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
- 40%: 20 of the 50 moths are dark
- 67%: 20 dark moths divided by 30 light moths
- 60%: the light moths, 30 of the 50
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?
- 85%: the bacteria that are not resistant, 170 of 200
- 15%: 30 of the 200 bacteria are resistant
- 0.15%: 30 ÷ 200 = 0.15, left as a decimal
- 30%: the count of 30, written as a percent
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
- 50%: the height of the generation 3 bar, not generation 2
- 15%: the rise from the generation 1 bar to the generation 2 bar
- 20%: the height of the generation 1 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 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: it has more moths in total, so dark moths are a larger share
- Trunk B: its bar is taller, so dark moths are a larger share there
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
- 4 percent points: 40 ÷ 10
- 50 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?
- 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 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
- The 15 extra dark moths in 100 appeared because the woodland needed them
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 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
- 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
- Purple plants rose because the garden needed more of them over time
- The share of purple plants rose across generations; a plant's own color stays the same