What happens when homologous chromosomes cross over quizlet?
When homologous chromosomes crossover, what occurs? A) Two chromatids get tangled, resulting in one re-sequencing its DNA.
What happens during crossover in meiosis?
Crossing over is the swapping of genetic material that occurs in the germ line. During the formation of egg and sperm cells, also known as meiosis, paired chromosomes from each parent align so that similar DNA sequences from the paired chromosomes cross over one another.
When homologous chromosomes pair together tightly in meiosis I it is called quizlet?
Each chromosome comprises two sister chromatids, joined at the centromere. Sister chromatids are formed by DNA replication in the S phase of interphase before meiosis begins. … Homologous chromosomes are paired up to form bivalents in a process called synapsis. Sister chromatids are tightly associated.
What occurs during crossing over quizlet?
Crossing over occurs during prophase I of meiosis I. It involves the switching of genes between homologues non-sister chromatids which allows the mixture of maternal and paternal genetic material with new, recombinant chromosomes. … Three events unique to meiosis I that do not occur in mitosis.
What happens during crossover?
Crossing over is a process that happens between homologous chromosomes in order to increase genetic diversity. During crossing over, part of one chromosome is exchanged with another. The result is a hybrid chromosome with a unique pattern of genetic material.
Do chromosomes crossover during mitosis?
The stages of mitosis are prophase, metaphase, anaphase, and telophase. … No, homologous chromosomes act independently from one another during alignment in metaphase and chromatid segregation in anaphase. Does crossing over occur? No, because chromosomes do not pair up (synapsis), there is no chance for crossing over.
Which best explains why the crossing over of two homologous chromosomes occurs?
Q. Which best explains why the crossing over of two homologous chromosomes occurs? … Chromosomes in the next generation will be less stable because crossovers will occur during meiosis but not mitosis. Because meiosis produces fewer viable cells than mitosis, organisms made with cells from meiosis will be less healthy.
Which chromosomes are involved in crossing over?
Crossing over occurs between prophase I and metaphase I and is the process where two homologous non-sister chromatids pair up with each other and exchange different segments of genetic material to form two recombinant chromosome sister chromatids.
How does segregation happen during anaphase 2?
There are two ways in which non-disjunction can occur: 1) both homologous chromosomes migrate together to one pole instead of separating to opposite poles in Anaphase I or 2) sister chromatids fail to separate properly and both sister chromatids move together to one pole instead of to opposite poles in Anaphase II.