Biology Interviews

The best place to start is Oxford's official information on preparing for interviews. But after you've looked there, read on to hear some students talk about their Biology interviews.

Lucy Williams

The interviews were much less stressful and more enjoyable than I expected. The tutors tried to make me as comfortable as possible - because they want to see you at your best. At my first interview I was asked to interpret some graphs, shown a picture of fossils that I could ask three questions on to learn as much as possible about them and asked a series of short questions. These included: why are ladybirds red and black, why do birds sing, and why do birds have warning calls?

At my second interview they asked a little on what I had put on my personal statement and asked to design some experiments to test certain hypotheses.

My advice to future applicants would be to stay calm, think before you answer a question and talk through your thoughts. Also be confident - you have an interview because the tutors think you have the potential to study at Oxford, so you should believe it too!

Lucy, Queen's, student from 2015
Bethaney Wilberforce

You're often shown an organism with weird features and asked to explain the adaptive significance. There's usually an open question about your favourite area of Biology.

Think out loud. Even if your answer is wrong, you can show that you have logical reasoning behind it. The Biology website contains more information and a video of a mock interview!

Bethaney, Worcester, student from 2013

I was given:

  • A skull
  • A video of lemmings jumping off cliffs
  • A video of genetically engineered bacteria moving around
  • Some graphs/data on blue tits and their nesting sites
  • A fossil (turned out to be bacteria, looked just like a rock to me)

For each I was asked to tell them about anything that seemed interesting, what I thought it was if they hadn't told me, and why I thought it had evolved that way. It was actually a lot of fun. I was also asked which of the books mentioned on my personal statement was my favourite, and why I liked it so much.

Meg, Balliol, student from 2014

"Why Biology?". I said I thought that it was an exciting time to be in Biology as humans are not only able study nature but adapt it to our own purposes. He responded by asking "What do you think has been the most pivotal discovery that has facilitated this change?". Next was "If you could create any piece of technology to aid biological discovery and you weren't constrained by any constraints or the laws of physics what would you make?" In response to me suggesting I would produce a capsule one could enter (like a deep sea submarine) which would scale up the atomic world to the visible world in 3D without any microscopes, he asked "Do you really think this would lead to new discoveries?" To this I explained how most of what we know about the atomic world comes not from seeing it directly but from seeing its effects on things we can see. For this I used the analogy of Brownian Motion. I then explained that discoveries therefore could be made much faster if we saw biological reactions happening with our very eyes rather than having to spend time devising tests to prove a reaction has or hadn't happened.

Change of topic: I am presented with several specimens and asked to identify each of them and explain how they get their 'food'. The specimens are an ash twig covered in yellow lichen, a plastic stag beetle, a pine cone and green moss. They wanted to know how the lichen gets its food - I explained how I wasn't sure if lichen was a protist or a fungi. The interviewer told me that scientists are not sure themselves if lichens are fungi or algae as it contains both. He explains that they exist in a symbiotic relationship and asks me to describe how this might work. I suggested A) Fungi are nitrogen fixing. Fungi convert nitrogen gas into nitrates which the plant uses to produce proteins. In return the fungi may be given sucrose from the plant. B) Like a common species of American lawn grass I read about…fungi may produce toxins which are actively transported by the plant from the roots to the stem tips to protect them from herbivory. In return fungi receive sucrose like before.

Change of topic. I am presented with a bar graph (on a logarithmic scale) showing the number of bases in the DNA of various organisms. Two species of bacteria reside at the bottom with a low number of bases; an amoeba sits at the top; and humans reside somewhere in the middle. I'm asked "What strikes you most about this graph?" In response to my observation that there is no correlation between size or apparent complexity of an organism and its number of bases "What might be the reason for this?". I say that the number of bases simply shows the number of different proteins that the organism can produce and doesn't say anything about the quality of the proteins or how they interact. They prompt for more reasons, so I suggested the idea that the Amoeba may simply contains lots of introns and not many exons. "Why do you think the bacteria don't have very many bases?" I stated idea that DNA not packaged in nucleus, so don’t coil round histones, so may not be as compact, so may take up more space, so may have greater cost to organism. Then said that I believe bacteria are physically smaller than amoeba/human cells before being interrupted.... "Are bacteria always smaller?". I said I had believed that bacteria were smaller as I had never seen one under a microscope whilst looking at other cells, but that I would not be surprised if I am wrong. He leaves the subject and leaves me to continue answering the question before. I back track and suggest that my idea for physical size may be unlikely to be the cause as DNA is very tiny in comparison to the physical size of the cell and thus size is unlikely to be a limiting factor. I suggest that bacteria have some DNA in plasmids and that plasmids may need to be small enough to pass through a conjugation between cells. He accepts these suggestions and tells me the real reason which is that bacteria do not have lots of DNA which is that bacteria do not have vesicles so cannot transport molecules round the cell. They rely on diffusion and so large molecules can’t diffuse so efficiently. I was not aware of this. At the end I was asked if I had any questions.

At the start of my next interview I am presented with a piece of paper with an image of two maize plants. One I am told is a wild type, the other is a cultured for food production. I am asked to explain the visual differences between the. (The modern variant has a much larger fruit. The modern fruit is yellow but the wild is green. The modern has fewer leaves but larger leaves. The leaves originate from the stem rather than originating from many shoots coming off the main stem in the wild type). "Why do you think that the modern variant does not have any shoots coming from the stem?" I respond with the idea that the thin shoots would not be sufficient the support the weight of the large fruit. "How do you think these changes in morphology occurred?" I explained how selective breeding worked to which he told me I was correct. He then turns the page and gives me more information. It tells me that both the wild plant and the domesticated plant shown to me are homozygous for ALL alleles. "How would you go about confirming that they were homozygous?" At this point I asked for paper and started drawing punnet squares. I suggested crossing it with a homozygous recessive individual and demonstrated by the diagram how this would work (probably the worst bit of my interview). He explained that this would work, but relies on me knowing that the plant I am using is homozygous recessive. I struggle so he prompts me by saying "how about crossing it with itself?". I then use a diagram to show how by crossing it with itself you could tell. At this point somehow I suggest that size is likely to be continuous variation and coded for by multiple alleles. He asks me to assume that it is just coded for by one and that big is dominant to small. "If I crossed the wild with the big what ratio of small to big would I expect?" I draw it out and conclude that ¾ are big to ¼ small phenotypes – which he says is correct. He then turns the page to show me a load of genetic diagrams. But I have already drawn out all the diagrams it shows - so this page doesn't help me any more. He then turns to page to show me what actually happened from the cross. The picture shows two fruit with both yellow and green specs in them. "What going on here?". I suggest that the allele for colour is co-dominant.

"I cross these two plants together – what will be the probability of getting a small green plant?" It takes me quite a long time to work this through. After this he then shows me a picture of what actually happened when the 2nd generation is crossed with itself to make a 3rd generation. The offspring are of all different shapes and sizes, not ¾ big and ¼ small as I just predicted. Apparently the actual probability for a small green offspring is 1 in 1024 and he asks why this is. I explain how size may be coded for by more than one allele. I then explain that 45 = 1024. I suggest that if all genes for small size are recessive then it may be coded for by 5 different genes.

At the end, the interviewers asked me about my Extended Project Qualification.

student from 2015 St Hilda's student

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