Table of Contents
If they have white flowers, then they are homozygous recessive (white-white). Carriers are always heterozygous. People with CF are homozygous recessive. Since Huntington’s disease is autosomal dominant, people with the disease can be either homozygous dominant or heterozygous.
Are purple flowers dominant or recessive?
Explore Trait Dominant Expression Recessive Expression Color of seed albumen (Y) Yellow Green Color of flower (P) Purple White Form of ripe pods (I) Inflated Constricted Color of unripe pods (G) Green Yellow.
Is white or purple dominant?
These are the parental generation. Their offspring—the first filial, or F1, generation—each receive one purple allele and one white allele. Since all of the offspring have the purple phenotype, this tells us that the purple allele is dominant to the white allele.
Are white flowers on pea plants a dominant trait?
Terms in this set (10) From those results, Mendel concluded that white flowers on pea plants are a dominant trait. Mendel began his experiments with pea plants that stayed the same from one generation to the next. In those same experiments, about three-fourths of the second-generation crosses had white flowers.
Are blue flowers dominant or recessive?
In plant species #1, the three genes are linked and located on chromosome 1 the gene order is B-T-F, and each interval is 1 cM. Blue flower color is dominant, so in a cross between two heterozygotes, 3/4 of the progeny will produce blue flowers.
Could two white flowers produce plants with purple flowers?
Can two plants with purple flowers produce offspring with white flowers? Yes, if both parents are heterozygous for the trait. You just studied 36 terms!.
Are yellow seeds dominant or recessive?
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 F1 hybrid offspring had yellow seeds.
Which flower color is recessive?
The recessive trait does, however, reappear in the progeny of the hybrid offspring. An example of a dominant trait is the violet-colored flower trait. For this same characteristic (flower color), white-colored flowers are a recessive trait.
Why did Mendel see a 3 1 ratio of purple to white flowers in the F2 cross?
Traits are inherited independently Mendel also experimented to see what would happen if plants with 2 or more pure-bred traits were cross-bred. He found that each trait was inherited independently of the other and produced its own 3:1 ratio. This is the principle of independent assortment.
Why are there more purple flowers than white flowers in the 3rd generation?
Why was there a 3:1 ratio of purple:white in the next generation (the F2)? From AS: Q1 = In the F1 generation the white pea flower was “masked”, which resulted in the appearance of all purple flowers. Because of this each of the offspring in the F1 generation were all heterozygous making them purple.
What are dominant recessive traits?
Dominant and recessive traits exist when a trait has two different forms at the gene level. The trait that first appears or is visibly expressed in the organism is called the dominant trait. The trait that is present at the gene level but is masked and does not show itself in the organism is called the recessive trait.
What determines a pea plants characteristics?
The characteristics included plant height, seed texture, seed color, flower color, pea-pod size, pea-pod color, and flower position.
Why did the F1 generation showed all flowers to be purple rather than a mix of white and purple flowers?
Mendel discovered that by crossing true-breeding white flower and true-breeding purple flower plants, the result was a hybrid offspring. Rather than being a mix of the two colors, the offspring was purple flowered. The resulting hybrids in the F1 generation all had violet flowers.
What phenotypes would be possible?
There are four different phenotypes possible: A, B, AB, and O. The alleles A and B are codominant, and the O allele is recessive to both A and B. a.
What are the two possible phenotypes for flower color?
An organism’s genotype is its specific combination of alleles for a given gene. So, for example, in the pea plants above, the possible genotypes for the flower-color gene were red-red, red-white, and white-white. The phenotype is the physical manifestation of an organism’s allellic combination (genotype).
What are the 5 patterns of inheritance?
There are five basic modes of inheritance for single-gene diseases: autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, and mitochondrial. Genetic heterogeneity is a common phenomenon with both single-gene diseases and complex multi-factorial diseases.
What happened when Mendel crossed true-breeding purple flowers with white flowers?
Mendel noted that hybridizing true-breeding (P generation) plants gave rise to an F1 generation that showed only one trait of a characteristic. For example, a true-breeding purple-flowering plant crossed with a true-breeding white-flowering plant always gave rise to purple-flowered hybrid plants.
What happens when a true-breeding purple flower pea plant is crossed with a true-breeding white flower pea plant?
You cross a “true-breeding” purple flowered, tall pea plant (PPTT) with a “true-breeding” white flowered, dwarf pea plant (pptt) and you get 100% purple, tall pea plants in your F1 generation. Both parent plants are “true breeding” and all of the F1 offspring have purple flowers and round seeds.
What is the probability that a cross between a plant that is heterozygous for purple flowers PP with a flower that is homozygous recessive for white flowers PP will produce a plant with white flowers?
Checking the probability of fusion between the gametes produced by two plants crossed using Punnet Square method, it is seen that 75% plants will have at least one dominant allele (P) and thus will bear purple flowers. Only 25% plants will have recessive allele in homozygous state (pp).
What happens if you cross two heterozygotes?
When two heterozygous plants are crossed, the resulting progeny mostly show the dominant phenotype. But, the recessive phenotype reappears.
Are round seeds dominant or recessive?
In pea plants, round seeds are dominant and wrinkled seeds are recessive.
Why is pea yellow?
Fusarium wilt, root rot, Ascochyta blight, and downy mildew are all fungi that may afflict these crops and result in yellowing pea plants. Pea plants yellow at the base of the plant and stems wither and eventually die back. Spores are dispersed through contact, wind, and water.
Why did the white flower color disappear in the F1 generation?
Instead, Mendel’s results demonstrated that the white flower trait had completely disappeared in the F1 generation. This is called a reciprocal cross—a paired cross in which the respective traits of the male and female in one cross become the respective traits of the female and male in the other cross.
What is the genotype for a pink flower?
The genotype for the pink flower is RW, and the genotype for the white flower is WW. This would lead to a 50% chance of the offspring having a phenotype of pink.
When red and white flowers are crossed pink flowers are produced?
Explanation: Incomplete dominance is an example of a non-mendelian trait (doesn’t follow the genetic rules established by Gregor Mendel). When two parents mate and produce offspring, the offspring is a blend of the two parents. So, a red flower and a white flower would make a pink flower.
