Category: Exam Tips

How to choose statistical tests in A-level biology

Statistical tests are tools scientists use to spot important results – those rising above the randomness or “noise” in the universe. We use statistical tests in A-level biology, too. Even if a change in our data “looks” dramatic by eye, the test provides the unbiased reassurance to make our conclusions confidently.

Statistical tests work by setting a threshold (called the probability value level, p-value level or confidence level) used to spot significant changes from differences that could be explained by randomness in our measurements. Only data rising above this threshold gain the title “significant”. 

But how do we know which statistical test to use?

Choosing statistical tests in A-level biology

Firstly, some good news – you don’t need to memorize any mathematical formulae! If you need them in the exam, they will be given to you. But you do need to know how and when use the tests. (And if you are with the OCR or Edexcel exam boards you may have to actually do some calculations.)

Which statistical test we use depends on what best suits your data. We have a choice of three different statistical tests in A-level biology:

Chi-squared test – used when looking at differences between frequencies (data that is counted) in different categories (known as discrete data).

Student’s t-test – used to look at differences between means (averages) of data involving measurements (like lengths, or times).

Spearman’s rank correlation coefficient test– used to look at the correlation between two variables in measured data.

Here is a diagram to help you choose:

statistical tests in A-level biology

Hopefully this helps with you choose between statistical tests in A-level biology exam questions! This blog is part of a larger study guide to A-level biology statistics (see below). I’ve also written about how to answer A-level biology evaluate questions, and application questions, but what about “Describe” and “explain” questions.

Good luck!

How to use statistical tests in A-level biologyThere’s much more help with statistical tests, p-values, significance etc. (and model answers to exam questions) in our shiny eBook “How to use statistical tests in A-level biology”, available in our shop. A purchase from our shop gives you a month’s free subscription to “ask an expert” – very useful for some exam practice 🙂

 

If you’d like to work through some A-level biology statistics questions, from exam boards like AQA, please get in touch with me at Woolton Tutors, and we can set up some online A-level biology tutoring sessions. If you have a few quick questions, have a look at our Ask an expert service.

Best wishes,

John

Dr John Ankers

Specialist online A-level biology tutor and academic wellbeing coach

https://wooltontutors.co.uk

How to answer A-level biology describe and explain questions

The wording of A-level biology describe and explain questions is  important.  Often when people lose marks in exams, it’s not due to being completely wrong, but slightly wrong – the answer might make perfect sense, but miss the point of the question. Very frustrating!

I’ve written about how to answer A-level biology evaluate questions, and application questions, (and how to choose a statistical test), but what about “Describe” and “explain” questions? What’s the difference? What does each question want from you?

Answering A level biology Describe Questions

“Describe” questions want to know what is happening in front of you – perhaps in a graph, a scientific diagram or a picture. You need to describe what you can see!

Describe and explain questions in A-level biology
A typical A-level Biology graph. Describe – What can you see? Explain – Why does it look like this?

Imagine the examiner doesn’t know any biology and can’t see the paper – your job is to tell them what’s going on. What is the line in the graph doing? What is the plant in the picture above doing in response to sunlight?

The line may show a relationship between two variables – look for their names on the axes of a graph. Can you see a correlation between temperature and enzyme activity? Or, for the plant picture, the bend of a plant and the light levels around it?

Steer clear of using “it” in your descriptions – use scientific names instead. “The gradient of the line is…” or “the line representing enzyme activity flattens after…”

Keep an eye on the number of marks the question is worth – these will tell you how many details you need to mention.

Answering A level biology Explain Questions

Explain questions want to know why something is happening. You may still have a graph in front of you, but why does it look like that?

Focus on scientific explanation – what is going on “behind the scenes”? If the graph is of enzyme activity, we might talk about how the enzyme meets the substrate and the effect of temperature on how often this happens – explaining why the graph points upwards.

Use clear language here, too. Instead of “it” use the correct names for whatever you are writing about. Clear language doesn’t have to involve lots of scientific words. The idea is that your points logically follow each other. This happens, then this happens… so in the graph this happens.

Use the word “because” in your answer – it’s a good way to focus yourself on the explanation rather than the description.

Answering A level biology “describe and explain” Questions

Some exam questions ask you to both “describe and explain”. Here you can be methodical – look at the number of marks for the question and divide it in half. This is the number of points you need to mention, including a description and explanation for each.

Remember for each pair of marks – first describe “What does this look like?” then explain “Why does it look like that?”

Answering A level biology Suggest questions

Some questions may ask you to “suggest an explanation” for a graph or an event in the text. This is slightly different to an “explain” question as it gives you a little more freedom.

