A Level Biology - Natural and Artificial selection

**This Powerpoint specifically uses the Cambridge AS Level Biology Syllabus and covers all criteria for – Unit 1.1 The microscope in cell studies
**
Students will be able to -

1 explain that natural selection occurs because populations
have the capacity to produce many offspring that compete for
resources; in the ‘struggle for existence’, individuals that are
best adapted are most likely to survive to reproduce and pass
on their alleles to the next generation

2 explain how environmental factors can act as stabilising,
disruptive and directional forces of natural selection

3 explain how selection, the founder effect and genetic drift,
including the bottleneck effect, may affect allele frequencies in
populations

4 outline how bacteria become resistant to antibiotics as an
example of natural selection

5 use the Hardy–Weinberg principle to calculate allele and
genotype frequencies in populations and state the conditions
when this principle can be applied (the two equations for the
Hardy–Weinberg principle will be provided, as shown in the
Mathematical requirements)

6 describe the principles of selective breeding (artificial
selection)

7 outline the following examples of selective breeding:
• the introduction of disease resistance to varieties of wheat
and rice
• inbreeding and hybridisation to produce vigorous, uniform
varieties of maize
• improving the milk yield of dairy cattle

**Every Powerpoint includes learning objectives, a starter and plenary, suitable activities and review questions with mark scheme. We also provide a FREE pdf version of the file so it can easily be printed for students as a handout or uploaded to the school VLE system
**
Bring your Cambridge AS Level Biology lessons to life with our expertly designed teaching resources. Each unit is tailored to the latest syllabus, offering ready-to-use lesson plans, engaging experiments, and visually clear notes that save hours of prep time. Whether you’re new to the course or refining your approach, The Science Shelf gives you everything you need to boost student understanding and exam success — all in one place.