Use the example of antibiotic resistant bacteria to explain directional selection.

DNA mutations happen randomly during division by mitosis. Some of these mutations code for antibiotic resistance. When a bacterial colony is exposed to antibiotics most bacteria without the resistance mutation will die - the antibiotics are a selection pressure. As a result, the bacteria with antibiotic resistence have a higher chance of surviving and dividing to create offspring. Over many generations, antibiotic resistance mutation will become more and more frequent - this is directional selection.

Answered by Vlad P. Biology tutor

10903 Views

See similar Biology A Level tutors
Illustration of a video tutorial

Need help with Biology?

One to one online tuition can be a great way to brush up on your Biology knowledge.

Have a Free Meeting with one of our hand picked tutors from the UK’s top universities

Find a tutor

Related Biology A Level answers

All answers ▸

Describe the process of DNA replication.


How can I understand enzyme-substrate function?


Explain how a mutation can cause cancer.


What is the role of adrenaline in glucoregulation?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2022

Terms & Conditions|Privacy Policy