1. Around 400,000 years ago the temperature of earth began to increase, causing animals such as brown bears to head north towards the Artic. Genetic evidence shows that modern day polar bears evolved from these brown bears.
Explain how this would have happened and how polar bears are better adapted to the artic than their ancestors. [6]

2. Some polar bears were adapted
Levels
Expected responses
Level 3
All information in answer is relevant, clear, organised and presented in a structured and coherent format. Specialist terms are used appropriately. Few, if any, errors in grammar, punctuation and spelling (5-6 marks)
Level 2
For the most part the information is relevant and presented in a structured and coherent format. Specialist terms are used for the most part appropriately. There are occasional errors in grammar, punctuation and spelling (3-4 marks)
Level 1
Answer may be simplistic. There may be limited use of specialist terms. Errors of grammar, punctuation and spelling prevent communication of the science (1-2 marks)
Level 0
Insufficient or irrelevant science. Answer not worthy of credit.
(0 marks)
Some polar bears were adapted
They survived for longer and had more offspring
Polar bears are white so they are camouflaged
Large amounts of fat for insulation
Any other named examples of adaptations
Survived for longer and had more offspringe
Higher Level
There was variation in the population naturally
The traits of the better adapted bears were inherited by their offspring

13. The grand canyon formed about 6 million years ago
The grand canyon formed about 6 million years ago. Explain how the two different species of squirrel could have developed from a common ancestor [6]