. 2006)
measure value days recorded 80 share of time huddling 38% share of huddling time above 20 °C 13% Tala applies the published shares to a model record. About how many hours was the temperature above 20 °C?
- About 10 hours, from 13% of 80
- About 30 hours, from 38% of 80
- About 95 hours: 80 × 24 × 0.38 ≈ 730 huddling hours, then 13% of that
- About 730 hours, the time spent huddling
Bo reads the study details. What can the study of 8 birds support?
- It shows nothing, since any study of 8 birds is useless
- It shows what happened to these 8 birds; it cannot fix a value for every colony
- It shows huddling raised the birds' body temperature to 37.5 °C
- It shows every emperor penguin colony huddles for 1.6 h at a time, since the 8 birds are enough to speak for them
Study card: minnows (model data)
part of the study entry fish in groups of 10 40 fish in a shaded tank fish alone 40 fish in a bright tank measured fish surviving at day 10 Esme reads the study card. Which flaw most weakens the claim that groups raise survival?
- Fish alone act as the control group, which makes the whole result invalid for a comparison
- Survival at day 10 cannot be used, so the study fails
- Forty fish is always too few, so the study means nothing
- Light differed between the tanks too, so group living is not the only change
Four study plans (model data)
plan how birds are placed trials per flock size plan 1 the healthiest birds go in the biggest flocks 1 plan 2 birds are assigned to flock sizes at random 6 plan 3 birds choose their own flock size 6 plan 4 birds are assigned at random 1 Jun reads four plans. Which plan best tests whether flock size changes survival when birds differ?
- Plan 3: birds choose, so the result matches real life closely
- Plan 2: random assignment evens out bird differences, and six trials show the spread
- Plan 1: the healthiest birds make the biggest flocks, so differences between sizes are clearest
- Plan 4: random assignment alone is enough, with a single trial each
