HESI A2 – Biology

The HESI A2 Biology section says that you need “a basic knowledge of biology” in order to succeed in the health professions.  I took my basic Biology class waaaay back in 9th grade.  Honestly, the only things I really remember from that class were dissecting a fetal pig and doing a genetic breeding experiment with fruit flies (there were fruit flies swarming in the school cafeteria for weeks after that experience).  Since then, however, I have also taken my nursing pre-requisites for biology: Microbiology, Pathophysiology, and two semesters worth of Anatomy & Physiology.  I had done fairly well in all those classes, so I hoped that was enough biology background to equal success on HESI A2.

Before I jump into the details of my HESI A2 Biology experience, I need to give a little disclaimer.  I never had to take HESI A2 when I applied to my nursing school, but I’ve gotten so many questions about it over the years that I signed up to take it earlier this year and I’m in the process of sharing my experience in a series of blog posts.

That being said…for those of you that are new to Your Nursing Tutor, I’m going to let you know up front that I think maintaining honesty and integrity are two of the most important things you need to do as a nurse.  And that includes not cheating on tests for any reason when you are a student nurse.   I will never share specific test questions, and I am not interested in buying or selling test banks for exams or textbooks.  If you email me to ask me for something like that, I’ll politely tell you no and refer you to this previous blog post.

Now that we’ve gotten that little disclaimer out of the way…

What is the HESI A2 Biology Section Like?

The HESI A2 Biology section has 25 questions.  There isn’t a time limit for each individual section on HESI A2, but your school will probably have a time limit for the entire test so it’s important not to spend too much time on any one section.  I took 18 minutes and 13 seconds to complete Biology, which means I averaged less than one minute per question (about 43-44 seconds per question, to be exact).  I found that to be a pretty reasonable pace because these are not critical thinking type questions, so you don’t have to spend as much time thinking about them.  Once you read the questions and answer choices, you pretty much either know it or you don’t.   

What types of questions are on the Biology section?

Unlike for Anatomy & Physiology, the Biology section of the official HESI A2 Review book offers a decent overview of the material you’re likely to be tested on.  Make sure that you’ve memorized the different parts of the cell (i.e. nucleus, ribosomes, golgi apparatus, etc) and their functions.  Cellular respiration, otherwise known as the process of “glycolysis” and the “Kreb’s cycle” should also be on your list of items to learn.  It’s definitely important to understand where ATP fits into the story, too.  

Genetics is also fair game on the HESI A2.  Make sure you remember how to do a Punnett square in order to predict the probability of a dominant or recessive trait being expressed in offspring (remember Mendel’s pea plants?).  By the way, reviewing this topic will pay off later when you take your Pediatrics class because it will help you to understand genetically linked disorders such as hemophilia and sickle cell.

Speaking of genetics, you’ll need a good understanding of DNA.  Luckily for me, my Microbiology class had covered DNA replication in-depth, so I still remembered a good bit of it for the HESI A2.  Make sure that you review the roles of all the different types of RNA’s during the DNA replication process while you’re at it.

Another topic that might be worth a quick review, but isn’t included in the official HESI A2 Review book, are the taxonomic categories (species, genus, family, etc).  I vaguely remembered them from my 9th grade biology class, but those memories were old, fuzzy, and unreliable.  I don’t think it would have taken too much of my time to get clearer on those details if I had known to review them, though.

So…What Was My Score?

I got 23 out of 25 of the Biology questions correct, which gave me a score of 92%.  To see how that compares to other HESI A2 test-takers, the minimum recommended score for the Biology section at this school was 80% (according to the official documentation, each school can set their own minimum recommended score).  My score report also stated that the National Average of all HESI A2-takers for Biology was a 75%, and the average of all HESI A2-takers at my school was a 74%.  So all things considered, I did pretty well.

The vast majority of the Biology knowledge that I needed for HESI A2 was covered in my Microbiology pre-requisite.  That’s fortunate, since it had been about a decade since I had completed basic biology!  And looking back at the questions I got wrong, I think that if I had actually studied the official HESI A2 Review book then I probably could have gotten an additional 2 questions correct.  (I didn’t really spend any time preparing for HESI A2 since I was only taking it to see what it was like, and not to try and get into nursing school).

Bottom Line

I though that the Biology section was straight forward with no real surprises.  The official HESI A2 Review book seemed to cover most of the material that I needed to know.  Alternatively, if you’ve recently taken an advanced Biology class like Microbiology, then you’ve probably studied most of what you need to know there.  Just like with A&P, having a good foundation in biology (especially genetics and the parts of the cell) will benefit you later on in nursing school.

 Which Biology topic would you most like to see me review here at Your Nursing Tutor?

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1 thought on “HESI A2 – Biology”

  1. Vanessa


    I am having a hard time passing my science section of the Hesi a2. I have studied tons of time and practically know the whole study book and questions on some websites online too, but for some reason I am still not able to pass this section. I am retaking the exam again next week and was wondering if you could maybe help me with the ones that I got wrong? I get really nervous when taking exams. I would greatly appreciate it if you would be able to help me.

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