When true-breeding or homozygous individuals that differ for a certain trait are crossed, all of the offspring will be heterozygotes for that trait. If the traits are inherited as dominant and recessive , the F 1 offspring will all exhibit the same phenotype as the parent homozygous for the dominant trait.
What is the explanation for why the F1 offspring all have the same phenotype the parent plants are true breeding?
When true-breeding or homozygous individuals that differ for a certain trait are crossed, all of the offspring will be heterozygotes for that trait. If the traits are inherited as dominant and recessive , the F 1 offspring will all exhibit the same phenotype as the parent homozygous for the dominant trait.
What happened when Mendel crossed a yellow seed plant with a green seed plant?
What happened when Mendel crossed a yellow pea plant with a green pea plant? Mendel crossed true-breeding plants having yellow peas with plants having green peas. The resulting plant had all yellow peas. An F1 cross resulted in 3/4ths of the plants having yellow peas and 1/4th of the plants having green peas .
What is the F1 generation when a pea plant with yellow seeds is crossed with a pea plant that is heterozygous for the allele and has green seeds?
A pea plant with yellow seeds was crossed with a pea plant with green seeds. Explain why green seeds reappeared in the F2 generation. The parent generation are both “true breeding”, or homozygous. When you cross them, the F1 generation is all heterozygous .
What is the phenotypic ratio of the offspring?
The phenotypic ratio is the distribution pattern (expressed as a ratio) of the physical characteristics in the offspring obtained after a genetic cross . So, genotypic ratio and phenotypic ratio are the two types of genetic ratios used to express the genotype and the phenotype of offspring from a genetic cross.
Is a true-breeding plant homozygous?
The sperm and the eggs that produce the next generation of plants both come from the same parent. ... The result is highly inbred, or “true-breeding,” pea plants. These are plants that always produce offspring that look like the parent. Today, we know that these “true-breeding” plants are homozygous for most traits .
What is the percentage of a homozygous dominant offspring?
| PARENT GENOTYPES OFFSPRING PHENOTYPES | pure (homozygous) dominant x anything 100% of offspring with dominant trait | hybrid x homozygous recessive 50% dominant trait, 50% recessive trait | hybrid x hybrid 75% with dominant trait & 25% with recessive trait | homozygous recessive x homozygous recessive 100% recessive trait |
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What happens when two heterozygous yellow seeded plants are crossed?
Plants with two different alleles of a gene are heterozygous. Since all the heterozygous offspring are yellow, then the yellow allele must be dominant over the recessive green allele. ... When two heterozygous plants are crossed, the resulting progeny mostly show the dominant phenotype .
Are yellow seeds dominant or recessive?
Seed color is governed by a single gene with two alleles. The yellow-seed allele is dominant and the green-seed allele is recessive. When true-breeding plants were cross-fertilized, in which one parent had yellow seeds and one had green seeds, all of the F 1 hybrid offspring had yellow seeds.
What is an example of Mendelian inheritance?
A Mendelian trait is one that is controlled by a single locus in an inheritance pattern. In such cases, a mutation in a single gene can cause a disease that is inherited according to Mendel’s principles. ... Examples include sickle-cell anemia, Tay–Sachs disease, cystic fibrosis and xeroderma pigmentosa .
Is FF homozygous or heterozygous?
| Genotype Phenotype | F F Homozygous dominant No cystic fibrosis (Normal) | F f Heterozygous Carrier (has no symptoms but carries the recessive allele) | f f Homozygous recessive Cystic fibrosis (has symptoms) |
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Is TT a heterozygous or homozygous?
| Genotype Symbol Genotype Vocab Phenotype | TT homozygous DOMINANT or pure tall tall | Tt heterozygous or hybrid tall | tt homozygous RECESSIVE or pure short short |
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Is AA homozygous or heterozygous?
If an organism has two copies of the same allele, for example AA or aa, it is homozygous for that trait. If the organism has one copy of two different alleles, for example Aa, it is heterozygous. Keep in mind that an organism can’t simply be ‘homozygous,’ period.
Is PP genotype or phenotype?
A simple example to illustrate genotype as distinct from phenotype is the flower colour in pea plants (see Gregor Mendel). There are three available genotypes, PP ( homozygous dominant ), Pp (heterozygous), and pp (homozygous recessive).
What cross will result in a 1 2 1 genotype ratio in the offspring?
Tutorial. A cross of two F1 hybrids , heterozygous for a single trait that displays incomplete dominance is predicted to give a 1:2:1 ratio among both the genotypes and phenotypes of the offspring.
What is phenotype and example?
The term “phenotype” refers to the observable physical properties of an organism ; these include the organism’s appearance, development, and behavior. ... Examples of phenotypes include height, wing length, and hair color.