There may be multiple reasons why something behaves as it does, or why a line flattens on a graph. Your job here is to pick a theory than makes sense, then argue how and why it explains what’s going on. The mark scheme will likely have lots of flexibility to allow for whichever explanation you choose.

Good luck!

You can find an expanded version this guide, with added bits including model answers to real exam questions, in our shiny eBook “How to answer A-level Biology exam questions”, available in our shop. A purchase from our shop gives you a month’s free subscription to “ask an expert” – very useful for some exam practice 🙂

 

If you’d like to work through some A-level biology describe and explain questions, from exam boards like AQA, please get in touch with me at Woolton Tutors, and we can set up some online A-level biology tutoring sessions. If you have a few quick questions, have a look at our Ask a scientist service.

Best wishes,

John

Dr John Ankers

Specialist online A-level biology tutor and academic wellbeing coach

https://wooltontutors.co.uk

How to answer A-level biology application questions

A lot of our tutees ask how to answer A-level biology application questions. Application questions (AKA “applied knowledge” questions or assessment objective 2, AO2 questions) challenge you to apply your knowledge in an unfamiliar setting. Essentially, they are biological puzzles, and you have all the information you need to solve them – the real challenge is working out how and where to start.

Here are a few tips to guide you through:

  1. Ask yourself – what topic is this?

Look for key words and phrases that give you clues to which topic area (or areas) the question relates to. There may be a lot of information in the opening part of the question here that you’ve not seen before – that’s ok! It’s designed that way. If there’s a strangely named chemical described as an enzyme, everything you know about enzymes and proteins might be useful. Do we have an unfamiliar gene? Great – now everything you know about transcription, translation, epigenetics and even genetic engineering could be relevant.

It’s best to start with a clear idea of the context of the question.

Continue reading “How to answer A-level biology application questions”

How to answer A-level biology evaluate questions

One of the most popular requests from online A-level Biology students is “How do I answer A-level biology evaluate questions?” (AKA assessment objective 3 (AO3) questions)

Usually, these questions involve scientific data and a conclusion made by a student, journalist or politician. The idea is to discuss their conclusions and decide how much you agree.

Here are a few tips to try:

1. Don’t be afraid to agree AND disagree

Evaluate questions are usually looking for a balance of your opinions. You probably won’t agree completely, or disagree completely with a conclusion and that’s fine. The good news is there are marks for providing evidence for and against.

2. Look for “sweeping” statements

Usually “evaluate” questions are testing your ability to spot where the “story” in the science has been misinterpreted. Often the conclusion over-reaches – maybe it says a drug “cures lung disease” when the data only shows an effect on cells in dish, or in rabbits rather than humans. Look for places where the conclusion and the data are mismatched. Continue reading “How to answer A-level biology evaluate questions”

How to revise for A-level biology (and everything else)

Students often ask for advice on how to revise. Learning is different from understanding, but we need both to get the marks in exams. We can prepare for different questions, like describe and explain, evaluate or application A-level biology questions. But sometimes there is no avoiding it – there is also a lot to learn. So how best to do it?

Here are a few tips for how to revise effectively. (I’m using “How to revise for A-level biology” as an example here, but these tips can be applied to other subjects, too): Continue reading “How to revise for A-level biology (and everything else)”

Five practical ways to help your child with exam stress

Exams, class tests and mocks can be stressful. For better or worse, they’re often a test of resilience as much as knowledge. Parents can help in a number of ways to manage their child’s exam stress.

It might not be easy – your child may “push back”. Explain that you want to help; perhaps show them this post. Hopefully you’ll find something useful here that you can work on together.

  1. Remember that they are the expert on the subject, so you don’t need to be.

Often parents ask me how they can support their children in subjects like maths or biology if they themselves didn’t take them at school (or if they did, it was a long time ago). To provide support, you don’t need to be experts – your children already are. Instead, you can be their “spotter” – like a gym buddy! Ask them what they need to work on, what list of facts they need to know and surprise them with questions out of the blue. While you aren’t providing teaching, you are motivating and encouraging your child.

  1. Help with time-keeping and list-making.

Students approaching exams often have a lot on their mind, so practicalities like organisation and time-management get pushed aside. Here, parents can help massively with their child’s exam stress.

