Read data on a helpful trait spreading through a population
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
Two woodlands in two generations (model data)
woodland dark, generation 1 all moths, generation 1 dark, generation 2 all moths, generation 2 North 20 50 42 100 South 30 200 50 200 Bo compares two woodlands. Which woodland's dark share rose by more percent points, and why?
- North: it started with the larger dark share, 40% against South's 15%
- Neither can be named, since the two woodlands count different totals of moths
- South: its share rose 10 percent points, and North's rose 2
- North: its count of dark moths rose by 22, more than South's 20
A flask before and after an antibiotic and a day of regrowth (model data)
bacteria before after resistant 20 380 all bacteria 10,000 500 Esme reads the flask counts. What percent are resistant after the antibiotic, and what do the 20 resistant bacteria before it show?
- 0.2%: 20 of 10,000, and resistant bacteria were already there before it
- 380%: the count of 380, written as a percent; resistant bacteria were already there
- 76%: 380 of 500, and resistant bacteria were already there before it
- 76%: 380 of 500, and the antibiotic made 360 more bacteria resistant
Ari sees the tall share go up and down across six generations. Which explanation fits the data best?
- Selection: the share dipped to 36%, so short plants survive better
- Selection: tall plants rose 8 points in generation 2, so tall plants survive better
- Chance: the share swings by a few plants and has no steady direction
- Chance: but the share should stay at exactly 40% in each generation
A small and a large population of plants, percent purple (model data)
generation population of 20 population of 2,000 generation 1 30 30 generation 2 35 36 generation 3 25 42 generation 4 30 48 Jun reads the table. Which statement about the two populations is best supported?
- Both populations show selection, since the purple share changed from one generation to the next
- The large population shows a steady rise that selection can explain, and the small one can be chance
- The small population shows selection, since its share rose 5 points in generation 2
- Each plant in the large population turned more purple with each generation that passed
Tall plants before and after a dry year (model data)
plants before after tall 1,000 900 all plants 10,000 1,500 The count of tall plants fell after a dry year. Kira asks if tall plants lost ground. What is the best reading?
- Yes: tall plants are 900 of 1,500, which is 6%, down from 10%
- Yes: 900 tall plants is fewer than 1,000 before, so tall plants lost ground
- No: the tall share rose from 10% to 60%, since short plants fell faster
- Yes: the table has an error, since a count and a share cannot move apart
Notebook
Notes on dark moths (classmate's notebook), 4 lines. Columns: line, entry. Line 1: In generation 1, 20 of 80 moths were dark, which is 25%. Line 2: In generation 2, 45 of 90 moths were dark, which is 50%. Line 3: The share rose 25 percent points, so it rose by 25%. Line 4: Dark moths survived better on soot-darkened trunks, so their share grew.
Luz reads a classmate's notebook about dark moths. Which line has the mistake?
- Line 1: 20 of 80 moths is 20%, not 25%
- Line 3: 25 percent points on a start of 25% is a 100% increase, not 25%
- Line 2: 45 of 90 moths is 45%, not 50%
- Line 4: dark moths could not have survived better on soot-darkened trunks
Notebook
Notes on a flask and an antibiotic (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Before the antibiotic, 5 in 10,000 bacteria were resistant. Line 2: After three rounds, 7,200 in 10,000 bacteria were resistant. Line 3: So the antibiotic changed the bacteria and made them resistant. Line 4: Resistant bacteria left more offspring in each round, so their share grew.
Milo reads a classmate's notebook about an antibiotic. Which line has the mistake?
- Line 2: a share of 7,200 in 10,000 is too large to be a real share
- Line 3: the resistant bacteria were already there, and the antibiotic did not make them
- Line 1: no bacteria can be resistant before an antibiotic has been used
- Line 4: resistant bacteria cannot leave more offspring than the others do
Moths in a sooty woodland: each survivor leaves 2 young like itself (model data)
moth color generation 1 survive to breed (percent) dark 30 70 light 70 30 Ren reads the table. Which claim goes with the right reason?
- Claim: the dark share rose to 70%. Reason: 70% of the dark moths survived to breed
- Claim: the dark share rose to 50%. Reason: dark moths survived at a higher percent and left more young
- Claim: the dark share rose to 21%. Reason: 21 dark moths survived to breed
- Claim: the dark share rose to 50%. Reason: 21 light moths turned dark during their lives
Tala reads the bars from round 1 to round 3. Which claim goes with the right reason?
- Claim: the share rose 400 percent points. Reason: 16 ÷ 4 = 4, and 400 is the change
- Claim: the share rose 16%. Reason: 20 − 4 = 16, and percent points are percents
- Claim: the share rose 80%. Reason: 16 ÷ 20 = 0.8, dividing by the later share
- Claim: the share rose 16 percent points, a 400% increase. Reason: 16 ÷ 4 = 4
Two flasks of bacteria, resistant per 10,000 bacteria (model data)
flask before after flask A, antibiotic added 12 9,400 flask B, no antibiotic 12 15 Zee reads the table. Which claim goes with the right reason?
- Claim: the antibiotic made bacteria resistant in flask A. Reason: flask A rose from 12 to 9,400
- Claim: both flasks changed by chance. Reason: both shares are different after the test
- Claim: flask B shows selection too. Reason: its share rose from 12 to 15 per 10,000
- Claim: selection raised resistance in flask A. Reason: flask B stayed near 12 per 10,000