Question

A variety of pure-breeding snapdragons produces a tall plant with green seeds (WWSS). A second variety...

A variety of pure-breeding snapdragons produces a tall plant with green seeds (WWSS). A second variety of pure-breeding snapdragons produce a short plant with white seeds (wwss). The two varieties are crossed, and the resulting seeds are collected. All of the seeds are green and when planted, they produce all tall plants (WwSs). These tall F1 plants are allowed to self-fertilize. The results for seeds and plant height in the F2 generations are as follows. What is the ?2 value, and the degrees of freedom for this experiment?

F2 Plant phenotype

Observed #

Green seed, tall

600

White seed, tall

175

Green seed, short

165

White seed, short

60

Total

1000

?2 = 6.1, df = 4

?2 = 6.1, df = 1

?2 = 0.4, df = 3

?2 = 0.4, df = 4










?2 = 6.1, df = 3

?2 = 0.4, df = 1

Homework Answers

Answer #1

Answer:    ?2 = 6.1, df = 3

Explanation:

During F2 generation of Dihybrid cross, progeny are produced in the following manner.

Both dominant phenotypes = 9/16 –green seed, tall

First dominant phenotype and second is recessive phenotype = 3/16—green seed, short

First recessive phenotype and second is dominant phenotype = 3/16---white seed, tall

Both recessive phenotypes = 1/16---white seed, short

Phenotype Observed(O) Expected (E) O-E (O-E)2 (O-E)2/E
green seed, tall 600 562.50 37.50 1406.25 2.50
green seed, short 165 187.50 -22.50 506.25 2.70
white seed, tall 175 187.50 -12.50 156.25 0.83
white seed, short 60 62.50 -2.50 6.25 0.10
Total 1000 1000.00 6.13

X2 value = 6.1

Degrees of freedom = number of phenotype class -1 = 4-1 = 3

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Mendel crossed a pure breeding tall pea plant having red flowers with a pure breeding short...
Mendel crossed a pure breeding tall pea plant having red flowers with a pure breeding short pea plant having white flowers. All the F1 plants were tall with red flowers. He then selfed the F1 plants and the F2 plants had new combination of traits. Using a punnet square, show the phenotypes and genotypes of the F2 plants.
A true breeding tall purple pea plant is crossed with a true breeding short white pea...
A true breeding tall purple pea plant is crossed with a true breeding short white pea plant. Purple and tall are dominant. What is the genotype and phenotype of the F1 offspring. If two of the F1 offspring are crossed, what will be the phenotypes and genotypes of the F2 offspring? A tall purple pea plant is crossed with a short white pea plant. What will the phenotype(s) and genotype(s) of the F1 offspring be?
. A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that...
. A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that is pure-breeding for green, round seeds. (Remember that yellow and round are the dominant alleles). a. Use a Punnett square to predict the F2 progeny that would be expected if the F1 are allowed to self-fertilize. b. What proportion of the F2 progeny are expected to have yellow seeds? Wrinkled seeds? Green seeds? Round seeds? c. What is the expected phenotype distribution (ratio) among...
The seeds from Mendel’s tall plants were round and yellow, all three characters due to a...
The seeds from Mendel’s tall plants were round and yellow, all three characters due to a dominant gene at each of three independently assorting loci. The recessive genotypes dd, ww, and gg produce dwarf plants with wrinkled and green seeds, respectively., (a) If a pure, tall wrinkled and yellow variety is crossed with a pure dwarf, round, green variety, what phenotypic ratio is expected in the F1 and F2? (b) What percentage of the F2 is expected to be of...
In snapdragons, the plant height gene and the flower color genes are located on different chromosomes....
In snapdragons, the plant height gene and the flower color genes are located on different chromosomes. Tall (T) is dominant to dwarf (t). Red flowers (FR) are incompletely dominant to white (FW), with the hybrid being pink. A homozygous tall-white is crossed to a homozygous dwarf-red,. The F1 plants are then self-fertilized to produce an F2 generation. a. What is the genotype and phenotype of the F1? b. What proportion of the F2 will have pink flowers? c. What proportion...
In a whatzit plant, green stems (G) are dominant over gray (g)and hairy seeds (H) are...
In a whatzit plant, green stems (G) are dominant over gray (g)and hairy seeds (H) are dominant over smooth (h) seeds. You cross true-breeding parental plants to produce an Figeneration (hybrid). Next, you crossed two hybrid plants from the F 1 generation to produce an F 2 Identify the genotypes for the P generation the genotype and phenotype ratios for the F 1 generation and design a Punnett Square to determine what genotype and phenotype ratios will be present in...
a) In radishes, the plants can be tall (allele T) or dwarf (allele t). Tall is...
a) In radishes, the plants can be tall (allele T) or dwarf (allele t). Tall is dominant. Root color can be red (allele RR), white (allele RW), or pink (heterozygote). A radish that is true-breeding for both red roots and tallness (RRRR TT) is crossed with a radish that is true-breeding for both white roots and being dwarf (RWRW tt). Write the genotype and phenotype for the F1 generation. b) Assume the two genes for plant height and root color...
Answer all 3 parts of the question. a) In radishes, the plants can be tall (allele...
Answer all 3 parts of the question. a) In radishes, the plants can be tall (allele T) or dwarf (allele t). Tall is dominant. Root color can be red (allele RR), white (allele RW), or pink (heterozygote). A radish that is true-breeding for both red roots and tallness (RRRR TT) is crossed with a radish that is true-breeding for both white roots and being dwarf (RWRW tt). Write the genotype and phenotype for the F1 generation. b) Assume the two...
1. Cross a homozygous purple Plant (PP) with a homozygous white plans (PP). This is called...
1. Cross a homozygous purple Plant (PP) with a homozygous white plans (PP). This is called the P1 cross, and it will produce offspring called the F1 generation. You are given that purple color is dominant to white in this species. a) What is the genotype of the purple plant? b) What gametes can the purple plant make? c) What is the genotype of the white plant? d) What gametes can the white plant make? e) Create a Punnett Square...
1. In humans, there are several mutations that can cause hereditary deafness. Most of these mutations...
1. In humans, there are several mutations that can cause hereditary deafness. Most of these mutations are recessive, yet two deaf people can marry and produce children with normal hearing. This is explained by the fact that deafness shows _________. The "Threshold Effect" Conditional mutations Genetic heterogeneity Genetic anticipation 2. An individual with classic symptoms of Down syndrome is found to have 46 chromosomes. How can this be? It is possible if she or he carries a chromosome translocation, such...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT