nuc
leus
Plural
nuclei
1
(biology) the part of a cell that contains most of the genetic information
- The nucleus of a cell contains genetic material in the form of DNA, which regulates cellular activities.
- The nucleus is surrounded by a double membrane called the nuclear envelope, which controls the passage of materials into and out of the nucleus.
- Within the nucleus, there is a dense region called the nucleolus, where ribosomal RNA (rRNA) is synthesized and assembled into ribosomes.
- The nucleus plays a crucial role in cell division, as it coordinates the replication and distribution of genetic material to daughter cells.
- Mutations in genes within the nucleus can lead to genetic disorders and diseases, affecting the normal function of cells and tissues.
Synonyms:
2
a central or most important group within a larger organization, often responsible for leadership or key decisions
- The nucleus of the team consisted of senior engineers who led the development process.
- The political nucleus of the movement pushed for major reforms in the education system.
- The nucleus of the project team worked around the clock to meet the deadline.
- The nucleus of the committee met regularly to discuss the organization's future direction.
- The company's nucleus of innovative thinkers helped shape its cutting-edge technology.
Synonyms:
3
the dense, positively charged core of an atom, made up of protons and neutrons and containing most of the atom's mass
- The nucleus contains nearly all the mass of an atom.
- Scientists studied how electrons orbit the atomic nucleus.
- The fusion of two nuclei releases enormous amounts of energy.
- Radioactive decay alters the composition of an unstable nucleus.
- Hydrogen has the simplest nucleus, consisting of only one proton.
4
a distinct cluster of nerve cells within the brain or spinal cord that performs a specific function
- The hypothalamic nucleus regulates hunger and body temperature.
- Damage to the caudate nucleus can affect movement control.
- Neural signals pass through the cochlear nucleus before reaching the brainstem.
- Researchers mapped the nucleus responsible for emotional processing.
- Each nucleus in the brainstem has a specialized sensory or motor role.
5
the dense central region of the eye's lens, surrounded by the softer cortex
- The lens nucleus becomes cloudy with age, leading to cataracts.
- The surgeon carefully removed the hardened nucleus during the procedure.
- In young eyes, the lens nucleus remains soft and flexible.
- The outer cortex protects the inner nucleus of the lens.
- The opacity was limited to the nucleus, sparing the lens periphery.
Synonyms:
6
the central core of a comet, which is composed of ice, dust, and rocky materials
- The nucleus of Comet Hale-Bopp is believed to be several kilometers in diameter.
- The nucleus of a comet contains volatile substances that vaporize when the comet approaches the Sun, creating its characteristic tail.
- The nucleus of Comet Halley is thought to be a mixture of water ice, carbon dioxide ice, and various organic compounds.
- As a comet approaches the Sun, the heat causes the nucleus to release gas and dust, forming a glowing coma and tail.
- The nucleus of Comet Wild 2 was probed by the Stardust mission, which collected samples that offered clues about the origins of our solar system.
7
the central sound unit of a syllable, usually formed by a vowel or vowel-like element, around which other sounds cluster
A nucleus is the central part of a syllable, usually consisting of a vowel sound. It serves as the core around which the rest of the syllable is built, and it is essential for the syllable's structure. For example, in the word "cat," the nucleus is the "a" sound, while in "beat," the nucleus is the "ea" sound. The nucleus is important in phonetics because it contributes to the overall sound and rhythm of speech, playing a key role in how syllables are formed and how words are pronounced in various languages.
- In the word "cat," the vowel /æ/ serves as the syllable's nucleus.
- Every syllable must have a nucleus to be pronounceable.
- The linguist analyzed how nasals can occasionally act as syllable nuclei.
- Stress typically falls on the nucleus of the syllable in English words.
- The nucleus distinguishes syllabic peaks from surrounding consonants.