Table of Contents
Does meiosis produce polyploid cells?
Polyploidy is a condition in which the cells of an organism have more than two paired (homologous) sets of chromosomes. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis.
What happens during meiosis to produce a polyploid fertilized ovum?
What happens during meiosis to produce an polyploid? DNA replicates, but is not apportioned into daughter cells, forming a diploid gamete. Crossing over in the male yields unbalanced gametes, which can fertilize oocytes, but too much or too little genetic material halts development.
What happens during meiosis to produce an aneuploid?
Aneuploidy is caused by nondisjunction, which occurs when pairs of homologous chromosomes or sister chromatids fail to separate during meiosis. The loss of a single chromosome from a diploid genome is called monosomy (2n-1), while the gain of one chromosome is called trisomy (2n+1).
What causes Autopolyploid?
Autopolyploidization can occur when the pairs of homologous chromosomes have not separated into different nuclei during meiosis. The resulting gametes will be diploid rather than haploid.
What happens in polyploidy?
polyploidy, the condition in which a normally diploid cell or organism acquires one or more additional sets of chromosomes. If through polyploidy, however, the plant duplicates the chromosome set inherited from each parent, meiosis can occur, because each chromosome will have a homologue derived from its duplicate set.
What is the role of polyploidy?
Polyploidy is a major force in the evolution of both wild and cultivated plants. Some of the most important consequences of polyploidy for plant breeding are the increment in plant organs (“gigas” effect), buffering of deleterious mutations, increased heterozygosity, and heterosis (hybrid vigor).
What happens during nondisjunction in meiosis?
Nondisjunction occurs when homologous chromosomes or sister chromatids fail to separate during meiosis, resulting in an abnormal chromosome number.
Which of the following statements about the products produced when nondisjunction occurs during meiosis I is true?
Which of the following statements about the products produced when nondisjunction occurs during meiosis I is true? Nondisjunction during meiosis I yields two gametes that are missing a particular chromosome after meiosis II. The term applied to an individual with 25 chromosomes would be triploid. False.
What happens during G2 phase?
During the G2 phase, extra protein is often synthesized, and the organelles multiply until there are enough for two cells. Other cell materials such as lipids for the membrane may also be produced. With all this activity, the cell often grows substantially during G2.
How does meiosis contribute to genetic recombination?
When recombination occurs during meiosis, the cell’s homologous chromosomes line up extremely close to one another. Then, the DNA strand within each chromosome breaks in the exact same location, leaving two free ends. Each end then crosses over into the other chromosome and forms a connection called a chiasma.
What is the role of polyploidy in evolution?
Polyploidy is a major force in the evolution of both wild and cultivated plants. In some cases, when the crossing between two species is not possible because of differences in ploidy level, polyploids can be used as a bridge for gene transferring between them.
What is polyploidy discuss the role in evolution?
Polyploidy played a significant role in the origin and evolution of many plant species. The primary phylogenetic effect of polyploidy is to stabilize selected hybrid genotypes. It also provides a mechanism by which daughter and parental populations become. immediately isolated from each other.