Gently help them to create a working routine – ask which topics they feel they need to prioritise and help them to make a list. Keep referring back to this list (even if you don’t know anything about the topics yourself – this doesn’t matter!). If they are frustrated with a topic ask them if the issue is knowledge (“making it stick”) or understanding (do they “get it”?). Breaking topics down in this way helps your child to prioritise and manage issues. Sharing these lists is also a great way to work alongside teachers and tutors – it gives us something to focus on in the next tutoring session. Continue reading “Five practical ways to help your child with exam stress”

How to prepare for mock exams in Liverpool Schools

While we’re helping students nationally and internationally, we’re also working with local Woolton and Liverpool-based GCSE and A-level students facing mock exams just before or just after the Christmas break.

Students attending schools like Calderstones School, The Liverpool Bluecoat School, St Edwards, Belvedere and Life Sciences UTC might be wondering what the mocks are, how to prepare, and what the point of them is? Well, ok – let’s answer those questions:

Mock exams – what are they?

Both GCSE and A-level courses have mock exams designed to mimic the experience of the formal exams at the end of your course. The difference is they are not assessed nationally, but by your school. The school can choose their own dates, and also to set the content for the test.

Mock exams – how do I prepare?

Your teachers will give you a list of topics that may come up in the mock exams. If you’re in the first year of your course, this list may be pretty short. During revision, make sure you understand the topics on the list, then: practise, practise, practise! Find past papers on the exam board’s website (here is AQA and Edexcel). If you’re in the first year, stick to “paper 1” and skip any questions on topics that aren’t on your revision list.

Mock exams – what’s the point?

Mock exams give you valuable experience of the exam setting – questions against the clock in a room with your classmates. Take advantage of the chance to test yourself. Yes, your teacher will record your marks and follow you progress but that’s only to help you. Don’t be put off by the idea of the exam – treat it with curiosity – how well do you actually know the subject?

Good luck to all of our students, from home here in Liverpool or abroad and around the world. Hope your mocks go well.

Of course if you’d like some help preparing we can help with GCSE maths and sciences and A-level biology tutoring.

John.
Dr John Ankers
Woolton Tutors

John grew up in Liverpool, went to Bishop Martin Primary School, The Liverpool Blue Coat School, The University of Liverpool for an undergraduate degree, and back again for a PhD. He set up Woolton Tutors in 2014. He is also a parent governor at Woolton Primary School.

How to move from GCSE to A-level – tips for students and parents

A-levels can be a big step up from GCSE. There are more details, more depth and often some satisfying answers to questions left over from earlier lessons. For this reason, A-level subjects can feel like they make more sense than GCSE courses, while being more challenging.

Students sometimes wonder how to prepare for this leap. Parents often ask how they can best support their child in moving from GCSE to A-level, especially in subjects they themselves didn’t study at school. Don’t worry!

The transition to A-level doesn’t need to be scary, and what happens at home can be a big help – you may even have fun doing it.

Keep the end in sight when moving from GCSE to A-level

The good news is that, like GCSE, each A-level exam course has a clear path – its specification. Often, students are aware each exam board (AQA, Edexcel, OCR etc.) provides a course specification but often they don’t make use of it. It’s there for you to download. Treat it like a reference guide – it might not be bedtime reading, but it shows you where you are and what’s coming up. It also has some tips for what the exam questions will look like.
(As an example, here is a link to the AQA A-level biology specification) Continue reading “How to move from GCSE to A-level – tips for students and parents”

How to answer A-level Biology essay questions

The Synoptic essay question on paper 3 of the AQA A-level biology course carries 25 marks, so doing well can make a big difference to your overall grade. The essay encourages you to think across different topics (some call this “synoptic” or “holistic” thinking). This is also valuable for other areas of the exams, particularly the application questions.

Here are a few tips for tackling your A-level biology essay: (As an example, let’s use the title “The importance of movement in cells and tissues”)

  1. Think broadly…

Essay titles are deliberately vague to give you the chance to show your knowledge in a variety of topics. To help you to choose what’s most relevant, look out for subjective words like “movement” and “cells”. Think of the possible alternatives. “Cells”, for example, hints that you could discuss plants, animals, single-celled organisms etc. in your essay. “Movement” could mean short distances (across a membrane) or much further (circulation or mass flow) or even the whole tissue moving (phototropism). Continue reading “How to answer A-level Biology essay questions”

FIVE last-minute exam tips

Here are a few last-minute exam tips to help GCSE, A-level and international students with your exams. Let me know if they work for you – or if you’d add any more 😊

  1. Read the question.

This is the easiest piece of advice to follow, and the easiest to forget. Sometimes we scan a question quickly, spot a few key words and make an assumption about how to answer without reading on. I can’t understate this – please read the question. Read it twice. There might be clues in there. This is particularly important for questions with data and diagrams – make sure you understand what the chart shows before starting on your answer. Continue reading “FIVE last-minute exam tips”