Define crossing over and explain when it occurs?

Answer 1

Crossing over allows daughter cells to be unique.
1
In genetics, traits that are usually linked, because they are caused by genes that are close together on the same chromosome, occasionally separate in offspring. This is called crossing-over, and is observed when geneticists are tracking traits in organisms.

2
In cytology, homologous chromosomes (e.g. the two copies of chromosome 7, or both copies of chromosome 12) can be seen to pair up during the first stage of meiosis (prophase I). The pair, which consists of two chromosomes and therefore a total of four chromatids, is called a bivalent. At a few points, typically three or four, along the bivalent, non-sister chromatids (i.e. one belonging to each of the two chromosomes), break and exchange segments. The place at which one of these breaks occurs is called a chiasma (plural chiasmata).

The cytological event (the exchange of corresponding segments of DNA between non-sister chromatids of a homologous pair of chromosomes) explains the genetic observation.

Answer 2

Crossing-over has two meanings, which refer to the same event.

1

In genetics, traits that are usually linked, because they are caused by genes that are close together on the same chromosome, occasionally separate in offspring. This is called crossing-over, and is observed when geneticists are tracking traits in organisms.

2

In cytology, homologous chromosomes (e.g. the two copies of chromosome 7, or both copies of chromosome 12) can be seen to pair up during the first stage of meiosis (prophase I). The pair, which consists of two chromosomes and therefore a total of four chromatids, is called a bivalent. At a few points, typically three or four, along the bivalent, non-sister chromatids (i.e. one belonging to each of the two chromosomes), break and exchange segments. The place at which one of these breaks occurs is called a chiasma.

The cytological event (the exchange of corresponding segments of DNA between non-sister chromatids of a homologous pair of chromosomes) explains the genetic observation.

Answer 3

Crossing Over Means Going To Heaven Which means Crossing over from the world to heaven i think that is what it means.

Answer 4

When Chromatids exchange genetic material in a process.

Answer 5

the exchange of genetic material between members of a homologous chromosome pair

Answer 6

It is a random exchange of genetic material between homologous chromosomes during the first phase fo meiosis. This is one source of variation in a population.

Answer 7

Crossing over is when non-sister chromatids of the homologous tetrad cross over and exchange pieces with one another. This occurs during prophase I of meiosis.