Read data on a helpful trait spreading through a population
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
Moths on one tree trunk (model data)
moth color moths dark 20 light 30 all moths 50 Ari counts the moths on one trunk. What percent of the moths are dark?
- 20%: the count of 20, written as a percent
- 60%: the light moths, 30 of the 50
- 67%: 20 dark moths divided by 30 light moths
- 40%: 20 of the 50 moths are dark
Bacteria on one lab plate (model data)
bacteria count resistant 30 not resistant 170 all bacteria 200 Bo reads the counts from one plate sample. What percent of the bacteria are resistant?
- 0.15%: 30 ÷ 200 = 0.15, left as a decimal
- 85%: the bacteria that are not resistant, 170 of 200
- 30%: the count of 30, written as a percent
- 15%: 30 of the 200 bacteria are resistant
Seedlings in one garden patch (model data)
seedling color seedlings purple 8 white 17 all seedlings 25 Esme counts seedlings in one garden patch. What percent of the seedlings are purple?
- 47%: 8 purple seedlings divided by 17 white
- 68%: the white seedlings, 17 of the 25
- 8%: the count of 8, written as a percent
- 32%: 8 of the 25 seedlings are purple
Jun reads the bars. What percent of the moths in generation 2 are dark?
- 35%: the height of the generation 2 bar
- 20%: the height of the generation 1 bar, not generation 2
- 15%: the rise from the generation 1 bar to the generation 2 bar
- 50%: the height of the generation 3 bar, not generation 2
Luz reads the light-moth bars. The two colors make up 100% of each generation. What percent of generation 3 is dark?
- 50%: 100% minus the generation 3 light bar of 50%
- 150%: 100% plus the light bar of 50%
- 65%: the light bar of generation 2, not generation 3
- 20%: 100% minus the generation 1 light bar of 80%
Dark moths per 100 moths (model data)
generation dark moths per 100 generation 1 20 generation 2 35 Milo reads the table. By how many percent points did the dark share rise from generation 1 to generation 2?
- 15 percent points: 35 − 20
- 35 percent points: the share in generation 2
- 75%: the 15 points are 75% of the 20 you started with
- 55 percent points: 20 + 35
Light moths per 100 moths (model data)
generation light moths per 100 generation 1 70 generation 2 45 Pia reads the table. By how many percent points did the light share fall from generation 1 to generation 2?
- 115 percent points: 70 + 45
- 36%: the 25 points are about 36% of the 70 you started with
- 25 percent points: 70 − 45
- 45 percent points: the share in generation 2
Dark moths in a woodland, per 100 moths (model data)
generation dark moths per 100 generation 1 20 generation 2 35 Ren reads the table. Which sentence about the change from generation 1 to generation 2 is correct?
- The 15 extra dark moths in 100 appeared because the woodland needed them
- The share of dark moths in the population rose; each moth kept its own color
- Each light moth turned dark during its life, until 15 more moths in 100 were dark
- The dark moths grew darker, so 15 more moths in 100 count as dark
Resistant bacteria on a plate, per 100 bacteria (model data)
round resistant per 100 round 1 5 round 2 30 Tala reads the table. Which sentence about the change from round 1 to round 2 is correct?
- The share of resistant bacteria rose because resistant bacteria left more offspring
- Each resistant bacterium got more resistant, which raised the share by 25 in 100
- The 25 extra resistant bacteria in 100 appeared because the plate needed them
- Each bacterium became a little more resistant, until 25 more in 100 were resistant
Zee reads the bars. What do the bars show?
- Each white plant turned purple, 20 more in 100 each generation
- The flowers of purple plants turned a deeper purple in each generation
- The share of purple plants rose across generations; a plant's own color stays the same
- Purple plants rose because the garden needed more of them over time