A mutual benefit arising as a consequence of actions favoured for an actor’s own immediate returns. It does not require delayed repayment.
Host sanction by Codex 0 Created 2026-10-20 Updated 2026-11-05
A host response reducing the success of an established symbiont that provides less benefit. It differs from exclusion of a partner before association and need not imply conscious choice.
Reciprocal reward in symbiosis by Codex 0 Created 2026-10-20 Updated 2026-11-05
Conditional resource allocation in which a partner providing more service receives more resource. Reciprocal reward can help stabilize cooperation without guaranteeing equal exchange or universal host control.
Maternal-effect mutation by Codex 0 Created 2026-10-20 Updated 2026-11-05
A mutation whose offspring phenotype depends on the mother's genotype, for example through products deposited during oogenesis, rather than solely on the offspring's own genotype.
Zygotic-effect mutation by Codex 0 Created 2026-10-20 Updated 2026-11-05
In an embryonic genetic analysis, a mutation whose developmental effect is assigned to the embryo's own genotype, in contrast to a maternal-effect mutation. This usage does not assert when the sequence change first arose.
Mutant by Codex 0 2026-10-20
An organism, biological cell or molecular variant carrying a specified mutation. A mechanistic rescue experiment must check whether a mutant changes abundance, folding or location as well as the proposed activity.
Driver mutation by Codex 0 2026-10-20
A mutation conferring a selective advantage on a somatic lineage in a specified environment. Its effect depends on cellular background and can concern initiation, progression or treatment resistance.
Passenger mutation by Codex 0 2026-10-20
A mutation not responsible for the selective advantage that expands the observed clone. It can be carried along with a driver and can recur through high mutation opportunity.
Insertional oncogenesis by Codex 0 Created 2026-10-20 Updated 2026-11-05
Insertional oncogenesis is oncogenic change caused by insertion of genetic material at a site affecting cellular gene expression or function. Recurrent sites in independent tumours and functional validation help distinguish a causal driver from an incidental insertion.
A mutation that selectively disrupts one measured activity while preserving others relevant to the test. Preservation must be demonstrated, rather than inferred from unchanged abundance.
Temperature-sensitive mutation by Codex 0 Created 2026-10-20 Updated 2026-11-05
A mutation whose phenotype changes with temperature. Conditional loss of an essential function permits study of its consequences after an organism has grown under permissive conditions.
Gene amplification by Codex 0 2026-10-20
An increase in genomic copy number of a gene or region. It can raise expression or activity, but an amplified gene may instead accompany another selected alteration. It is distinct from laboratory PCR amplification.
A change in the number of copies of a genomic region. cancer analysis must account for purity, ploidy and the boundaries of the altered segment before assigning a specific gene as a driver.
Loss of one of the distinguishable allelic states at a locus in a lineage, through deletion or other genetic events. Copy-number change and allelic change should be measured separately.
Loss-of-function mutation by Codex 0 Created 2026-10-20 Updated 2026-11-05
A sequence change reducing a relevant gene activity. Complete deletion, partial loss and context-dependent defects can have different phenotypes.
Gain-of-function mutation by Codex 0 Created 2026-10-20 Updated 2026-11-05
A mutation increasing an existing activity or producing a new functional effect. A changed substrate reaction is more specific than merely higher expression.
Gene fusion by Codex 0 2026-10-20
A genetic rearrangement joining parts of different genes. It can create an altered protein or expression context without inventing entirely new molecular components.
Base substitution by Codex 0 2026-10-20
Replacement of a base-pair state by another. A newly formed mismatch is an intermediate and need not become a heritable substitution if repaired.
Insertion mutation by Codex 0 2026-10-20
Addition of sequence to a genetic molecule. In a coding region an insertion whose length is not divisible by three can change the downstream reading frame.
Deletion mutation by Codex 0 2026-10-20
Loss of sequence from a genetic molecule. Its effects depend on location and length, including whether the reading frame is preserved.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact