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Biology vocabulary · Cells and Levels of Organization

Nucleus

Meaning in biology, with examples

/ˈnuːkliəs/nounCore term

In biology, nucleus means: The large structure in a eukaryotic cell that holds most of its DNA and controls the cell's activities. It is surrounded by a double membrane called the nuclear envelope.

In Turkish: çekirdek, nükleus

How it is used

The plural is nuclei (/ˈnuːkliaɪ/). The adjective nuclear appears in nuclear DNA, nuclear envelope and nuclear pore. Prokaryotes such as bacteria have no nucleus; their DNA lies in a region called the nucleoid.

Example sentences

  1. The nucleus was stained blue with DAPI.

  2. Most cells have a single nucleus, but skeletal muscle fibers contain hundreds of nuclei.

Common collocations

  • cell nucleus
  • nuclear envelope
  • nuclear DNA
  • stain the nucleus
  • cellThe smallest unit of life that can survive on its own. Every living thing is made of one or more cells, and each cell is surrounded by a membrane.
  • eukaryoteAn organism whose cells have a true nucleus and membrane-bound organelles. Animals, plants, fungi and protists are all eukaryotes.
  • DNAShort for deoxyribonucleic acid, the molecule that stores genetic information in every cell and in many viruses. It is made of two strands twisted into a double helix.
  • chromosomeA long, tightly packed structure of DNA and proteins that carries many genes. Human body cells normally have 46 chromosomes, arranged in 23 pairs.
  • organelleA small structure inside a cell that has a specific job, such as the nucleus, mitochondria or chloroplasts. Most organelles are surrounded by their own membrane.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Cells and Levels of Organization

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