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What kind of offspring will a homozygous tall plant and a homozygous short plant have?
Presuming tall is a dominant allele (the 2nd parent is heterozygous and "tall" is it's phenotype), then the square would be as follows:
Let T be the dominant gene for tall, and thus every genotype containing this (TT, or Tt) would produce a tall plant.
Let t be recessive, and in the absence of T (tt) causes a plant to be small.
So the homozygous tall parent would be TT, and the heterozygous tall parent would be Tt.
So now you just have to cross them. During meiosis, every gamete from the TT genotype would contain a T allele. However, for the Tt genotype, there is equal chance each gamete will contain EITHER a T or a t.
So the square would be:
xxTxxT
TxTTxTT
txTtxTt
As you can see, 2 out of the 4 offspring have a Tt genotype (heterozygous), so this translates to a 1/2 fraction, or 50%.
Ignore the Xs in the table- if i just used spaces then all the letters crunched up on top of each other when i pressed save...it was the best i could do...:S
What else can I help you with?
To perform a testcross scientists cross an organism with an unknown genotype with what kind of organism?
To perform a testcross, scientists cross the organism with an unknown genotype with a homozygous recessive organism. This allows researchers to determine the unknown genotype based on the phenotypic ratios observed in the offspring.
What is the difference between a Pure tall plant and hybrid tall plant?
A pure tall plant refers to one that has been consistently bred with other tall plants of the same variety to maintain its tall characteristics. A hybrid tall plant, on the other hand, results from cross-breeding two different varieties of plants to create a new plant with varying characteristics, such as height.
What is true breeding?
Purebred organisms are the organisms in the off springs for many generations which have the same traitA true-breeding organism, sometimes also called a purebred, is an organism that always passes down certain phenotypic traits (i.e. physically expressed traits) to its offspring.
If yellow peas are dominant over green peas the offspring of a pure dominant and a pure recessive cross is?
Let Y represent the dominant allele, and yrepresent the recessive allele. Let us also assume that "pure" means homozygous for that trait ("pure' is not the usual term for this, "homozygous" is) So, the two genotypes of the parents of the cross are: Parent 1: YY Parent 2: yy To solve a problem like this, one always has to determine what kind(s) of gametes each parent can produce. Both parents are homozygous for their respective traits, so in this case, each parent can only produce one kind of gamete: Parent 1 can only produce Ygametes, and Parent 2 can only produce y gametes. Therefore, every one of their offspring will have the following genotype: Yy Since every one of the offspring of the cross carries a Y allele, and Y is dominant, all of the offspring will be yellow.
How do geneticists normally tell whether an organism exhibiting a dominant phenotype is homozygous or heterozygous?
They perform a test cross. A test cross takes the unknown genotype and crosses it with a known homozygous recessive. If the F1 generation is all dominant, then they know the organism was a homozygous recessive. If recessive offspring appear, then the organism was a heterozygote. As an example, consider a gene with two alleles, A and a, with Adominant. Now consider the test cross. The unknown genotype can only be one of two possibilities: AA (homozgous dominant) Aa (heterozygous) In a test cross,the unknown genotype is crossed with a known homozygous recessive. Since there are only two possible unknown genotypes, there can be only two possible results. First, consider the case of the unknown genotype being a homozygous dominant. The cross looks like this: AA X aa Remember that a homozygote for an allele can only produce one kind of gamete. In this case the homozygous dominant can only produce gametes with the allele A in them, while the homozygous recessive can only produce gametes with the recessive allele a in them. This means the F1 offspring can only be ONE genotype; Aa. Therefore, all of the offspring would have the dominant phenotype. Now consider the other possible cross, where the unknown genotype is heterozygous: AaX aa Remember that a heterozygote can produce two types of gametes. In this case, the unknown would produce gametes with the dominant allele A or the recessive allele a. The homozygous recessive would still only produce one kind gamete, with the recessive a allele. Therefore, we expect to see only two genotypes in the F1, Aa and aa, in equal proportions. In either case, only one test cross is needed to tell one immediately the nature of the unknown genotype. If all of the F1 are of the dominant phenotype, then the unknown genotype must be homozygous dominant; if a mixture of phenotypes appears in equal proportion, then the unknown genotype must be a heterozygote.
