Year 6 Evolution and Inheritance Worksheet - Intermediate

Year 6 Evolution and Inheritance worksheet for Year 6 (Key Stage 2 / Year 3-6 (Ages 7-11)). Intermediate level science practice, aligned to the UK National Curriculum. Print-ready with answer key included.

Science•Key Stage 2 / Year 3-6 (Ages 7-11)•Animalsintermediate

28 views

Evolution and Inheritance: Clues from the Past

Year 6 Science • Ages 10–11 • Intermediate

Name:

Date:

Score:

Instructions: Explore how fossils provide evidence of life long ago, why offspring are similar to but not identical to their parents, and how adaptations can help populations change over many generations. Read each question carefully and use the evidence given to explain your ideas in the answer boxes.

Fossils: Evidence from the Past

Use the information in each question to explain what a fossil can tell us. Give a reason where asked. Fossils are usually formed when remains or traces are preserved in rock over a very long time.

1. A fossilised shell is found in rock high on a mountain. What does the shell suggest about the environment there long ago?

2. A fossil is the imprint of a leaf, but no leaf remains. Explain how an imprint could be preserved in rock.

3. Fossils of sea creatures are found in a layer of rock beneath fossils of land animals. What can this order suggest about how the environment changed?

4. Why can fossils provide evidence that some kinds of living things from the past are now extinct?

5. A fossil record has gaps because not every organism becomes a fossil. Give one reason why an organism might not be preserved as a fossil.

Offspring and Variation

Remember that offspring inherit features from their parents, but individuals of the same species are not exactly alike. Answer using the examples provided and distinguish inherited similarities from variation.

1. Two young rabbits have the same parents. Name one feature they may both inherit from their parents.

2. The rabbits have different-sized patches of fur. What does this show about variation within a species?

3. A puppy has its parent's coat colour but a different-shaped patch on its chest. Explain why offspring can resemble a parent without being identical to it.

4. In a group of young plants, some grow taller than others. Give one possible inherited difference that could contribute to this variation.

5. Why is it inaccurate to say that every offspring is an exact copy of its parent?

Adaptations and Survival

An adaptation is a feature that can help an organism survive in its environment. For each example, identify the helpful feature and explain how it could affect survival or reproduction.

1. A hare in a snowy habitat has white fur. Explain how this feature could help it survive.

2. Some insects have colouring that makes them difficult for birds to see among leaves. How could this adaptation affect the insects' chances of reproducing?

3. A bird has a long, narrow beak that can reach insects deep inside a tree. Explain why this beak shape may be useful.

4. In a dry habitat, a plant has a thick stem that stores water. Explain how this adaptation may help the plant survive.

5. A habitat becomes colder over many generations. Why might animals with thicker insulating fur be more likely to leave offspring?

Natural Selection over Generations

Read the population evidence, then explain how a helpful inherited variation can become more common over many generations. Natural selection acts on differences between individuals; it does not mean that an individual chooses to change its features.

A population of beetles lives on dark tree bark. Some beetles are dark and some are pale. Birds can spot pale beetles more easily. Dark colour is inherited by some offspring.

1. Which beetles are more likely to avoid being eaten by birds in this habitat?

2. Explain why the beetles that survive are more likely to have offspring.

3. If dark colour is inherited, what may happen to the proportion of dark beetles after many generations?

4. Explain how this example shows adaptation leading to a change in a population over time.

5. Do individual pale beetles turn dark because they need to survive? Explain your answer.

Read the Evidence

Use the data table and the scenario below. The beetles are the same species, and colour can be inherited. Compare the counts carefully, then use the evidence to explain a possible change in the population.

Beetles found on dark tree bark

Generation	Dark beetles	Pale beetles
1	20	30
5	42	18

1. How many dark beetles were found in Generation 1?

2. Which colour was more common in Generation 5?

3. By how many did the number of dark beetles increase from Generation 1 to Generation 5?

4. Give a reason, using the dark-bark setting, that could help explain the change in the numbers.

5. Do these results prove that every dark beetle survived and every pale beetle was eaten? Explain briefly.

Answer Key

Activity 1: 1. The area may have been underwater or near the sea long ago ; 2. The leaf was buried in soft sediment, which later hardened into rock and preserved its imprint ; 3. The area may have changed from a sea environment to a land environment ; 4. Fossils show that organisms lived in the past, and some kinds are not living today ; 5. It may have decayed or been eaten before it was buried, or it may not have been buried in suitable conditions

Activity 2: 1. Any inherited feature, such as fur colour or ear shape ; 2. Individuals of the same species can have different features ; 3. Offspring inherit features from their parents but inherit a different combination, so they can resemble a parent without being identical ; 4. Any plausible inherited difference, such as seed type or growth tendency ; 5. Offspring inherit a combination of features and can vary, so they are not exact copies

Activity 3: 1. White fur can camouflage the hare in snow, making it harder for predators to spot ; 2. Better-hidden insects may be less likely to be eaten and may have more chance to reproduce ; 3. It can reach insects in narrow or deep spaces in the tree ; 4. Stored water can help it survive when water is scarce ; 5. Thicker fur may keep them warmer, helping them survive and reproduce; they can pass inherited fur features to offspring

Activity 4: 1. Dark beetles ; 2. Beetles that survive may reproduce and pass inherited features to their offspring ; 3. The proportion of dark beetles may increase ; 4. Dark beetles are less visible, so more may survive and reproduce; over generations, inherited dark colour may become more common in the population ; 5. No. Individuals do not change colour simply because they need to; beetles with inherited dark colour may survive and reproduce more successfully

Activity 5: 1. 20 ; 2. Dark ; 3. 22 ; 4. Dark beetles may be harder for birds to see against dark bark, so more may survive and reproduce ; 5. No. The data give counts, not the fate of every individual; other factors may also affect the numbers.