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Describe how to use the phenotype ratios to determine the percentage of offspring displaying each trait..a heterozygous gray bug Gg is crossed with a homozygous black bug gg?
Wiki User
∙ 12y ago
i dont nkonw - - - -
Ignore that person.
If you are using a Punnett Square (2X2 box) then you will see that if you have a Gg (across the top) and gg (down the side) you will have Gg, Gg, gg, gg. The lowercase letters represent recessive traits and the uppercase dominant. The ratios are split into Phenotypes and Genotypes. If you have at least one dominant trait then it is considered a genotype (for this problem Gg GG). Double recessive is a phenotype (double lower case-in this case gg.) Your ratio for the above Gg, Gg, gg, gg is 2:4 (1:2) for both Phenotype and Genotype.
Hope this helps!
Wiki User
∙ 12y ago
Wiki User
∙ 9y agoYou can use the genotype ratios to determine the percentage of offspring using a punnet square. The punnet square shows you the ratios of a certain trait.
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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
To determine the genotype of an individual that shows the dominant phenotype you would cross that individual with one that is?
To determine the genotype of an individual that shows the dominant phenotype you would cross that individual with one that is homozygous recessive. A monohybrid cross of two individuals that are heterozygous for a trait exhibiting complete dominance would probably result in a phenotype ratio is 3 dominant 1 recessive.
How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous?
A cross between a plant of unknown genotype and one that is known to be homozygous recessive is called a test cross because the recessive homozygote testswhether there are any recessive alleles in the unknown. Because the recessive homozygote will contribute an allele for the recessive characteristic to each offspring, the second allele (from the unknown genotype) will determine the offspring's phenotype.
When would a pedigree be better to use to deterimine the genotype of an individual instead of a testcross?
n genetics, a test cross, first introduced by Gregor Mendel, is used to determine if an individual exhibiting a dominant trait is homozygous or heterozygous for that trait. More simply put, test crosses determine the genotype of an individual with a dominant phenotype.
How do you determine how many offspring will be the dominant color?
You can use a Punnet Square to figure it out. For example, if gray elephants dominate over brown elephants, and you cross 1 homozygous gray elephant (GG) and one homozygous brown elephant (gg), the Punnet square predicts that the offspring will all be heterozygous Gg. They will all be gray, however, because gray dominates over brown.
What cross should a scientist perform in order to determine if the organism is heterozygous or homozygous dominant?
Scientists use a test cross to determine if an organism is heterozygous or homozygous dominant.
To determine if a particular plant is homozygous or heterozygous you would have to test cross with a?
Homozygous recessive plant
To determine if a particular plant is homozygous or heterozygous you would have to test cross with a what?
poop
What is the difference between a herezygous and a homozygous?
"Heterozygous" and "homozygous" are terms that refer to alleles, which, in genetics determine what trait, from which parent, will appear in the offspring. Alleles can be either Dominant or Recessive. Every organism has two alleles, which can both be dominant, both recessive, or one of each.So,If an organism heterozygous, it has one recessive and one dominant allele.If an organism is homozygous then both of its alleles are the same; you need to specify if they are homozygous recessive (both alleles are recessive) or homozygous dominant (both alleles are dominant).
Is it easier to analyze genotype by observing phenotype in organisms with complete dominance or in organisms with incomplete dominance?
It is easier to analyze genotype by observing phenotype in organisms with incomplete dominance (also known as codominance), because in incomplete dominance the individual will show a specific phenotype for each situation, whether it is homozygous dominant, heterozygous, or homozygous recessive. For example, in flowers, such as the ones that Mendel studied, a homozygous dominant flower will be red, a homozygous recessive flower will be white, and a heterozygous flower will be pink. In complete dominance, a heterozygous will only express the dominant phenotype, as opposed to incomplete dominance, in which a heterozygous individual will express a phenotype that is representative of both of the dominant and recessive traits. Because heterozygous individuals in complete dominance express the dominant phenotype, it is hard to determine whether the genotype is homozygous dominant or heterozygous for the trait. Hope this helps!
Why is an organism genotype may be homozygous dominant homozygous recessive or heterozygous but never heterozygous recessive?
I take it you're referring to the phenotype. Say a trait, like flower colour, is influenced by a single gene. The plant will possess two copies of the gene, one from each parent, but only one colour is expressed. Let's say that red is dominant and white is recessive. A plant containing 2 red alleles (homozygous for the dominant allele) will be red. A plant containing 2 copies of the white allele (Homozygous recessive) will be white and heterozygous plant, containing a single copy of both alleles will be red. There is no heterozygous recessive because the dominant allele will determine the phenotype.
In sheep the allele for white wall parentheses A is dominant over the allele for black wall parentheses a how do you determine the genotype of a white ram or male sheep?
To determine the genotype of a white ram, breed him with black females. Black females are homozygous recesive for the black trait, a. If the ram is homozygous dominant, all offspring will be white (and heterozygous). If the ram is heterozygous, approximately half of it's offspring will be white and half will be black.
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
Can Achondroplasia be detected before birth?
Yes, it can be detected before birth. Doctors can use an ultrasound to determine if the child is homozygous dominant or heterozygous, in which cases the child would be infected with Achondroplasia, because it is a dominant trait.
When can you accurately determine a person's genotype from their phenotype?
Yes you can accurately determine an organisms genotype by observing it's phenotype, however some phenotypic traits resulting from homozygous or heterozygous combinations of alleles, may make the prediction impossible.
To determine the genotype of an individual that shows the dominant phenotype you would cross that individual with one that is?
To determine the genotype of an individual that shows the dominant phenotype you would cross that individual with one that is homozygous recessive. A monohybrid cross of two individuals that are heterozygous for a trait exhibiting complete dominance would probably result in a phenotype ratio is 3 dominant 1 recessive.
How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous?
A cross between a plant of unknown genotype and one that is known to be homozygous recessive is called a test cross because the recessive homozygote testswhether there are any recessive alleles in the unknown. Because the recessive homozygote will contribute an allele for the recessive characteristic to each offspring, the second allele (from the unknown genotype) will determine the offspring's phenotype.
