karyogamy

C2 / Very Low Frequency / Specialist
UK/ˌkærɪˈɒɡəmi/US/ˌkɛriˈɑːɡəmi/

Highly technical/scientific; used almost exclusively in biology, mycology, and cell biology contexts.

My Flashcards

Definition

Meaning

The fusion of two cell nuclei, especially as the second stage of syngamy (fertilization) following plasmogamy.

In biology, the process during sexual reproduction where the nuclei of two gametes (such as an egg and a sperm) merge to form a single diploid nucleus, combining their genetic material. It is a crucial step in eukaryotic reproduction.

Linguistics

Semantic Notes

Specifically denotes nuclear fusion, not just cellular fusion. Often contrasted with 'plasmogamy' (cytoplasmic fusion). Central to understanding sexual life cycles in fungi, algae, and protists.

Dialectal Variation

British vs American Usage

Differences

No significant differences in meaning or usage. Spelling is identical.

Connotations

Purely technical, with no regional connotations.

Frequency

Equally rare and specialist in both varieties.

Vocabulary

Collocations

strong
following plasmogamynuclear fusionduring fertilizationhaploid nuclei undergo
medium
delayed karyogamycomplete karyogamykaryogamy occursprecedes karyogamy
weak
process of karyogamystage of karyogamykaryogamy and plasmogamy

Grammar

Valency Patterns

Karyogamy follows plasmogamy.The two haploid nuclei undergo karyogamy.Karyogamy results in a diploid zygote nucleus.

Vocabulary

Synonyms

Neutral

nuclear fusion

Weak

nucleogamy

Vocabulary

Antonyms

karyokinesis (nuclear division)plasmogamy (when contrasted as a separate step)

Usage

Context Usage

Business

Not used.

Academic

Used in advanced biology textbooks and research papers on cell reproduction, mycology, and genetics.

Everyday

Virtually never used.

Technical

Core term in cell biology and mycology to describe a specific phase of sexual reproduction.

Examples

By Part of Speech

noun

British English

  • In yeast, karyogamy is a tightly regulated process.
  • The delay between plasmogamy and karyogamy can be considerable in some fungi.

American English

  • Karyogamy was observed under the microscope following fertilization.
  • The textbook diagram clearly labeled the stage of karyogamy.

Examples

By CEFR Level

B2
  • Sexual reproduction in many fungi involves two distinct steps: plasmogamy and karyogamy.
C1
  • The molecular mechanisms that regulate karyogamy in budding yeast involve specific proteins that mediate nuclear congression and membrane fusion.

Learning

Memory Aids

Mnemonic

Think: 'CARRY the GAMetes' together (karyo-gamy). KARYO (nucleus) + GAMY (marriage/union) = marriage of nuclei.

Conceptual Metaphor

NUCLEI ARE PARTNERS IN MARRIAGE. The process is framed as a union or marriage of two nuclei.

Watch out

Common Pitfalls

Translation Traps (for Russian speakers)

  • Do not confuse with 'кариогамия' (direct cognate, same meaning). Trap: mistaking it for a more general term like 'оплодотворение' (fertilization), which is broader. Karyogamy is a specific sub-process.

Common Mistakes

  • Using it to mean general cell fusion. Confusing it with 'syngamy' (which can encompass both plasmogamy and karyogamy). Misspelling as 'caryogamy' (less common variant).

Practice

Quiz

Fill in the gap
In the sexual cycle of ascomycete fungi, , the fusion of the nuclei, typically occurs long after plasmogamy.
Multiple Choice

What is the direct result of karyogamy?

FAQ

Frequently Asked Questions

No, not exactly. Fertilization (syngamy) is the broader process of gamete fusion, which often includes both plasmogamy (cytoplasmic fusion) and karyogamy (nuclear fusion). Karyogamy is a key part of fertilization.

It is a central concept in the life cycles of fungi (e.g., yeast, mushrooms), some algae, and protists, where plasmogamy and karyogamy are often temporally separated events.

In terms of the nuclear cycle, the opposite would be meiosis (reduction division) or karyokinesis (division of a nucleus). In the context of the mating process, the preceding step, plasmogamy, is often contrasted with it.

Yes, in biological research, mutants are known where plasmogamy occurs but karyogamy fails, resulting in cells with two separate nuclei (dikaryons). This is often studied to understand the genes controlling nuclear fusion.