Biological Drawings

The CIE AS and A Level Biology (9700) Advanced Practical Skills paper usually requires students to make observations of a photograph or specimen – which will often be on a microscope slide – and to record their observations as a diagram or drawing. A biological drawing looks simple and uncomplicated but it is imperative that students are provided with clear steps to success, lots of WAGOLLs, and plenty of opportunities to develop this important skill throughout the course.

A good biological drawing should:

  • have clear single lines (no ‘fuzzy’ or ‘feathery’ lines)
  • show an accurate overall shape and proportions
  • not include shading or colouring (even the nucleus!)
  • be large, using up most of the space provided but not going outside that space.

Students should use a sharp HB pencil and a good eraser. A ruler should only ever be used for drawing label lines.

Low-power plan diagrams

root 1

This type of diagram only shows the outlines of the different tissues. It should never show individual cells. Students may be familiar with the specimen (e.g. a cross section of a root or stem) but it is important that they only draw what they can see and not what they think they should see. Encourage students to look carefully in order to determine where one tissue ends and another one begins (look for differences in cell shape, size, densities and degree of staining).

For a low-power plan diagram of a microscope slide, CIE require that students are provided with a microscope with a x10 eyepiece lens and low-power objective lens (x10). An eyepiece graticule should also be fitted within the eyepiece and should be visible in focus at the same time as the specimen.

For a low-power plan diagram:

  • do not draw individual cells
  • draw all tissues completely enclosed by pencil lines (no gaps or crossed lines)
  • draw an accurate interpretation of the distribution of the tissues (the eyepiece graticule can be used without calibration to help draw the correct proportions).

High-power diagrams

high power 1

A high-power diagram generally does show individual cells. For a high-power diagram of a microscope slide, CIE require that students are provided with a microscope with a x10 eyepiece lens and high-power objective lens (x40).

For a high power diagram:

  • draw only a few representative cells
  • draw the cell wall of all plant cells (usually as a double line)
  • do not draw the nucleus as a solid blob (this is a particularly common error).

Labelling diagrams

label 1

A ruler should always be used to draw label lines. The label lines should stop exactly at the structure or tissue that is being labelled. A sharp pencil should be used for all label lines and labels.


Here is a workbook with checklists (self or peer) that I have produced to help AS and A Level Biology students with their biological drawing skills.




Allopatric Speciation in the Lower Congo River

Central Africa’s Lower Congo River is home to an extraordinary assortment of fish—many truly bizarre. This  video by Science Bulletins, the American Museum of Natural History’s current-science channel, features Museum scientists on a quest to understand why so many species have evolved there. It provides an excellent case study of allopatric speciation and helps to dispel the myth that populations only ever become isolated on islands. A Google Form worksheet to accompany the video is available here.

Desert Island Apps for Teachers


There are thousands of websites and apps aimed at teachers but if you had to pick just 10 that you couldn’t live without – the digital bare essentials of a 21st Century classroom, your desert island apps – what would they be?

Here, in no particular order, are mine.

1. Google Drive and Google Classroom

Google Drive includes Google Docs, Sheets, Slides and Forms as well as many other GAFE (Google Apps for Education). Google Classroom is a learning platform for schools which brings it all together in a secure online environment. Drive and Classroom allow students to collaborate and share files quickly and teachers to create and distribute assignments, flip learning, grade work, and post notices. Indispensable.

2. Kahoot!

Without doubt this would be the students’ choice. Kahoot! is an enjoyable, game-based learning platform with many similarities to (the also excellent but less jovial) Socrative. Use it to build fast paced multiple-choice quizzes and class surveys or pose questions at hingepoints during a lesson to receive instant feedback from all. Formative assessment at its most fun.

3. TES Teaching Resources

If you didn’t already know, TES Teaching Resources is a vast online library of mostly free lesson plans and classroom resources uploaded by teachers from around the world. To be honest, it’s not all great but there are some real gems in there which are more than worth the rummage. The site is also home to Teachers’ TV; a source of high quality videos on teaching and learning in Early Years, Primary, Secondary and FE, as well as films to help with continued professional development.

4. Adobe Voice

This one is relatively new on the scene but I love the simplicity of this application for making short, highly-professional-looking animated videos. I have written about it many times in this blog and confess to being a huge fan.


This site provides a variety of different stopwatches and clocks which can be used to add a sense of urgency to any starter activity or plenary, help keep younger students on task, or be clearly displayed during classroom-based tests.

6. Educreations

There are now a huge number of apps for creating video tutorials on the iPad but I have mostly remained faithful to Educreations as it works seamlessly with Google Drive and is so simple and intuitive to use. As well as making tutorials, I find it useful for providing feedback on larger pieces of student work (e.g. posters or models). I simply take a photograph, import it into Educreations, and then comment and annotate over it before sharing with the student via Classroom.

