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?
- 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
- 20%: the count of 20, written as a percent
Jun reads the bars. What percent of the moths in generation 2 are dark?
- 15%: the rise from the generation 1 bar to the generation 2 bar
- 20%: the height of the generation 1 bar, not generation 2
- 35%: the height of the generation 2 bar
- 50%: the height of the generation 3 bar, not generation 2
Kira compares two trunks. The bars show counts of dark moths. Which trunk has the larger share of dark moths?
- Trunk B: it has more moths in total, so dark moths are a larger share
- Trunk A: 18 of 40 is 45%, and 24 of 80 is 30%
- Neither trunk: a chart of counts cannot show which share is larger
- Trunk B: its bar is taller, so dark moths are a larger share there
Luz reads the light-moth bars. The two colors make up 100% of each generation. What percent of generation 3 is dark?
- 150%: 100% plus the light bar of 50%
- 20%: 100% minus the generation 1 light bar of 80%
- 65%: the light bar of generation 2, not generation 3
- 50%: 100% minus the generation 3 light bar of 50%
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?
- 55 percent points: 20 + 35
- 35 percent points: the share in generation 2
- 15 percent points: 35 − 20
- 75%: the 15 points are 75% of the 20 you started with
Resistant bacteria per 100 bacteria (model data)
round resistant per 100 round 1 10 round 2 40 Noah reads the table. By how many percent points did the resistant share rise from round 1 to round 2?
- 300%: the 30 points are 300% of the 10 you started with
- 30 percent points: 40 − 10
- 50 percent points: 40 + 10
- 4 percent points: 40 ÷ 10
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?
- 45 percent points: the share in generation 2
- 36%: the 25 points are about 36% of the 70 you started with
- 25 percent points: 70 − 45
- 115 percent points: 70 + 45
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 dark moths grew darker, so 15 more moths in 100 count as dark
- The share of dark moths in the population rose; each moth kept its own color
- The 15 extra dark moths in 100 appeared because the woodland needed them
- Each light moth turned dark during its life, until 15 more moths in 100 were 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?
- Each bacterium became a little more resistant, until 25 more in 100 were resistant
- The 25 extra resistant bacteria in 100 appeared because the plate needed them
- Each resistant bacterium got more resistant, which raised the share by 25 in 100
- The share of resistant bacteria rose because resistant bacteria left more offspring
Zee reads the bars. What do the bars show?
- Each white plant turned purple, 20 more in 100 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
- The flowers of purple plants turned a deeper purple in each generation
