Category Archives: IBDP Biology
Mesolens: see thousands of cells in detail at the same time
Living Water Flea, captured through the Mesolens, by Brad Amos at LMB
Currently on exhibition as part of the Royal Society’s 350th anniversary celebrations, the Mesolens is a giant microscope that can show large field-of-view images of living specimens in incredible detail – thousands of living cells in focus and in detail at the same time. Until now, scientists have had to rely on low-mag light microscopes to obeserve living specimens, or use sections of dead specimens on an electron microscope in order to get high-mag images.
Mesolens vs Hooke
Robert Hooke first drew a human flea in his 1665 book Micrographia. Along with van Leeuwenhoek, Hooke kick-started microbiology, and so it is a fitting tribute that some 345 years later, LMB give us their flea images. You can pan and zoom across a Mesolens image by clicking here
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Check out this short article from Wired.com explaining how the Mesolens works, and go to the Laboratory of Molecular Biology’s official site for the Mesolens. Can you distinguish between it and a normal light or electron microscope? What advantages will this give to researchers?
The Guardian has a gallery of images from Mesolens, and there is a short video showing image density from the LMB site, as well as a teachers guide to microscopy.
DrosophiLab – Genetics Simulator
- Drosophila buscki
DrosophiLab is a brilliant, free and downloadable piece of software that allows students and teachers to edit fruit flies and carry out crosses. The teacher can use the chromosome editor to set up parent flies of any genotype and there are 20 genes and traits represented, on four chromosomes. This allows for simple monohybrid crosses, sex-linkage, gene linkage and many other combinations – so the problems you set can be differentiated by level. There is also a password-protected teacher setting, to restrict students’ access to results tables and chromosome maps (so they have to work it out for themselves!).
Here are our class resources:
Protocol sheets: DrosophiLab HL, DrosophiLab SL (pdf)
Fly files in this folder: http://www.box.net/shared/dy326rb01d
Chi-Calc (Chi-squared calculator, .xlsx)
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How to catch and observe Drosophila:
Catch Your Own Drosophila, from Access Excellence (lots of resources there)
And this is how you tell the sexes apart:
When trying to observe the flies for real, think about the following questions:
– How are you ensuring ethical treatment of the animals?
– How long would it take to determine the phenotypes of the number of flies you have set for your investigations?
– What difficulties do you encounter when observing the flies?
– What are the limitations or sources of error that might affect the reliability of your results?
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Why are fruit flies so important in science?
Science loves fruit flies, and there was even a fruit fly Nobel awarded in 1995 for studies in embryonic development. This links neatly to the assessment statements regarding the differentiation of cells through expression of different genes.
- Fly!
Fruit fly cells are relatively easily observed, and Drosophila makes for an ideal model organism for Mendelian genetics as it has a short life cycle, reproduces quickly and is easily phenotyped.
There is a biography of fruit flies called Fly: An Experimental Life, by Martin Brookes, and you can find out more about the Drosophila genome at http://www.fruitfly.org/.
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Image sources:
Drosophila buscki from Journal of Endocrinology
Fruit fly graphic and DrosophiLab banner from DrosophiLab
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E4: Neurotransmitters and Synapses
Review Nerves content from the Core before completing this topic.
Class presentation:
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Essential Biology E4: Neurotransmitters and Synapses
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The New Science of Addiction: Genetics and The Brain
From Learn.Genetics
Fantastic resources available from Utah, including the mouse party, neuron and synapse animations and an interactive involving pedigree charts and the role of genetics in addiction.
Spend some time here to really read around the subject of drugs and addiction – you’ll be glad you did and it really helps answer the ‘discuss the causes of addiction’ question!
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Drugs and The Brain
Jellinek is a Dutch drugs education website that has some great, accessible resources for neurobiology of drugs and the brain. Animations are available in multiple languages – why can’t more organisations be as internationally-minded as this?
Be patient though -it needs a lot of bandwidth.
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Neurotransmitters and Drugs:
Good powerpoint from HHMI
Excellent overview of effects of drugs (Harvard)
Amphetamines, Cocaine, Nicotine as excitatory psychoactives (McGill ‘The Brain’)
Benzodiazepines, Cannabis, Alcohol as inhibitory psychoactives (McGill ‘The Brain’)
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TOK and Biology: The Nutt-Sack Affair
Leader of advisory panel on drug safety sacked for disagreeing with UK government:
http://www.badscience.net/2009/11/the-nutt-sack-affair-part-493/
Read around the topic, and then answer these questions:
Nutt's Scale of Drugs
- How does this story show the conflict between science and politics?
- What do you feel the respective roles of science and politics should be in the government of a country?
- Suggest reasons why some drugs which are clearly very harmful, such as tobacco and alcohol, are still legal in many countries.
- If you were to form a new country and write a whole new set of drug laws, which would you make illegal or legal and why? Upon which sources of evidence would you rely in order to make your decisions? How would you balance political pressures with scientific evidence?
Find out more about drug laws and the rationale behind them in your own country and the countries you visit or live in.
Remember – regardless of your own opinion on drug laws, if you are caught breaking the law wherever you are, penalties can be very severe.