7. Twitter

We all know that Twitter is essentially a virtual staffroom for sharing resources, airing opinions and generating discussion but it can also be used to support learning in the classroom. For example, I have used it to provide a running news feed, tracked hash tags, connected with other classrooms and industry professionals, and encouraged students to send live Tweets during field trips. There are lots of possibilities. Not convinced? Here is a useful post by the brilliant @ICTEvangelist on the dos and don’ts of getting started in the pedagogical Twittersphere.

8. Armoured Penguin

The best site I have found for making crosswords and other simple word games. All free and easily converted into PDF.

9. YouTube

Create playlists of videos on particular topics, import videos into Google Forms as a flipped learning activity, post video tutorials, find sound effects to really bring your lessons to life, or simply mine this vast resource for educational audio visuals. TeacherTube, TedEd, How Stuff Works, BBC and Sick Science are just some of my favourite channels.

10. Visible Body 3D Human Anatomy Atlas

This is the only subject-specific entry on my list and a costly one (at the time of writing £18.99 from App Store) but it is a simply stunning piece of kit with an impeccable 3D interface offering students a far greater appreciation of anatomical structures than the flat drawings of a textbook ever could. The high-resolution graphics offer smooth zooming, panning and rotating capabilities and the concise labelling (showing the name of each structure and the system hierarchy to which it belongs) make it particularly useful for older students during organ dissections and demonstrations. Brilliant.

So there you have it, my top 10 teaching websites and apps. I would love to hear about your own desert island choices!


Lemonade Bottle Ecosystem

This is a wonderful activity in which students build a self-sustaining ecosystem containing primary producers (microscopic algae), primary consumers (brine shrimps) and decomposers (micro-organisms) inside a lemonade or coke bottle.

So long as you leave the bottle ecosystem on a sunny windowsill, the brine shrimps never require feeding and never run out of oxygen because the photosynthesising algae on which they feed, multiply by asexual reproduction. In turn, the algae never runs out of carbon dioxide, water or mineral salts because they are all recycled.

A book produced by Stephen Tomkins and Michael Dockery entitled ‘Brine Shrimp Ecology – a classroom-based introduction to ecology‘ is available to download copyright free from the British Ecological Society and contains a plurality of resources for ecological investigations including teaching notes, technicians’ guides and background information. The activities are primarily aimed at key stage 3 and key stage 4 students but could also provide the starting point for post 16 biology projects.

Blades Biological (based in the UK but accepting international orders) can supply brine shrimp eggs and algal cultures to get you started.


Alien Babies!

This is a fun and creative activity that helps explain how sexual reproduction generates genetic variation in offspring. Sadly, I can not claim this activity as my own – I found it on TES a few years ago and have tweaked it only slightly.


Before you start, check the students’ understanding of dominant and recessive alleles, phenotype and genotype. A simple way of demonstrating dominant and recessive alleles is to select two students to stand up and hold mini-white boards on which one has written ‘blue eyes’ (or a lower case b) and the other ‘brown eyes’ (or an upper case B). Ask the student with ‘brown eyes’ to stand in front of the student with ‘blue eyes.’ Highlight the fact that although both alleles / students are present, only the dominant allele is expressed in the phenotype / only one student can be seen.

You will need:

  • Chromosome cards (printed and cut out)
  • Large paper body cells (x2), egg cells (x2) and sperm cells (x2)
  • Genotype / phenotype table
  • Resources for building alien babies:
    • Brown and white marshmallows
    • Pipe cleaners
    • Coloured drawing pins
    • Cocktail sticks
    • Colouring pens
    • Nails
    • Wool or string


  1. Give one set of chromosome cards (male and female) to each pair of students (mummy and daddy aliens).
  2. Ask the students to arrange their chromosomes into homologous pairs inside the nucleus of a body cell.
  3. Turn over the chromosomes so that the letters can not be seen.
  4. Ask the students to randomly assort the chromosomes in each homologous pair into one of two sperm cells or one of two egg cells. Explain that this represents meiosis and that the gametes produced are haploid.
  5. Students should then select one egg cell and one sperm cell and push them together across the table. Highlight that this represents fertilisation and that the new diploid cell is the zygote.
  6. Ask the students to put the chromosomes in the zygote back into homologous pairs.
  7. Students should complete the genotype / phenotype table and use it as a guide to start building their alien babies using the resources provided. Use the cocktail sticks to join the marshmallows together.
  8. Once complete, ask the students to compare their babies. Are there any babies that are identical to one another or their parents? How much genetic material did each parent contribute? Why is it important that meiosis halves the number of chromosomes in each gamete? Ask the students to think about the steps involved in making their alien babies then consider how sexual reproduction generates genetic variation in offspring.

Teaching Meiosis and Mitosis

When teaching mitosis and meiosis at Key Stage 4 I find it effective to demonstrate using large cut-outs of cells and a small number of chromosomes made from pipe cleaners with beads representing the genes. The beads can be swapped from one chromosome to the other to show crossing over and the pipe cleaners twisted in the middle to represent two sister chromatids joined at the centromere.