How to tell the difference between mitosis and meiosis

academics biology meiosis mitosis

If you’ve ever taken a biology class, you’ve most likely come across the concept of the cell cycle. Put simply, the cell cycle is the growth of cells, the replication of DNA, and the subsequent division of DNA, organelles, and cytoplasm that creates new cells. For eukaryotes, cell division is an essential part of both growth and reproduction. However, autosomal cells (cells of the body) and gametocytes (germ cells, or reproductive cells) divide in two different ways. We call these processes mitosis and meiosis, respectively.

It’s not always easy to remember what distinguishes each process, so we’ll break down the key differences here. But before we get into the details, let’s understand some basics:

Autosomal cells are diploid (2n). This means that they have 2 versions of each chromosome–one that came from mom, and one from dad. The human genome has 23 chromosomes, so each autosomal cell carries 46 chromosomes in total.

Gametes (sperm and egg cells) are haploid (n). This means that they have only 1 version of each chromosome. Each gamete carries 23 chromosomes in total. When 2 gametes combine during fertilization, the resulting zygote is diploid (2n), and has 46 chromosomes.

Now let’s talk about mitosis: the process of making more diploid (2n) body cells.

In the G1 phase of the cell cycle, the cell grows in size and creates more organelles.

In the S phase, the cell replicates all of its DNA. This does NOT mean that there are now 92 chromosomes, it just means that all 46 chromosomes have 2x the amount of normal DNA.

In the G2 phase, the cell once again grows. It also checks to make sure that a) it’s big enough to divide, and b) no mistakes have been made in DNA replication.

In the M phase, or mitosis and cytokinesis, the cell finally divides. It begins with prophase.

 

In anaphase I, the homologous pairs separate. Unlike in anaphase of mitosis, the centromeres of each individual chromosome do not split and separate sister chromatids; instead the entire chromosome moves toward one end of the cell, away from its partner.

In telophase I, much like telophase of mitosis, nuclear membranes reform around each new nucleus. The key difference is that once cytokinesis pinches off the two new cells, both are now HAPLOID (n). They contain only 23 chromosomes, but each consists of two chromatids. These chromatids would be identical, except the crossing over in prophase I has given them random portions of DNA from the homologous chromosome now in the OTHER cell.

Isaac graduated in 2020 with a BS in Neurobiology and Behavior from Cornell. As a student, he spent much of his time investigating diabetes treatments and bariatric surgery. He is an MD Candidate (2026) at Columbia University Vagelos College of Physicians and Surgeons .

Comments

topicTopics
academics study skills MCAT medical school admissions SAT expository writing college admissions English MD/PhD admissions strategy writing LSAT GMAT GRE physics chemistry math biology graduate admissions ACT academic advice interview prep law school admissions test anxiety language learning premed MBA admissions career advice personal statements homework help AP exams creative writing MD study schedules test prep Common Application computer science summer activities history philosophy mathematics organic chemistry secondary applications economics supplements research 1L PSAT admissions coaching grammar law psychology statistics & probability legal studies ESL CARS SSAT covid-19 dental admissions logic games reading comprehension engineering USMLE calculus PhD admissions Spanish mentorship parents Latin biochemistry case coaching verbal reasoning DAT English literature STEM excel medical school political science AMCAS French Linguistics MBA coursework Tutoring Approaches academic integrity chinese letters of recommendation Anki DO Social Advocacy admissions advice algebra astrophysics business classics diversity statement genetics geometry kinematics linear algebra mechanical engineering mental health presentations quantitative reasoning skills study abroad technical interviews time management work and activities 2L DMD IB exams ISEE MD/PhD programs Sentence Correction adjusting to college algorithms amino acids analysis essay art history artificial intelligence athletics business skills careers cold emails data science dental school finance first generation student functions gap year information sessions international students internships logic networking poetry resume revising science social sciences software engineering tech industry trigonometry writer's block 3L AAMC Academic Interest EMT FlexMed Fourier Series Greek Health Professional Shortage Area Italian Lagrange multipliers London MD vs PhD MMI Montessori National Health Service Corps Pythagorean Theorem Python Shakespeare Step 2 TMDSAS Taylor Series Truss Analysis Zoom acids and bases active learning architecture argumentative writing art art and design schools art portfolios bibliographies biomedicine brain teaser campus visits cantonese capacitors capital markets cell biology central limit theorem centrifugal force chemical engineering chess chromatography class participation climate change clinical experience community service constitutional law consulting cover letters curriculum dementia demonstrated interest dimensional analysis distance learning econometrics electric engineering electricity and magnetism escape velocity evolution executive function freewriting genomics graphing harmonics health policy history of medicine history of science hybrid vehicles hydrophobic effect ideal gas law immunology induction infinite institutional actions integrated reasoning intermolecular forces intern investing investment banking lab reports linear maps mandarin chinese matrices mba medical physics meiosis microeconomics mitosis mnemonics music music theory nervous system neurology neuroscience object-oriented programming office hours operating systems organization