Examples of true-breeding plant in the following topics:
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- The result is highly inbred, or "true-breeding," pea plants.
- Today, we know that these "true-breeding" plants are homozygous for most traits.
- When Mendel cross-pollinated a true-breeding plant that only produced yellow peas with a true-breeding plant that only produced green peas, he found that the first generation of offspring is always all yellow peas.
- In this and all the other pea plant traits Mendel followed, one form of the trait was "dominant" over another so it masked the presence of the other "recessive" form in the first generation after cross-breeding two homozygous plants..
- By experimenting with true-breeding pea plants, Mendel avoided the appearance of unexpected (recombinant) traits in offspring that might occur if the plants were not true breeding.
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- Mendel crossed or mated two true-breeding (self-pollinating) garden peas, Pisum saivum, by manually transferring pollen from the anther of a mature pea plant of one variety to the stigma of a separate mature pea plant of the second variety.
- When true-breeding plants in which one parent had white flowers and one had violet flowers were cross-fertilized, all of the F1 hybrid offspring had violet flowers .
- That is, the hybrid offspring were phenotypically identical to the true-breeding parent with violet flowers.
- First, Mendel confirmed that he had plants that bred true for white or violet flower color.
- In one of his experiments on inheritance patterns, Mendel crossed plants that were true-breeding for violet flower color with plants true-breeding for white flower color (the P generation).
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- Mendel's crosses involved mating two true-breeding organisms that had different traits to produce new generations of pea plants.
- Mendel performed crosses, which involved mating two true-breeding individuals that have different traits .
- In the pea, which is a naturally self-pollinating plant, this is done by manually transferring pollen from the anther of a mature pea plant of one variety to the stigma of a separate mature pea plant of the second variety.
- Plants used in first-generation crosses were called P0, or parental generation one, plants.
- In one of his experiments on inheritance patterns, Mendel crossed plants that were true-breeding for violet flower color with plants true-breeding for white flower color (the P generation).
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- Between 1856 and 1863, he cultivated and tested some 28,000 pea plants.
- He described these laws in a two part paper, "Experiments on Plant Hybridization", which was published in 1866.
- Mendel discovered that by crossing true-breeding white flower and true-breeding purple flower plants, the result was a hybrid offspring.
- He did this by cross-breeding dihybrids; that is, plants that were heterozygous for the alleles controlling two different traits.
- In one of his experiments on inheritance patterns, Mendel crossed plants that were true-breeding for violet flower color with plants true-breeding for white flower color (the P generation).
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- When fertilization occurs between two true-breeding parents that differ in only one characteristic, the process is called a monohybrid cross, and the resulting offspring are monohybrids.
- To demonstrate a monohybrid cross, consider the case of true-breeding pea plants with yellow versus green pea seeds.
- For a monohybrid cross of two true-breeding parents, each parent contributes one type of allele.
- Called the test cross , this technique is still used by plant and animal breeders.
- In the P generation, pea plants that are true-breeding for the dominant yellow phenotype are crossed with plants with the recessive green phenotype.
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- Observing that true-breeding pea plants with contrasting traits gave rise to F1 generations that all expressed the dominant trait and F2 generations that expressed the dominant and recessive traits in a 3:1 ratio, Mendel proposed the law of segregation.
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- An example of a genetic event is a round seed produced by a pea plant.
- Mendel demonstrated that the probability of the event "round seed" was guaranteed to occur in the F1 offspring of true-breeding parents, one of which has round seeds and one of which has wrinkled seeds.
- Mendel demonstrated that the pea-plant characteristics he studied were transmitted as discrete units from parent to offspring.
- For instance, performing a cross between a plant with green, wrinkled seeds and a plant with yellow, round seeds produced offspring that had a 3:1 ratio of green:yellow seeds and a 3:1 ratio of round:wrinkled seeds.
- Calculate the probability of traits of pea plants using Mendelian crosses
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- The independent assortment of genes can be illustrated by the dihybrid cross: a cross between two true-breeding parents that express different traits for two characteristics.
- Consider the characteristics of seed color and seed texture for two pea plants: one that has green, wrinkled seeds (yyrr) and another that has yellow, round seeds (YYRR).
- 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.
- This dihybrid cross of pea plants involves the genes for seed color and texture.
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- Most familiar animals and some plants have paired chromosomes and are described as diploid.
- The recessive trait will only be expressed by offspring that have two copies of this allele; these offspring will breed true when self-crossed.
- Since Mendel's experiments with pea plants, other researchers have found that the law of dominance does not always hold true.
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- Today's crops are a result of plant breeding, which employs artificial selection to produce the present-day cultivars.
- An example is modern corn, which is a result of thousands of years of breeding that began with its ancestor, teosinte.
- Self-pollination leads to the production of plants with less genetic diversity since genetic material from the same plant is used to form gametes and, eventually, the zygote.
- Many plants, such as cucumbers, have male and female flowers located on different parts of the plant, thus making self-pollination difficult.
- Other plant species are pollinated by abiotic agents, such as wind and water.