Biodiversity and why it keeps ecosystems steady
Grade 9 Science Worksheet
Circle the best answer.
Read this first
Plants counted in one meadow (model data)
species plants clover 120 yarrow 40 plantain 20 dandelion 20 total plants 200 Kira reads the table. What share of the plants in the meadow belongs to the most common species?
- 75%: 120 out of 160, the two largest counts
- 20%: 40 out of 200 plants, the second species
- 25%: 4 species share the plants evenly
- 60%: 120 out of 200 plants
Three model communities (model data)
community species share of the commonest species (%) X 8 90 Y 8 15 Z 4 25 Milo reads the table. Which community is the most diverse?
- Community Z: its species are the most evenly shared, 25% each
- Community X: its commonest species has the biggest share, 90%
- Communities X and Y tie: each has 8 species
- Community Y: it has 8 species and none of them dominates
Growth in two plots (model data)
plot species before the dry year during the dry year D 16 480 360 L 1 320 160 Jun reads the table. By what percent did the growth of plot D change in the dry year?
- It fell 0%: a plot with many species does not change
- It fell 25%: 120 ÷ 480
- It fell 75%: 360 ÷ 480, the share left
- It fell 33%: 120 ÷ 360
Noah reads the table. By what percent did the growth of plot F change in the dry year?
- It fell 52%: 130 ÷ 250, the share left
- It fell 25%: 160 ÷ 640, the change of plot E
- It fell 48%: 120 ÷ 250
- It fell 92%: 120 ÷ 130
Zee reads the table. Which plot’s growth changed by the larger percent in the dry year?
- Plot G: it lost more growth, 200 grams against 150 grams
- Neither: the two plots changed by the same percent
- Plot H: it fell 50%, against 25% for plot G
- Plot G: it had more growth left, 600 against 150
Growth in one plot (model data)
time growth (grams per square meter) before the dry year 400 during the dry year 300 a year later 390 Resistance is how little a plot changes during an event. Pia reads the table. Which comparison shows the plot’s resistance?
- Growth before the dry year, by itself: 400
- A year later against the dry year: 390 against 300
- A year later against before: 390 against 400
- The dry year against before: 300 against 400
Growth in four plots (model data)
plot species normal dry year a year later P1 1 300 150 300 P2 2 500 260 500 P3 16 1000 750 1000 P4 32 800 624 800 Luz reads the table. Which statement fits the table?
- The four plots were equally resistant because all ended at their normal growth
- Plots with more species recovered faster, since they lost less in the dry year
- Plot P1 was the most resistant because it lost the fewest grams, 150
- Plot P4 was the most resistant, losing 22%, and all four plots were back to normal a year later
Gene versions in two wildflower populations (model data)
version of the gene population P plants population Q plants version 1 40 100 version 2 30 0 version 3 20 0 version 4 10 0 Esme reads the table for two populations of one wildflower species. Which has more genetic diversity?
- Neither: genes inside one species do not count as diversity
- The same: both populations are one species, so their species diversity is equal
- Population P: its plants carry 4 versions of the gene, against 1 in Q
- Population Q: it has the most plants with one version, 100
Dry-year growth by gene version (model data)
gene version growth per plant (grams) population P plants population Q plants version A 20 90 100 version D 50 10 0 Kira reads the model data. Which population grew more in total in the dry year?
- Population P: 2,300 grams, against 2,000 for Q
- Population P: 3,500 grams, counting 35 grams for each plant
- The same, 2,000 grams: each population has 100 plants
- Population Q: 2,000 grams, against 1,800 for P
Gene versions in one clover population (model data)
version of the gene plants version 1 60 version 2 40 Tala reads the table for a clover population. Which change would raise its genetic diversity?
- Adding plants that carry a new version of the gene
- Adding plants of a different species to the meadow
- Adding a pond beside the meadow
- Adding more plants of the two versions already there