BIOL 303Introductory Developmental Biology and Embryology
- Units
- 0.50
- Faculty
- Science
- Subject
- Biology
Not in the current Undergraduate Calendar. Shown as it appeared in 2025–26.
When it runs
- F24
- W25
- S25
- F25
- W26
- S26
- F26
- W27
- S27
Ran in 2 of the last 7 terms. Winter 2027: not on the schedule. Spring 2027: schedule not out yet.
Fundamental processes and concepts in embryonic development including the acquisition of multicellularity, organization of the early embryo, morphogenesis of tissues, major organ systems, fetal membranes, growth, differentiation, and analysis of common developmental defects.
Prerequisites
Antirequisites
None listed.
Leads to
Reviewed on UW Flow
53% liked it22% easy68% useful
From 89 ratings and 29 comments on UW Flow. The most helpful comments, quoted as written, without names. Read them all on UW Flow.
literally the hardest bio I've taken so far. most people say 308 is way harder but I think this course is a lot tougher. ridiculously difficult midterm and final (failed the midterm and barely passed the final). I studied super hard for the final and thought I did well but apparently not. DO NOT TAKE THIS COURSE UNLESS YOU HAVE TO. we haven't received our final grade yet but from my calculations, I think I barely scraped by this class with a low 50. I think it's also worth noting that I am a student who's always gotten 85+ in all my bios so I am super disappointed because I feel like I was set up for failure in this class. idk how many students failed this class but I imagine there were many
Dec 2021 · didn’t like it · 3 found this helpfulOn UW FlowRemove this
Honestly this course is not bad as everyone makes it to be. I took this along with BIOL 308 and BIOL 201 and did manage to get a 91%, there is alot of content but the midterms/exams do ask general questions. I barely went to classes and took notes from the powerpoints. Do the study questions and understand the general concepts/ideas from each topic. I would say this is a pretty useless course unless you are interested in research in developmental biology and mammals is the only topic that would be relevant for professional school exams. You will go through different animal system developments such as sea urchins, drosophila, birds, mammals, fish etc, try to understand the…
Dec 2023 · liked it · 2 found this helpfulOn UW FlowRemove this
This is one of the most horrible class I have ever had at the University of Waterloo. The midterm and final was absolutely brutal. The problem with this teacher is that she creates around 5-6 long answers worth 7-10 marks which ends up being worth more than 50% on the midterm/exam. I put in great effort into this class however she creates absurd questions that I have never seen before. We have not received our marks however I pray to god that it gets curved. I really hope that Stephanie McKay understands the stress and pressure she puts us under and hopefully learns from her teaching mistakes because no students should go through this stress. May I just say, PLEASE DONT take this course…
Dec 2021 · didn’t like it · 2 found this helpfulOn UW FlowRemove this
difficult final, hope it gets curved
put a lot of work into the course yet i didnt do too great, and the average was quite low.Dec 2021 · didn’t like it · 2 found this helpfulOn UW FlowRemove this
I doubt this course was ever this difficult. The final and midterm were insanely hard. Ive received mostly high 80's throughout my undergrad . This course has ruined my gpa, I put in lots of effort but her garbage short answer questions worth 7-10 marks were just too much. The Multiple choice was not easy but it was at least fair. The short answer questions would ask questions that were not clear, (i.e design an experiment for some scenario (10 mark question)). Yeah right, what does this even mean. a 10 mark short answer question should probably appear once on a final not 6 times. The professor is clearly very smart and passionate about her research and should not be teaching a class and…
Dec 2021 · didn’t like it · 2 found this helpfulOn UW FlowRemove this
Discussed on r/uwaterloo
99 posts and comments in 86 threads mention BIOL 303, November 2011 to December 2024. Quoted word for word, newest first; each reply sits under the post and the comment that started its branch. Search r/uwaterloo for newer posts.
Fall 2024
Biol303 final curved? 6 points, 0 comments
u/HelicopterFull5199: “Does bruce reed curve the final for biol303? Cause it was a total shit show and i cant fail this term. Genuinely scared.”
Fall 2023
Biol 303/308 midterm tips 1 point, 1 comment
u/Altruistic-Set1428: “Got both of these midterms one day apart and im a bit worried. Would love any tips/insight on how brutal they are. Just doing study questions/reading powerpoints/making notes but idk, theres so much content....”
One stop shop for course selection+tips to all biomedical/science students 6 points, 3 comments
u/-Leviathan-: “… I suggest taking VERY light courses to help with BIOL 303, which is the famous course that makes all Biomed students switch degree plans. …”
u/Altruistic-Set1428: “… i really dont have a good relationship with any of the professors that are supervisors, i am taking BIOL 303 right now with reed but unsure if he would let me, but i should prob ask him after im done this course. …”
Fall 2022
Want the honest truth on Social life at UW. 19 points, 8 comments
“I’m in 3rd year health sci and given I’ve only been in person 1 full all in person semester and found it super hard to find/make friends. …”
u/throwawaymed1235: “… I met them in 3rd year when one of them asked me to sit with them during BIOL 303. We supported each other a lot by sharing notes and extracurricular opportunities. Every one of us made it into med school eventually. I was the last one to make it in. …”
Spring 2022
Biol 303 exam 4 points, 0 comments
u/This_Kaleidoscope395: “For people who took biol 303 before, how far into final exam period was the exam?”
anyone in BIOL 303 CHEM 266 or PHYS 380?? 0 points, 1 comment
u/taffy02x: “or know of any groupchats pls”
Ebook rental 2 points, 1 comment
u/This_Kaleidoscope395: “Dumb question, but I bought the online textbook for biol 303. Now how do I access it?😂”
Winter 2022
BIOL 303? 1 point, 0 comments
u/This_Kaleidoscope395: “Does anyone know the grade breakdown of online biol 303?”
What is the hardest course you took in waterloo 29 points, 66 comments
u/throwawayTAOrgo: “Probably BIOL 301 (now BIOL 201) or BIOL 303. 303 was probably hardest because of midterms and exams, but 301 had so much memorization💀”
Fall 2021
How big are the biomed sci classes? 2 points, 6 comments
“Just wondering, how many people graduate the program every year?”
u/-Leviathan-: “… Some people also solely drop because of BIOL 303 (embryology, development) which, if not for online, would have slaughtered some people.”
Do grad schools care about course level and course load? 7 points, 6 comments
u/hockeyboythrowaway13: “… Only Biol 308 and Biol 303 are. Would this look bad on my transcript? Does course load matter as well, there is an emphasis placed on the last 2 years of my grades for most grad school programs I wish to attend. …”
BIOL 303,308 or 309? 0 points, 3 comments
u/uwstudent03: “Which one is easier to get a better mark in? Anyone have BIOL 3O3 or 309 course outline?”
u/YoSeanyBoii: “I took BIOL 303 and got 100% (pre-covid.. lol). If anyone needs a tutor for it, I can really help you out and ensure you get 90+.”
Check it elsewhere for Fall 2026
- Undergraduate Calendar, 2025–26The archived entry
- Requirements for Fall 2026Waterloo’s requisite checker
- Schedule of Classes, Fall 2026Instructors, rooms, live seats
- Quest Class SearchWhere you enrol
- Course outlinesSyllabi from past terms (UW login)
- UW FlowStudent ratings and reviews
- WClassesPast sections back to 2004, and who taught them
Calendar versions
Undergraduate Calendar
- 2020–21
- 2021–22
- 2024–25
- 2025–26 (shown here)
- 2019–20 and earlier on ucalendar