Creation: Darwin Movie
Due for release this week, Paul Bettany stars as Charles Darwin in the biopic Creation. Based on Randal Keynes’ (Darwin’s great-great grandson) biography Annie’s Box, it promises to be a good movie and has received great reviews from the Toronto International Film Festival and the Guardian.
Here, the makers discuss the challenge of creating an exciting movie based on the life of a scientist, when the ins-and-outs of everyday science work can be pretty mundane. It looks as though they are focusing on the personal aspects of Darwin’s life and relationship with his wife as he works on the manuscript.
Bettany as Darwin
For more listening, the movie is discussed in this week’s Science Weekly Podcast, with discussion from Caspar Melville (with some questionable ideas*). Richard Dawkins also guests, to talk about his new book The Greatest Show on Earth.
Sadly, the movie has not yet only just been picked up for US distribution. I wonder if the title has something to do with that – perhaps Annie’s Box would have been easier to swallow? I also wonder if we’ll get to see it here in Indonesia.
* EDIT: It appears he was ‘conned’ by the AIDS-denialist ‘House of Numbers’ and explains here.
The 11th Hour re-up: Human Impacts on Ecosystems
In 2007, Leonardo DiCaprio released his environmental call-to-arms, The 11th Hour. And it’s very good. It really knocks home the old proverb that we are not inheriting the Earth from our ancestors, but borrowing it from our children.
Update 2009: the whole film is available on GoogleVideo (as all good documentaries should be):
The movie contains contributions from the likes of Stephen Hawking, Nobel-winner Wangari Maathai and David Suzuki. Particularly useful is Gloria Flora‘s sentiment that we all vote, every day – even those who are too young to cast a ballot – by making informed choices about what we consume, spend our money on and throw away.
Watch It!
The first half of the movie is a talking-heads and imagery look at our impacts on the Earth, with plenty of soundbites and starting-points for further discussion. The political middle section describes how economic growth and interests are driving destruction. The final act is a great collection of ideas and hope – a call to arms and a realisation that the environmental movement is growing quickly and strongly. But is it going to be in time to save our species and the thousands that we drive to extinction each year?
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Now here’s Leo’s video message (including the ‘vote’ quote from Gloria Flora):
For some further reading, go to the 11th hour Action website.
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IB Biology students:
Here is a quick question sheet for the movie, linking some of the topics to the Ecology and Conservation option.
Higher Level students: pay attention to the parts about the role of trees in the environment, in particular through water-uptake. Also, do you understand how mycofiltration (using fungal mycelia) could be used to clean polluted soils?
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For good measure, here’s Linkin Park’s accompanying music video, What I’ve Done :
Statistical Analysis 2009
Here is the updated presentation for 2009, with more information on Excel and a worked set of examples with hummingbirds, to tie in with the natural selection topics.
And Geoff Browne kindly gave permission to upload his t-test powerpoint to slideshare:
Resources:
Updated Essential Biology 01 – Statistical Analysis (word)
Click4Biology statistical analysis page, with great help for calculators and excel
Excellent Handbook of Biological Statistics from John MacDonald
Sumanas statistics animations
Field Studies Council stats page, including the t-test
Open Door Website stats page and help with graphs and tables
Gapminder awesome human population stats tool
And this enlightening talk from Han Rosling: No More Boring Data!
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Using your calculator:
– Using the TI GDC (from Click4Biology)
– Using the Casio pdf download (from keymath.com)
Evolution (Core)
Ecuador Hummingbirds
Start with this reading on Evolution and Darwin: https://www.box.net/shared/6dx95t6ma6 and then watch this video of evolutionary researchers in action in Ecuador.
In the clip below, is Ross using the correct language when he describes the theory and evidence for evolution?
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Here is the class presentation
And the Essential Biology notes can be found here: https://www.box.net/shared/550sxdbx82
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There are many sources of interactives and animations on Evolution on the internet. Here are a few:
PBS Evolution has lots of high-quality activities and videos
BiologyInMotion has a very clear population evolution interactive
The Exploring Evolution weblab has examples of homologous structures and fossil evidence
MMHE has a pesticide resistance tutorial
And there are some good peppered moth simulations here and here
As always, sumanas has a great resource – this time on antibiotic resistance
And John Kyrk has a truly awesome timeline of the evolution of life
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Darwin resources:
Attenborough on Darwin: The Tree Of Life
Dawkins Darwin Lectures from OU/BBC
And of course, all of Darwin’s works are available online from darwin-online.org
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And here’s Dawkins on the evolution of the eye:
Classification
Grade 11 are starting out the course with a short “Nature of Biology” unit, made up of Statistical Analysis (and some practice with data), Classification, Evolution and a little introduction to ToK in Biology. Grade 12 are also looking at Classification at the moment, as part of the Ecology, Evolution and Conservation unit.
Here is the class presentation:
Download as pdf here: 5.5 Classification
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Work through this Essential Biology 5.5 Classification as you go through the presentation.
There are some activities you can download here:
- Shark ID Guide at Queensland
Invertebrate phyla cards and dichotomous key
Paired groups key-making activity: Spiders vs Beetles
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And here are the Click4Biology notes
There is also a great Environmental Science course online here: The Habitable Planet
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Have fun!
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