How helpful traits become more common over many generations
Grade 7 Science Worksheet - Building Confidence

Circle the best answer.
Ari measures seeds from four plants in one wildflower patch. The sizes differ. Which step of natural selection does the chart show?
- Selection: the biggest seeds are picked
- Inheritance: seeds copy the parent plant
- Fitting: the plants changed to suit the patch
- Variation: the plants differ in seed size
Esme grows seedlings from big-seeded and from small-seeded parents. The seedlings make seeds like their parents' seeds. Which step is this?
Wildflower parents and seedlings (model data). Comparison chart, columns: Parent plants | Seed size of their seedlings (mm). Row 1: Big-seeded parents | 9. Row 2: Small-seeded parents | 6. Wildflower parents and seedlings (model data). Comparison chart, columns: Parent plants | Seed size of their seedlings (mm). Row 1: Big-seeded parents | 9. Row 2: Small-seeded parents | 6. Row Parent plants Seed size of their seedlings (mm) 1 Big-seeded parents 9 2 Small-seeded parents 6 - Sameness: the seedlings share one seed size
- Selection: the largest seeds are picked
- Inheritance: seeds pass on parent traits
- Need: the seedlings grew big seeds to suit the patch
Medium ground finches, Daphne Major (real data: Boag and Grant 1981, via Open University OpenLearn). Comparison chart, columns: Generation | Average beak depth (mm). Row 1: Finches before the 1977 drought | 9.2. Row 2: Their offspring, born after the drought | 9.7. Bar graph: x axis Generation; y axis Average beak depth (mm), ticks every 2 from 0 to 10. Bars: Before drought 9.2; Offspring 9.7. Medium ground finches, Daphne Major (real data: Boag and Grant 1981, via Open University OpenLearn). Comparison chart, columns: Generation | Average beak depth (mm). Row 1: Finches before the 1977 drought | 9.2. Row 2: Their offspring, born after the drought | 9.7. Bar graph: x axis Generation; y axis Average beak depth (mm), ticks every 2 from 0 to 10. Bars: Before drought 9.2; Offspring 9.7. Medium ground finches, Daphne Major Generation Average beak depth (mm) Row 1: Finches before the 1977 drought 9.2 Row 2: Their offspring, born after the drought 9.7 real data: Boag and Grant 1981, via Open University OpenLearn 0 2 4 6 8 10 9.2 Before drought 9.7 Offspring Generation Average beak depth (mm) Jun reads the finch chart. What was the average beak depth of the medium ground finches before the 1977 drought?
- 9.2 mm
- 10.2 mm
- 9.7 mm
- 9.0 mm
Kira reads the finch chart. What was the average beak depth of the offspring born after the drought?
Use the picture in question 3.
- 9.2 mm
- 7.9 mm
- 9.7 mm
- 10.7 mm
Milo reads a science word list. Which meaning goes with the word variation?
- Differences in a trait among living things of one kind
- A trait that helps a living thing where it lives
- A change that is complete after one generation
- A change a body makes to fit its place
Noah reads a science word list. Which meaning goes with the word adaptation?
- A trait shared by the whole group, with no differences
- A difference seen between two kinds of living things
- An inherited trait that helps a living thing survive and have young
- A change a body makes when it needs something
Pia reads a science word list. Which meaning goes with the words natural selection?
- Each living thing changes its body to fit its place
- A trait that shows up in the whole group at once
- People choose which plants or animals have young
- Helpful inherited traits become more common over generations
Ren fills in the finch chart for the 1977 drought. Which answer goes in the cell with the question mark?
Daphne Major finches (real data: Boag and Grant, via OpenLearn). Comparison chart, columns: Time | Seeds left on the island | Finches that could crack them. Row 1: Before the 1977 drought | many seeds, small and large | finches with shallow and deep beaks. Row 2: During the drought | mostly large, hard seeds | ?. Daphne Major finches (real data: Boag and Grant, via OpenLearn). Comparison chart, columns: Time | Seeds left on the island | Finches that could crack them. Row 1: Before the 1977 drought | many seeds, small and large | finches with shallow and deep beaks. Row 2: During the drought | mostly large, hard seeds | ?. Daphne Major finches (real data: Boag and Grant, via OpenLearn). Comparison chart Time Seeds left on the island Finches that could crack them 1. Before the 1977 drought many seeds, small and large finches with shallow and deep beaks 2. During the drought mostly large, hard seeds ? - Finches with deeper beaks
- Finches that grew deeper beaks
- Finches that needed deeper beaks
- Finches with shallower beaks
Tala fills in the peppered moth chart. Which answer goes in the cell with the question mark?
Peppered moths and tree bark (real data: Christ's College Cambridge Darwin200 page; OpenStax Biology 2e). Comparison chart, columns: Time | Bark of the trees | Most moths were. Row 1: Before the Industrial Revolution | pale, with light lichens | ?. Row 2: 1895, Manchester | darkened by soot | dark. Peppered moths and tree bark (real data: Christ's College Cambridge Darwin200 page; OpenStax Biology 2e). Comparison chart, columns: Time | Bark of the trees | Most moths were. Row 1: Before the Industrial Revolution | pale, with light lichens | ?. Row 2: 1895, Manchester | darkened by soot | dark. Peppered moths and tree bark (real data: Christ's College Cambridge Darwin200 page; OpenStax Biology 2e). Comparison chart Time Bark of the trees Most moths were 1. Before the Industrial Revolution pale, with light lichens ? 2. 1895, Manchester darkened by soot dark - half dark, half light
- changing color to match
- light-colored
- dark-colored
Zee fills in the chart about tree bark. Which answer goes in the cell with the question mark?
Tree bark and clean air (real data: Christ's College Cambridge Darwin200 page). Comparison chart, columns: Time | Air | Bark of the trees. Row 1: Years of heavy soot | full of soot | darkened. Row 2: After clean-air laws | much cleaner | ?. Tree bark and clean air (real data: Christ's College Cambridge Darwin200 page). Comparison chart, columns: Time | Air | Bark of the trees. Row 1: Years of heavy soot | full of soot | darkened. Row 2: After clean-air laws | much cleaner | ?. Tree bark and clean air Time Air Bark of the trees Years of heavy soot full of soot darkened After clean-air laws much cleaner ? real data: Christ's College Cambridge Darwin200 page. Row 1; Row 2. - still darkened by soot
- lighter again
- darker and darker
- unchanged from before the laws