fbpx

🐞 Organisms

What a subtopic title indeed – organisms! I didn’t even make it up myself, it’s the spec. This topic is really about evolution. The basics of evolution, such as mutation, genetic drift, natural and sexual selection and allele frequency are covered in the Scottish Higher topics Evolution and Mutations, so this topic builds further on those concepts.

 

Previously we learned that evolution is the change in heritable traits through generations, brought about by random shifts such as genetic drift, as well as directed shifts such as selection.

 

In small populations, genetic drift is more powerful because the relatively small background fluctuations in allele frequency can actually result in some alleles being lost altogether rather than just slightly decreasing, as may be the case in a large population.

 

The variation present between organisms at the DNA sequence level is enabled through mutations of the code in genes, or the change in a…

πŸ† Read 500+ topics for all 6 UK exam boards πŸ†

πŸ“ Enter now to claim your FREE 3-day trial and find answers to all your revision topicsΒ πŸ“
βœ”οΈ Just Β£3.49/month after thatΒ βœ”οΈ Scholarships & teacher plans availableΒ βœ”οΈΒ Cancel anytime

You explain everything so simply!Β πŸ™‚Β -SecretDuck on The Student Room
Just a huge thank you for spending your time helping others. I love your site and I’m seriously very grateful. No word of a lie -Neuron13 on The Student Room
Thank you for making all the content btw!Β -Serena Kutty on YouTube
Good topic notes and cool videos. I’ll definitely recommend it to my students.Β -Seema Sehgal (AQA Examiner and Biology Teacher) on LinkedIn