Biology Reports
1. Given the following parental genotypes, show all possible gametes that each could form. Circle each gamete. Note: different gamete types are separated by commas in the table below.
Genotype Gametes: AA A Aa A, a Bb B, b bb b cc c AABB AB AAbb Ab Aabb Ab, ab AaBb AB, Ab, aB, ab AaBbCc ABC, ABc, Abc, AbC, aBc, aBC, abC, abc 2. In summer squash, white fruit color (W) is dominant over yellow (w). If a squash plant homozygous for white is crossed with one homozygous for yellow, what will be the apearance of the F1? of the F2? of the offspring of a cross of the F1 back to its white parent? of the offspring of a cross of the F1 back to its yellow parent? Parents: WW (white) x ww (yellow) F1: all white (Ww) F2: 3/4 white (1/4 WW + 1/2 Ww) : 1/4 yellow (ww) F1 white (Ww) x white parent (WW) offspring: all white (1/2 WW + 1/2 Ww) F1 white (Ww) x yellow parent (ww) offspring: 1/2 white (Ww) : 1/2 yellow (ww) 3. A white-fruited squash plant when crossed with a yellow-fruited one produces offspring about half of which are white and half yellow. What are the genotypes of the parents? Note that the yellow parent must be homozygous ww.
The white parent may be either WW or Ww.
Note that 1/2 of the offspring from this cross are yellow (ww), therefore the white parent must be heterozygous (Ww).
4. Two white-fruited squash plants, when crossed with each other, produce about three-fourths white and one-fourth yellow offspring. What are the genotypes of these two parents? What will each produce if crossed with a yellow-fruited plant? Note that a phenotypic ratio of 3/4 to 1/4 is what you expect from a monohybrid cross between two heterozygous parents (Ww x Ww).
Note that the second cross (to a yellow-fruited plant) is a testcross (a cross beetween an individual with the dominant phenotype and a homozygous recessive parent). The progeny expected from such a cross (Ww x ww) are: 1/2 white (Ww) : 1/2 yellow (ww) 9. In cattle the polled (hornless) condition (P) is dominant over the
Genotype Gametes: AA A Aa A, a Bb B, b bb b cc c AABB AB AAbb Ab Aabb Ab, ab AaBb AB, Ab, aB, ab AaBbCc ABC, ABc, Abc, AbC, aBc, aBC, abC, abc 2. In summer squash, white fruit color (W) is dominant over yellow (w). If a squash plant homozygous for white is crossed with one homozygous for yellow, what will be the apearance of the F1? of the F2? of the offspring of a cross of the F1 back to its white parent? of the offspring of a cross of the F1 back to its yellow parent? Parents: WW (white) x ww (yellow) F1: all white (Ww) F2: 3/4 white (1/4 WW + 1/2 Ww) : 1/4 yellow (ww) F1 white (Ww) x white parent (WW) offspring: all white (1/2 WW + 1/2 Ww) F1 white (Ww) x yellow parent (ww) offspring: 1/2 white (Ww) : 1/2 yellow (ww) 3. A white-fruited squash plant when crossed with a yellow-fruited one produces offspring about half of which are white and half yellow. What are the genotypes of the parents? Note that the yellow parent must be homozygous ww.
The white parent may be either WW or Ww.
Note that 1/2 of the offspring from this cross are yellow (ww), therefore the white parent must be heterozygous (Ww).
4. Two white-fruited squash plants, when crossed with each other, produce about three-fourths white and one-fourth yellow offspring. What are the genotypes of these two parents? What will each produce if crossed with a yellow-fruited plant? Note that a phenotypic ratio of 3/4 to 1/4 is what you expect from a monohybrid cross between two heterozygous parents (Ww x Ww).
Note that the second cross (to a yellow-fruited plant) is a testcross (a cross beetween an individual with the dominant phenotype and a homozygous recessive parent). The progeny expected from such a cross (Ww x ww) are: 1/2 white (Ww) : 1/2 yellow (ww) 9. In cattle the polled (hornless) condition (P) is dominant over the