What kind of genes does a pure plant have?
homozygous
What happened when Gregor Mendel crossed a tall plant with a short plant?
Gregor Mendel discovered that when he crossed a tall plant with a short plant, all the resulting offspring were tall. This indicated that the trait for tallness was dominant over the trait for shortness.
What is the difference between a pure tall plant and a hybrid tall plant?
Pure TraitsPure traits can be either recessive or dominant. Pure traits may have two dominant genes or two recessive genes. For example, a pea plant may have two genes for tallness, which is dominant trait in pea plants. This plant is homozygous plant with a pure dominant trait for tallness. All of the offspring from this plant will be tall. A pea plant with two genes for shortness is also a pure organism. However, shortness in pea plants is a recessive trait. This plant is a homozygous plant with a pure recessive trait for height. The offspring from this plant will be short if it pollinates with another plant that has two genes for shortness. If this plant pollinates with a tall pea plant, the tall dominant gene will mask or cover up the recessive gene for shortness. Both plants are homozygous or pure plants; one is a pure dominant pea plant, the other is a pure recessive pea plant.Hybrid TraitOrganisms that have two unlike genes for a certain trait are called hybrid. A pea plant with one recessive gene for shortness and one dominant gene for tallness is a hybrid for that trait. A hybrid is called heterozygous, as it has two different alleles. The offspring from a pure tall pea plant, cross-pollinated with a pure short pea plant, will result in a heterozygous plant for tallness. No organism has all dominant or all recessive genes. An organism may be pure in certain traits and hybrid others. Remember, that a dominant trait in one kind of organism may be a recessive trait in another organism.
What kind of plant always produces offspring with the same trait as the parent(s)?
I think it's a true-Bred plant
To perform a testcross scientists cross an organism with an unknown genotype with what kind of organism?
To perform a testcross, scientists cross the organism with an unknown genotype with a homozygous recessive organism. This allows researchers to determine the unknown genotype based on the phenotypic ratios observed in the offspring.
What is the difference between a Pure tall plant and hybrid tall plant?
A pure tall plant refers to one that has been consistently bred with other tall plants of the same variety to maintain its tall characteristics. A hybrid tall plant, on the other hand, results from cross-breeding two different varieties of plants to create a new plant with varying characteristics, such as height.
What kind of plant will produce the same gene called?
The offspring of a plant that has all the same genes is called a clone. The same is true for animals.
What is the meaning of true breeding?
A true breeding plant is genetically homozygous. It produces the same type of plants on self fertilization. These plants are very useful for creating hybrids.
What kind of cross might tell you if a black guinea pig is BB or Bb?
A test cross with a homozygous recessive guinea pig (bb) would reveal the genotype of the black guinea pig. If all offspring are black, then the black guinea pig is most likely homozygous dominant (BB). If both black and white offspring are produced, then the black guinea pig is likely heterozygous (Bb).
What is true breeding?
Purebred organisms are the organisms in the off springs for many generations which have the same traitA true-breeding organism, sometimes also called a purebred, is an organism that always passes down certain phenotypic traits (i.e. physically expressed traits) to its offspring.
Occurs when a plant pollinates a different kind of plant?
Cross-pollination is the process by which a plant transfers pollen from one plant to a flower on a separate plant of the same species. This can lead to genetic diversity and offspring with different traits.
If yellow peas are dominant over green peas the offspring of a pure dominant and a pure recessive cross is?
Let Y represent the dominant allele, and yrepresent the recessive allele. Let us also assume that "pure" means homozygous for that trait ("pure' is not the usual term for this, "homozygous" is) So, the two genotypes of the parents of the cross are: Parent 1: YY Parent 2: yy To solve a problem like this, one always has to determine what kind(s) of gametes each parent can produce. Both parents are homozygous for their respective traits, so in this case, each parent can only produce one kind of gamete: Parent 1 can only produce Ygametes, and Parent 2 can only produce y gametes. Therefore, every one of their offspring will have the following genotype: Yy Since every one of the offspring of the cross carries a Y allele, and Y is dominant, all of the offspring will be yellow.
