Answer: option A, an organism only needs one dominant allele to show the dominant trait. Explanation: A test cross between two individuals helps to determine the genotype of off springs and thus decide their phenotypic characteristics.
Is it necessary to do a test cross to determine the genotypes of the offspring?
Test crosses operate under the same principle no matter whether you are considering one gene or multiple genes; in all cases, you are crossing an individual of a dominant phenotype but unknown genotype to an individual that is homozygous recessive for all relevant genes.
How does test Cross help to determine the genotype of an individual?
Detailed Answer :Test-cross helps to determine the unknown genotype by crossing it with the recessive parent. If in the progeny all are dominant type then the individual is homozygous and if in the Progeny dominant to recessive ratio is 1 : 1 the individual is heterozygous.
How can you tell if a genotype is purebred?
Originally Answered: What are some examples of purebred genotypes?? Purebred means that both alleles of a gene in a particular individual are the same. If the allele codes for a recessive feature, and the phenotype displays the recessive feature, then you know that the particular individual is purebred for that allele.
Why is test cross done?
A test cross is performed in order to determine the genotype of a dominant parent, i.e., whether it is a heterozygous or a homozygous dominant. On the basis of the results obtained, the ratios of the offsprings help us to predict that the parent has which type of genotype.
Can you determine a person’s genotype based on the phenotype?
The sum of an organism’s observable characteristics is their phenotype. A key difference between phenotype and genotype is that, whilst genotype is inherited from an organism’s parents, the phenotype is not. Whilst a phenotype is influenced the genotype, genotype does not equal phenotype.
What is the genotype for gray fur?
ff: 257. Black fur: 257. Grey fur: 757. Genotypes: EE: 1007.
What is meant by genotype?
In a broad sense, the term “genotype” refers to the genetic makeup of an organism; in other words, it describes an organism’s complete set of genes. Each pair of alleles represents the genotype of a specific gene. … For example, in sweet pea plants, the gene for flower color has two alleles.