In humans, six fingers (F) is the dominant trait; five fingers (f) is the recess
ID: 83407 • Letter: I
Question
In humans, six fingers (F) is the dominant trait; five fingers (f) is the recessive trait. Both parents are heterozygous for six fingers. What is the phenotype of the father and the mother? What is the genotype of each parent? What is the probability of them having six-fingered children? Five-fingered children? a. Father's phenotype ________ Mother's phenotype _________ b. Father's genotype ______ Mother's genotype _______ c. Father's gametes _________ or ________ d. Mother's gametes _______ or ______ e. Probability of a six-fingered child _______ f. Probability of a six-fingered child ______ If the father is heterozygous for six fingers and mother has five fingers, what is the probability of having these characteristics in their offspring? Six fingers _____Five fingers _____ In certain flowers, color is inherited by alleles that show lack of dominance (incomplete). In such flowers, a cross between a homozygous red and homozygous white always results in a pink flower. A cross in made between two pink flowers. What is the probability of these colors (red. pink, and white) appearing in the offspring? Use the information given in the previous problem. A cross is made between a red flower and a pink flower. What is the expected probability for the various colors? A double-factor cross is a genetic study in which two pairs of alleles are followed from the parental generation to the offspring. These problems are basically worked the same as a single-factor cross. The main differences are that in a doublefactor cross you work with two different characteristics from each parent. It is necessary to use Mendel's law of independent assortment when working double-factor inheritance problems. This law states that members of one allelic pair separate from each other independently of the members of other pairs of alleles. This happens during meiosis when the chromosomes segregate. (Mendel's law of independent assortment only applies if the two pairs of alleles are located on separate chromosomes. This is an assumption we will use in double-factor crosses.) In humans, the allele for free earlobes dominates the allele for attached earlobes.Explanation / Answer
Ans 3.If we represent gene for red color by R and gene for white color by W, the detail of experimental results can be displayed as under-
Homozygous red colour of plants have both genes of R type. There genotype is RR. All gamete which they produce will contain gene R.
Homozygous white colour of plants have both genes of W type. There genotype is WW. All gamete which they produce will contain gene W.
Plants formed through their crossed will contain one R gene and one W gene. There genotype is RW. All plants will produce pink color flowers.
Plants produced from self crossed of pink flower plants yields 1 red flower:2pink flower:1 white flower ratio.
( If the cross is made between two pink flowers then there will be probability of 25% red ,25%white and 50% pink flower.)
R W
RR
RW
RW
W
R
W
Ans 4. If the cross is made between red flowered plant and pink flower plant, then there will be probability of 50 % red flower and 50% pink flower.
R R
RR
RR
RW
RW
R
W
RR
RW
RW
W