The American curl is a breed of cat that has curly ears. The allele for curly ears is dominant. Suppose a male cat with the heterozygous genotype is bred to a female cat with the homozygous recessive genotype. Predict the number of kittens that will have the phenotype for curly ears. In your answer:
define the word phenotype
write the genotypes for both parents; draw a punnett square that shows a cross between the two cats (1)
write the phenotypic ration of the offspring. If the cross produces six kittens, predict how many of them will have the curly ear phototype.
Phenotype refers to the observable physical or biochemical traits of an organism, which are determined by its genotype.
In this cross, the male cat has the heterozygous genotype for curly ears, denoted as Cc. The female cat has the homozygous recessive genotype, which means she does not have the allele for curly ears, denoted as cc.
The Punnett square for this cross is as follows:
C c
c Cc cc
The possible genotypes of the offspring are Cc and cc.
The phenotypic ratio of the offspring can be determined by analyzing the genotypes. Since the allele for curly ears is dominant, the presence of at least one "C" allele will result in the phenotype for curly ears. Among the possible genotypes, only Cc will have the phenotype for curly ears.
Therefore, all kittens with the genotype Cc will have the phenotype for curly ears, while kittens with the genotype cc will have the phenotype for straight ears.
If the cross produces six kittens, we can predict that half of them will have the curly ear phenotype.
Phenotype refers to the observable characteristics or traits of an organism that are a result of the combination of genes (genotype) and their interaction with the environment.
In this scenario, the phenotype of interest is the presence of curly ears in the kittens.
The male cat has a heterozygous genotype, which means it carries one dominant allele (C) for curly ears and one recessive allele (c) for straight ears. The female cat has a homozygous recessive genotype (cc), which means it carries two recessive alleles for straight ears.
To determine the possible genotypes and phenotypes of the offspring, we can use a Punnett square.
Punnett square:
| C | c
----------------------------------
C | CC | Cc
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c | Cc | cc
From the Punnett square, we can see that there are four possible genotypes for the kittens: CC, Cc, Cc, and cc.
The CC genotype would result in kittens with curly ears, while the cc genotype would result in kittens with straight ears. The Cc genotype carriers one dominant allele for curly ears and one recessive allele for straight ears. In this case, the dominant allele for curly ears will determine the phenotype.
To determine the phenotypic ratio, we count the number of genotypes that would result in curly ears (CC and Cc) and divide it by the total number of possible genotypes. In this case, the phenotypic ratio would be 3:4 (3 curly ear genotypes out of 4 possible genotypes).
If the cross produces six kittens, we can predict that approximately 4.5 kittens (3/7 * 6) would have the phenotype for curly ears. Since we can't have half a kitten, we would round down to 4 kittens.