Examples of gamete in the following topics:
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- If homologous chromosomes fail to separate during meiosis I, the result is two gametes that lack that particular chromosome and two gametes with two copies of the chromosome.
- If sister chromatids fail to separate during meiosis II, the result is one gamete that lacks that chromosome, two normal gametes with one copy of the chromosome, and one gamete with two copies of the chromosome .
- If a gamete with two copies of the chromosome combines with a normal gamete during fertilization, the result is trisomy; if a gamete with no copies of the chromosomes combines with a normal gamete during fertilization, the result is monosomy.
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- For example, if a plant species with 2n = 6 produces autopolyploid gametes that are also diploid (2n = 6, when they should be n = 3), the gametes now have twice as many chromosomes as they should have.
- These new gametes will be incompatible with the normal gametes produced by this plant species.
- Therefore, an allopolyploid occurs when gametes from two different species combine .
- In the example shown, a normal gamete from one species fuses with a polyploidy gamete from another.
- Aneuploidy results when the gametes have too many or too few chromosomes due to nondisjunction during meiosis.
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- Once the haploid gametes are formed, they lose the ability to divide again.
- Meiosis is not directly involved in the production of gametes because the organism that produces the gametes is already a haploid.
- Fertilization between the gametes forms a diploid zygote.
- In animals, sexually-reproducing adults form haploid gametes from diploid germ cells.
- Fusion of the gametes gives rise to a fertilized egg cell, or zygote.
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- In essence, the law states that copies of genes separate or segregate so that each gamete receives only one allele.
- The behavior of homologous chromosomes during meiosis can account for the segregation of the alleles at each genetic locus to different gametes.
- As chromosomes separate into different gametes during meiosis, the two different alleles for a particular gene also segregate so that each gamete acquires one of the two alleles.
- The Law of Segregation states that alleles segregate randomly into gametes
- When gametes are formed, each allele of one parent segregates randomly into the gametes, such that half of the parent's gametes carry each allele.
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- If one homologous chromosome has alleles for tall plants and red flowers, and the other chromosome has genes for short plants and yellow flowers, then when the gametes are formed, the tall and red alleles will go together into a gamete and the short and yellow alleles will go into other gametes.
- These are called the parental genotypes because they have been inherited intact from the parents of the individual producing gametes.
- But unlike if the genes were on different chromosomes, there will be no gametes with tall and yellow alleles and no gametes with short and red alleles.
- If you create the Punnett square with these gametes, you will see that the classical Mendelian prediction of a 9:3:3:1 outcome of a dihybrid cross would not apply.
- Geneticists have used the proportion of recombinant gametes (the ones not like the parents) as a measure of how far apart genes are on a chromosome.
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- The evolution of seeds allowed plants to reproduce independently of water; pollen allows them to disperse their gametes great distances.
- Male gametes reach female gametophyte and the egg cell gamete though a pollen tube: an extension of a cell within the pollen grain.
- The sperm of modern gymnosperms lack flagella, but in cycads and the Gingko, the sperm still possess flagella that allow them to swim down the pollen tube to the female gamete; however, they are enclosed in a pollen grain.
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- Because each parent is homozygous, the law of segregation indicates that the gametes for the green/wrinkled plant all are yr, while the gametes for the yellow/round plant are all YR.
- For the F2 generation, the law of segregation requires that each gamete receive either an R allele or an r allele along with either a Y allele or a y allele.
- The law of independent assortment states that a gamete into which an r allele sorted would be equally likely to contain either a Y allele or a y allele.
- Thus, there are four equally likely gametes that can be formed when the YyRr heterozygote is self-crossed as follows: YR, Yr, yR, and yr.
- Arranging these gametes along the top and left of a 4 × 4 Punnett square gives us 16 equally likely genotypic combinations.
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- Chytrids are the most primitive group of fungi and the only group that possess gametes with flagella.
- Their gametes are the only fungal cells known to have a flagellum.
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- The sorting of chromosomes from each homologous pair into pre-gametes appears to be random.
- Each parent synthesizes gametes that contain only half of their chromosomal complement.
- Even though male and female gametes (sperm and egg) differ in size and morphology, they have the same number of chromosomes, suggesting equal genetic contributions from each parent.
- The gametic chromosomes combine during fertilization to produce offspring with the same chromosome number as their parents.
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- Meiosis is the division of the contents of the nucleus, dividing the chromosomes among gametes.
- The process of meiosis produces unique reproductive cells called gametes, which have half the number of chromosomes as the parent cell.
- Fertilization, the fusion of haploid gametes from two individuals, restores the diploid condition.
- In animals, sexually-reproducing adults form haploid gametes from diploid germ cells.
- Fusion of the gametes gives rise to a fertilized egg cell, or zygote.