Question

Which of the following correctly describes this cross? Choose all that apply. Now determine the genotypes...

Which of the following correctly describes this cross? Choose all that apply.

Now determine the genotypes of the possible gametes and set up a Punnett square for the cross between two double heterozygotes, as you did before in a previous question (no need to attach that Punnett square). From your Punnett square, determine how many individual kernels have the genotypes and phenotypes shown in the table below. Enter your answers as a number (e.g. 7) not a word (e.g. seven)

X

Y

Z

W

In Mendel’s pea plants, the dominant flower color was purple, which we can indicate as P. The recessive color, white, can therefore be expressed as p. If you were given a random pea plant with purple flowers, how would you be able to tell if the plant was homozygous (PP) or heterozygous (Pp)? The answer lies in the fact that even though purple flowers can be PP or Pp, white flowers can only be pp. So the genotype of an individual expressing the recessive allele is always known. Determine the outcome of two crosses to a white flower: in one case hypothesize that the purple parent is homozygous, and in the other hypothesize that it is heterozygous.

Hypothesis 1: The purple parent is homozygous, PP. What would be the offspring's genotype and phenotype after a test cross between this parent and a homozygous recessive pp organism?

In Mendel’s pea plants, the dominant flower color was purple, which we can indicate as P. The recessive color, white, can therefore be expressed as p. If you were given a random pea plant with purple flowers, how would you be able to tell if the plant was homozygous (PP) or heterozygous (Pp)? The answer lies in the fact that even though purple flowers can be PP or Pp, white flowers can only be pp. So the genotype of an individual expressing the recessive allele is always known. On the Punnett squares below determine the outcome of two crosses to a white flower: in one case hypothesize that the purple parent is homozygous, and in the other hypothesize that it is heterozygous. Write the genotypes of the white parent along the top of the square and that of the purple parent along the side.

Hypothesis 2: The purple parent is heterozygous, Pp. If the test cross is between this parent and the homozygous recessive pp individual, what would be the genotype and phenotype of their offspring?

Homework Answers

Answer #1

Answer:

If testcross ratio is 1:1 (purple : white), it means that the hybrid genotype would be Pp (heterozygous). See punnet square.

Pp (hybrid) x pp (white)---Testcross

p

P

Pp (purple)

p

pp (white)

Phenotypic ratio = Purple (1) : White (1)

If testcross ratio produces only purple phenotype progeny, it means that the hybrid genotype would be PP (homozygous). See punnet square.

PP (hybrid) x pp (white)---Testcross

p

P

Pp (purple)

Phenotypic ratio= All progeny are purple.

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
In pea plants, the allele for purple flowers ( W ) is dominant to the allele...
In pea plants, the allele for purple flowers ( W ) is dominant to the allele for white flowers ( w ). To determine whether a plant with purple flowers is homozygous or heterozygous with respect to flower color, the plant should be crossed with another pea plant with what genotype and phenotype with respect to flower color?
Part A)i n plants, purple flower color is dominant to white flowers color. You crossed a...
Part A)i n plants, purple flower color is dominant to white flowers color. You crossed a white flowering plant with a purple flowering plant. Out of 236 plants in the offspring, 114 had white flowers and the other 122 had purple flowers. What were the genotypes of the parent plants? A. One plant was heterozygous white and the other heterozygous purple B. Both plants are homozygous C.Both plants are heterozygous D. One plant was homozygous white and the other heterozygous...
In a Mendelian cross, a red flowering heterozygous male plant is crossed with a white flowering...
In a Mendelian cross, a red flowering heterozygous male plant is crossed with a white flowering homozygous female plant. Most of the children of this cross (generation F1) produce red flower. 1) In this crossing by the progeny produced we can conclude that the recessive allele is: a-produce white flower b-produce red flower c-produce pink flower d-the recessive allele cannot be determined 2) phenotype of the female parent plant is: a-produce red flower b-homozygous dominant c-homozygous recessive d-produce white flower...
You then cross a plant that is heterozygous for flower color and seed shape and is...
You then cross a plant that is heterozygous for flower color and seed shape and is homozygous recessive for seed color with a plant that is heterozygous for flower color and seed color but is homozygous dominant for seed shape. a) What is the probability that the off spring from this cross will be homozygous recessive for all of the loci? b) What is the probability that the offspring will have purple flowers? c) What is the probability that the...
1) One parent has yellow flowers, which is the dominant allele Y. The second parent has...
1) One parent has yellow flowers, which is the dominant allele Y. The second parent has white flowers, the recessive allele y. If the offspring are all yellow, what is the genotype of each parent? 2) A plant is homozygous for the recessive gene "a" causing the plant to be short. What is the genotype and the phenotype of this plant? (In your answer, be very clear about which is the genotype and which is the phenotype). 3) The allele...
Purple flowers (P) are completely dominant over white flowers (p) in pea plants. A plant that...
Purple flowers (P) are completely dominant over white flowers (p) in pea plants. A plant that is heterozygous for purple flowers (male) is crossed with another plant that has white flowers (female). Use a Punnett square to determine the expected genotypic and phenotypic ratios for the offspring. What is the purple pea plant's genotype? What is the white pea plant's genotype? What are the purple pea plant's gametes? What are the white pea plant's gametes? What is the expected genotypic...
You are studying inheritance of various characters in marigolds including flower color (purple or blue), seed...
You are studying inheritance of various characters in marigolds including flower color (purple or blue), seed color (white or brown) and seed shape (round or oblong). When you cross a plant that is true breeding for blue flowers, white and oblong seeds with a plant that is true breeding for purple flowers, brown and round seeds you find that all of the offspring have blue flowers, and round, white seeds. You then cross these F1 plants with each other and...
p+q =1 All of the allele frequencies p2 + 2pq + q2 =1 All of the...
p+q =1 All of the allele frequencies p2 + 2pq + q2 =1 All of the genotype frequencies together equals 1 p2 and q2 Frequencies for each homozygotes 2pq Frequencies for Heterozygotes. p2 + 2pq= + q2 Homozygous Dominant Heterozygous Homozygous recessive If the frequencies of the color in Homozygous recessive frequencies pea plants are 30% in the population what are the genotype and phenotype frequencies in the populations. A homozygous recessive plant would be (pp) and a Homozygous dominant...
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...
Tallness (T ) in snapdragons is dominant to dwarfism (t ), while red (R ) flower...
Tallness (T ) in snapdragons is dominant to dwarfism (t ), while red (R ) flower color is incompletely dominant to white (R' ). The heterozygous condition results in pink (RR' ) flower color. The genes for these traits occur on separate chromosomes. A dwarf, red snapdragon is crossed with a plant homozygous for tallness and white fowers. a) Determine the genotypes of the parents. b) Determine all the types of gametes each parent can produce. c) Complete the Punnett...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT