Harvard LS 1B: Genetics, Genomics, and Evolution
Life Sciences 1b is the spring half of Harvard's foundational life sciences year, covering genetics, genomics, and evolution: how variation arises, how it's inherited, and how populations change. With LS 1a it anchors the pathway into the life-science concentrations and pre-med requirements.
Fennie is independent and not affiliated with Harvard University. This is an unofficial study guide.
What makes it hard
Like its sibling course, LS 1b tests problem-solving over recall: pedigrees, crosses, linkage, and population-genetics calculations that demand setup skill, not memorized vocabulary. The genomics material adds data interpretation, meaning reading the output of an experiment you've never seen, which catches students who studied the slides instead of the problems.
What you'll cover
- • Mendelian genetics and pedigrees
- • Linkage and recombination
- • Molecular genetics and mutation
- • Genomics and sequencing data
- • Population genetics
- • Evolutionary mechanisms and selection
The LS 1B study guide
How to study for Harvard LS 1B, step by step.
- 1
Make problems the unit of study, not slides
LS 1b exams are crosses, pedigrees, and data interpretation, skills built only by working problems. Every study session should start with problems and use the slides as reference, not the reverse.
- 2
Drill the genetics setups until routine
Punnett squares, linkage maps, and probability-of-inheritance calculations have standard setups that must be automatic before exam reasoning can build on them. Volume now buys thinking room later.
- 3
Practice reading unfamiliar data figures
The genomics questions show you experimental output you've never seen and ask what it means. Practice with figures from lecture and the textbook: cover the caption, interpret, then check.
- 4
Connect every mechanism to evolution
The course's arc runs from molecules to populations. For each genetic mechanism, note what variation it creates and how selection sees it. The integrative questions on exams reward exactly that thread.
Today's LS 1B plan
What a Fennie Daily Plan looks like for LS 1B. Yours is built from your syllabus and adapts every day to your deadlines and progress.
- Review: Linkage and recombinationReview · 25 min
Work back through the LS 1B material on linkage and recombination. In the app, Fennie builds this from your own notes and syllabus.
- Practice: Molecular genetics and mutationPractice · 20 min
Targeted problems on molecular genetics and mutation, the kind LS 1B actually tests.
- Quick quiz: Genomics and sequencing dataQuiz · 10 min
Five generated questions to expose weak spots on genomics and sequencing data before the exam does.
- Preview: Population geneticsPreview · 10 min
A first pass over population genetics so the next session starts from familiar ground.
First plan free, no card required. Fennie is independent and unaffiliated with your school.
FAQ
Is LS 1b hard?
The concepts are approachable but exams demand genetics problem-solving and figure interpretation that memorization can't carry. Problem volume is the differentiator.
Do I need LS 1a before LS 1b?
LS 1a (or an equivalent foundation) is the designed predecessor, and the molecular vocabulary carries over. Check current placement guidance if your background differs.
Do pre-meds take LS 1b?
Yes. It's part of the standard foundational sequence feeding the life-science concentrations and pre-med coursework. Advising maps the exact pathway for your situation.