tetrad (redirected from Fallot's tetrad)

tet·rad  (ttrd)

n.

1. A group or set of four.

2. A tetravalent atom, radical, or element.

3. Biology

a. A four-part structure that forms during the prophase of meiosis and consists of two homologous chromosomes, each composed of two sister chromatids.

b. Botany A group of four cells, as of spores or pollen grains, formed by division of one mother cell.

---

[Greek tetras, tetrad-; see k^wetwer- in Indo-European roots.]

---

te·tradic adj.

---

tetrad [ˈtɛtræd]

n

1. (Mathematics) a group or series of four

2. (Mathematics) the number four

3. (Life Sciences & Allied Applications / Biology) Botany a group of four cells formed by meiosis from one diploid cell

4. (Life Sciences & Allied Applications / Genetics) Genetics a four-stranded structure, formed during the pachytene stage of meiosis, consisting of paired homologous chromosomes that have each divided into two chromatids

5. (Chemistry) Chem an element, atom, group, or ion with a valency of four

6. (Life Sciences & Allied Applications / Environmental Science) Ecology a square of 2 ✕ 2 km used in distribution mapping

[from Greek tetras, from tettares four]

---

tetrad  (ttrd)

1. A four-part structure that forms during prophase I of meiosis and consists of two homologous chromosomes, each composed of two identical chromatids. During prophase I of meiosis, one chromosome exchanges corresponding segments of genetic material with the other chromosome in the tetrad in the process called crossing over. See more at meiosis.

2. A group of four cells, as of spores or pollen grains, formed from a parent cell by meiosis. As part of the process of spermatogenesis, a spermatocyte divides into a tetrad of four spermatids, cells which go on to develop into sperm. See more at spermatogenesis.

---

Tetrad a group of four; four things regarded together as a single object or thought.

Example: Great Tetrad of senior wranglers, 1898.

Thesaurus

Noun

1.

tetrad - the cardinal number that is the sum of three and one IV, Little Joe, quadruplet, quartet, quatern, 4, four, quaternion, quaternity, foursome, quaternary digit, figure - one of the elements that collectively form a system of numeration; "0 and 1 are digits"