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The history of human migration can be tracked by analysing mitochondrial DNA - Edexcel - GCSE Biology - Question 5 - 2016 - Paper 1
Question 5
The history of human migration can be tracked by analysing mitochondrial DNA. (a) Complete the sentence by putting a cross (X) in the box next to your answer. Mito... show full transcript
Worked Solution & Example Answer:The history of human migration can be tracked by analysing mitochondrial DNA - Edexcel - GCSE Biology - Question 5 - 2016 - Paper 1
Step 1
Complete the sentence by putting a cross (X) in the box next to your answer.
Answer
The correct answer is A: egg cytoplasm. Mitochondrial DNA is inherited exclusively from the mother, and this is due to the presence of mitochondria in the cytoplasm of the egg cell. Sperm contribute primarily DNA and very little cytoplasm.
Step 2
Explain the effect of the Ice Age on human migration.
Answer
The Ice Age had significant effects on human migration patterns. During this period, the following points are noteworthy:
- Increased Migration Forces: Harsh climate conditions led to the need for humans to find warmer regions, thereby forcing migration.
- Reduced Sea Levels: Glaciers locked up vast amounts of water, which resulted in lower sea levels. This allowed for the formation of land bridges that facilitated movement between previously isolated regions.
- Land Bridges: Such land bridges or shorter sea crossings made it easier for humans to migrate across continents, impacting population distribution and the spread of cultures.