Question

In: Biology

In violets, purple is dominant to white and tall stems are dominant to short stems. ....

In violets, purple is dominant to white and tall stems are dominant to short stems. . A tall purple plant that is heterozygous at both loci is crossed with a double homozygous recessive plant. What is the probability of obtaining either a tall white plant or a short purple plant? What percent of the offspring are expected to be heterozygous at one or both loci? What will be the expected ratio of the F2 offspring of the F1 generation?

Expert Solution

Let's first stablish the allele letters: P for Purple and p for white, T for Tall and t for short.

And now let's write down the genotypes for the parents:

Parent 1: PpTt

Parent 2: pptt

- What is the probability of obtaining either a tall white plant or a short purple plant?

Let's make the punnet square:

	PT	Pt	pT	pt
pt	PpTt (purple, tall)	Pptt (purple, short)	ppTt (white, tall)	pptt (white, short)

The probability for a white-tall is 1/4, and for a purple-short is 1/4 too, so the probability for either of them is the sum of those probabilities:

1/4 + 1/4 = 1/2 = 50%

- What percent of the offspring are expected to be heterozygous at one or both loci?

There are 3 out of 4 that have one or both heterozygous loci: PpTt, Pptt and ppTt. That is 3/4 which is 75%

- What will be the expected ratio of the F2 offspring of the F1 generation?

Not sure what this question talks about, maybe to obtain an F2 from the F1 we already created, but it doesn't specifies which F1 genotypes we are going to cross. Let us cross the double heterozygous. The punnet square is:

	PT	Pt	pT	pt
PT	PPTT	PPTt	PpTT	PpTt
Pt	PPTt	PPtt	PpTt	Pptt
pT	PpTT	PpTt	ppTT	ppTt
pt	PpTt	Pptt	ppTt	pptt

This leads to the following ratios:

Purple-tall: 9/16

Purple-short: 3/16

White-tall: 3/16

White-short: 1/16

gladiator answered 2 years ago

1. Tall (T), Purple (P), and Round (R) are dominant to Short (t), White (p), and...

1. Tall (T), Purple (P), and Round (R) are dominant to Short (t), White (p), and Wrinkled (r). The following pea plants were crossed (TtPpRr X ttpprr) and produced the offspring below: Phenotypes of offspring Number of offspring Tall White Wrinkled 7 Short White Wrinkled 48 Tall White Round 98 Tall Purple Wrinkled 29 Tall Purple Round 42 Short Purple Wrinkled 102 Short Purple Round 13 Short White Round 31 a. Determine the arrangement of alleles on the homologous chromosomes...

16. In peas, tall plants (T) are dominant to short (t) and purple (P) is dominant...

16. In peas, tall plants (T) are dominant to short (t) and purple (P) is dominant to white flower color (p). What are the phenotypes of cross between ttPp and TtPP?

In pea plants, purple flower color is dominant over white. If one sees a purple pea...

In pea plants, purple flower color is dominant over white. If one sees a purple pea plant and has no prior knowledge of its ancestry, what can be said its genotype? A. It is pp B. It is Pp C. It is PP D. It is either PP or Pp

Let P = purple flowers and p = white, and T = tall plants and t...

Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What are the genotypes of the gametes that are produced by a plant that is heterozygous for both traits? a. PpTt only b.PT and pt c. P, p, T, and t d. PT, Pt, pT, and pt e. Tt, TT, tt, Pp, PP, and pp

In cactus, long spines are dominant to short and pink flowers are dominant to white. A...

In cactus, long spines are dominant to short and pink flowers are dominant to white. A true-breeding short-spined cactus that is a carrier for flower color is crossed with a cactus that is heterozygous for both traits. This cross produces 200 seeds. How many of these seeds would you expect to germinate as short-spined, pink-flowered cacti?\ 25 75 100 150

In garden peas, tall plants are dominant to short plants and smooth seeds are dominant over...

In garden peas, tall plants are dominant to short plants and smooth seeds are dominant over wrinkled seeds. If two heterozygous tall plants with smooth seeds (TtRr) are crossed, what are the potential genotypes and phenotypes that can be expected in the offspring? What is the genotype of the parents? What are the gametes for each parent? What is the phenotypic ratio? What proportion of the Tall plants with smooth seeds is heterozygous for both traits?

In peas, tall (T) is dominant to short (t), yellow (Y) is dominant to green (y)...

In peas, tall (T) is dominant to short (t), yellow (Y) is dominant to green (y) and round (R) is dominant to wrinkled (r). A purebreeding plant with tall, green and wrinkled pea phenotypes is crossed to a purebreeding plant that is short and makes yellow, round peas. When peas from this F1 generation are crossed, what is the probability of obtaining a short plant that makes yellow, wrinkled peas in the F2?

Tall is dominant over short, green seeds is dominant over yellow seeds. Give the result (...

Tall is dominant over short, green seeds is dominant over yellow seeds. Give the result ( GENOTYPES AND PHENOTYPES) from the cross below. p- Homozygous Tall /Green x Homozygous Short/Yellow F1- ? F2- ? **Any monohybrid cross results in A 3:1 Ratio **Any dihybrid cross results in A 9:3:3:1 Ratio

12. If a heterozygous dominant tall pea is crossed with a short plant, what is the...

12. If a heterozygous dominant tall pea is crossed with a short plant, what is the expected phenotype ratio? 13. Give three examples of phenotypes. 14. Why is skin color classified as polygenic inheritance? 15. If the parental genotype is EeWw, what are the potential allele combinations that could occur at the end of meiosis? 16. During DNA replication, a DNA strand with the bases CTAGGT will produce what complimentary strand of bases? 17. In their experiment, what would Hershey...

In pea plants, tall (T) is dominant over short (t). What are the genotypes and phenotypes...

In pea plants, tall (T) is dominant over short (t). What are the genotypes and phenotypes of the offspring of a cross between a TT and a tt plant? Genotype____________ Phenotype___________