Fossils and Evidence of Past Life — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
Fossils form in just a few day when animals die in Grade 3 science.
Corrected: Fossils form over millions of years when animals die in Grade 3 science.
Fossil formation takes millions of years, not days, because minerals slowly replace bone.
2. Fix the sentence:
When an animal dies, sediment cover it very quickly in Grade 3 lessons.
Corrected: When an animal dies, sediment covers it very quickly in Grade 3 lessons.
The singular noun 'sediment' needs the singular verb 'covers' for subject-verb agreement.
3. Fix the sentence:
Pressure and minerals turns buried bones into rock in Grade 3 science class.
Corrected: Pressure and minerals turn buried bones into rock in Grade 3 science class.
A compound subject joined by 'and' takes the plural verb 'turn' instead of 'turns'.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. In Grade 3 science, layers of mud and sand that bury a dead animal are called sediment.
Sediment is the layered mud, sand, and silt that buries remains and starts the fossil process.
2. In Grade 3 science, tiny bits of minerals seep into bones and slowly replace them with stone.
Minerals carried by water replace bone material to create a stony fossil copy.
3. In Grade 3 science, fossils usually take millions of years to form under the ground.
Fossilization is a slow process that usually takes millions of years to complete.
4. In Grade 3 science, heavy pressure from upper layers squeezes sediment into solid rock.
Pressure from upper sediment layers compacts lower layers into hard sedimentary rock.
Part C: True or False?
Read each statement. Circle True or False.
1. In Grade 3 science, a fossil can form in one afternoon if the animal is buried fast.
True False
Fossils form over millions of years, not in an afternoon, no matter how fast burial happens.
2. In Grade 3 science, being buried quickly by sediment helps an animal become a fossil.
True False
Quick burial protects remains from decay and predators, giving minerals time to work.
3. In Grade 3 science, minerals in groundwater can slowly replace bone with stone.
True False
Groundwater carries minerals that fill bone spaces and replace them, turning bone to rock.