What does nucleus mean?
Word: Nucleus
Part of Speech: Noun
Meaning: Nucleus means the central part of something. In a living cell, the nucleus is the part that controls the cell; in an atom, it is the tiny centre made of protons and neutrons.
Synonyms: centre, heart
How do you spell nucleus?
Syllables: nu - cle - us
Tricky part: The start is nu, with no e before the u, just as in nuclear. Neucleus is a common slip.
Watch out for: neucleus, newcleus
Memory tip: Nucleus and nuclear begin the same way, so start it exactly as you start nuclear.
Nucleus in a sentence
Example 1: Under the microscope, we could see a dark nucleus in each onion cell.
Example 2: The nucleus of a comet is a ball of ice and dust only a few kilometres across.
Example 3: A small group of keen players formed the nucleus of the new school team.
Fun Fact
The Scottish botanist Robert Brown named the cell nucleus in the early 1830s after studying cells from orchid leaves.
Practise the CREST Way
Spell-o-Spell
Choose the correctly spelt word:
a) nucleus
b) cytoplasem
c) membrain
d) chromosone
Show answer
a) nucleus. Cytoplasm has no e before m, membrane ends in ane, and chromosome ends in some.
Mingle-Mangle
Form a meaningful word from the jumbled letters:
sulecun
a) nuclear
b) unclear
c) nucleus
d) uncles
Show answer
c) nucleus. Nuclear and unclear both need an a and an r, and uncles is one u short.
Word Cookie
Find the misspelt word in the sentence:
Our science teacher asked us to colour the nucleas of each cell in the diagram with a blue pencil.
a) nucleas
b) diagram
c) colour
d) science
Show answer
a) nucleas. The ending has a u before the s: nu-cle-us.
Word Connection
Choose the synonym of the word: nucleus
a) edge
b) core
c) shell
d) surface
Show answer
b) core. The nucleus is the core, the part right at the centre.
Multiple Choice Questions
1. Which of these cells has no nucleus once it is fully formed?
a) an onion peel cell
b) a green leaf cell
c) a human red blood cell
d) a human cheek cell
Show answer
c) a human red blood cell
2. Which scientist showed in 1911 that an atom has a tiny nucleus at its centre?
a) Isaac Newton
b) Charles Darwin
c) Louis Pasteur
d) Ernest Rutherford
Show answer
d) Ernest Rutherford
