Biology Question About Osmosis Stumped British Students
Last week, MustShareNews reported that harder A-Levels had stumped British students.
Results Decline After UK Makes A-Levels Harder To Meet Asian Standards
It turns out that harder GCSE exams at the end-of-secondary school have shaken students just as much.
The GCSE exams are the British equivalent of the O-Level papers, which Secondary 4 and 5 students sit for here.
In May, students emerged from their GCSE Biology paper, stumped by one question in particular.
“Why don’t carrots increase in mass when they’re boiled?”
Of carrots and potatoes
In case you’re confused, here’s a clue: it’s related to osmosis.
Osmosis refers to the process of water passing through a semi-permeable membrane from a less concentrated solution to a more concentrated solution.
This equalises the concentrations of solute.
The theory is popularly tested in Singapore exams as well, but here, we use potatoes instead of carrots as an example.
That used to be the case in Britain as well, according to this netizen:
But simply changing the vegetable in question and having it cooked threw plenty of students off.
https://twitter.com/faye_ush/status/996392785149333506?ref_src=twsrc%5Etfw&ref_url=https%3A%2F%2Fwww.huffingtonpost.co.uk%2Fentry%2Faqa-biology-gcse-exam_uk_5afbde03e4b06a3fb50bd98d
Roses are red
Biology is lame
Why do boiled carrots
mass stay the same? #aqabiology— ailsa (@comeonperry) May 15, 2018
The question also sparked a national conversation about the state of Britain’s education system.
Some teachers praised it for forcing students to think outside the box. Mr Gareth Sturdy, a science teacher, wrote,
It’s the kind of question that demands not just knowledge, but intellect – a flexibility of mind that can put knowledge to use to create insight and understanding.
And we can’t help but agree.
But what’s the answer?
So if you’ve skipped to the end of this article to see if your answer was correct, here it is.
A biology teacher from Singapore explains,
In room temperature water, carrots would increase in mass since water would enter its cells through the cell membranes by osmosis (given the difference in their concentrations). But boiling destroys the cell membrane of carrot cells, causing it to lose its partial permeability. This means that the carrot’s cell membrane becomes fully permeable, preventing osmosis from taking place. Their mass thus does not increase.
Did you get it right? Let us know what your answer is in the comments below.
Featured image from Emoji Terra.Â
