what is a tetrad? during which stage of meiosis is it formed?

Answer 1

There are two definitions
A tetrad is the association of a group of four sister chromatids in an early stage of meiosis. So this will occur between the zygotena to the diplotena stage of prophase 1, where the two pairs of sister chromatids are aligned together, also known as bivalents.
A tetrad is also a group of four fungal spores contained in an ascus.

Answer 2

Tetrad Meiosis

Answer 3

Prophase I : The nucleus disappears, spindle fibers form , and the chromatid pairs form. A major difference occurs here separating this prophase from mitosis prophase. The chromatid pairs pair up with their homologous pair, forming a tetrad. This tetrad contains 2 original homologous chromosomes and their duplicates. The process of crossing over occurs during this time allowing for genetic diversity in the genome. Crossing over is a process where pieces of two homologous chromosomes, switch places and end up on the other chromosome. (1 cell )

Metaphase I : Tetrads line up along the center of the cell. (1 cell )

Anaphase I : The tertads split and move in opposite directions. During this phase the chromatid pairs move away from each other. (1 cell )

Answer 4

A tetrad is formed when a pair of double-stranded homologous chromosomes line up together (an action called synapsing). This matching of chromosomes happens during prophase I of meiosis.