In the garden pea, several different genes affect pod characteristics.A gene affecting pod color (green is dominant to yellow) is approximately7 mu away from a gene affecting pod width (wide is dominantto narrow). Both genes are located on chromosome 5. A thirdgene, located on chromosome 4, affects pod length (long is dominantto short). A true-breeding wild-type plant (green, wide, longpods) was crossed to a plant with yellow, narrow, short pods. TheF1 offspring were then testcrossed to plants with yellow, narrow,short pods. If the testcross produced 800 offspring, what are theexpected numbers of the eight possible phenotypic combinations?

In Drosophila, a heterozygous female for the X-linkedrecessive traits a, b, and c was crossed to a male that phenotypically expressed a, b, and c. The offspring occurred inthe following phenotypic ratios.+  b  c                            460a  +  +                           450a  b  c                              32+ + +                              38a  + c                              11+ b +                               9 No other phenotypes were observed.(a) What is the genotypic arrangement of the alleles ofthese genes on the X chromosome of the female?

Two recessive traits in mice—droopy ears and flaky tail—arecaused by genes that are located 6 mu apart on the same chromosome.A true-breeding mouse with normal ears (De) and a flaky tail ( ft)was crossed to a true-breeding mouse with droopy ears (de) and anormal tail (Ft). The F1 offspring were then crossed to mice withdroopy ears and flaky tails. If this testcross produced 100 offspring,what is the expected outcome of phenotypes?

You are doing a cross with Drosophila using the following two traits. Curly wings is dominant over straight wings, and round eyes is dominant over elliptical eyes. You cross a female fly that is known to be heterozygous for both genes with a male that is heterozygous for the wing gene but has elliptical eyes. This cross produces 74 flies with curly wings and round eyes, 61 with curly wings and elliptical eyes, 24 with straight wings and round eyes, and 21 with straight wing and elliptical eyes. Calculate the expected phenotype ratios for this cross, then use the chi-square test to see if the observed data are consistent with the expected numbers.

Two pure-breeding lines of petunia plants are crossed. Line 1 plants grow to a height of 54 cm, and Line 2 plants grow to a height of 18 cm. Petunia plant height is controlled by three genes, A, B and C. Line 1 has the genotype A₁A₁B₁B₁C₁C₁, and line 2 has the genotype A2A2B₂B₂C₂C₂. Assume that genotype alone determines plant height under ideal growth conditions and that the alleles of the three genes are additive. If the F1 plants are self crossed, what is the expected proportion of F2 plants with the genotype A₁A₁B₁B₁C₁C₁ 1/8 1/32 1/16 1/4 1/64

In the mapping example in Fig 2, the dominant alleles were on one chromosome and the recessive alleles were on the homolog. Let’s consider a twofactor cross in which the dominant allele for one gene is on onechromosome, but the dominant allele for a second gene is on thehomolog. A cross is made between AAbb and aaBB parents. The F1offspring are AaBb. The F1 heterozygotes are then testcrossed to aabbindividuals. What topic in genetics does this question address?

In Drosophila melanogaster, vestigial (short) wings (vg) are caused by a recessive mutant gene that independently assorts with a gene pair that influences body hair.  Hairy (h ) results in a  hairy  body.   A cross is made between a fly with normal wings and a hairy body and a fly with vestigial wings and a normal body.  The phenotypically normal F1 flies were crossed among each other and 1024 F2 flies were reared.  What phenotypes would you expect in the F2 and in what actual numbers (not ratio) would you expect to find them?

In a variety of tomato plant ,the leaves maybe pure green,pure white,or variegated (mixture). a)when 2 variegated plants were crossed,87 offspring were produced,of these 20 were green,46 were variegated and 21 remain died soon after germination.Draw a genetic diagram to explain these results,why did 21 of them died

O All three genes are linked, but need to do more crosses and data to determine the gene order. All three genes are linked with the flower color gene (F) in the middle. All three genes are linked with the seed weight gene (S) in the middle. All three genes are linked with the leaf size gene (L) in the middle.

In Drosophila, Dichaete (D) is a mutation on chromosome III witha dominant effect on wing shape. It is lethal when homozygous.The genes ebony body (e) and pink eye (p) are recessive mutations on chromosome III. Flies from a Dichaete stock were crossed to homozygous ebony, pink flies, and the F1 progeny with a Dichaete phenotype were backcrossed to the ebony, pink homozygotes. Question: a.) Using the results of this backcross shown in the following table, diagram the cross, showing the genotypes of the parents and offspring of both crosses. b.) What is the sequence and interlocus distance between thesethree genes? Phenotype                   NumberDichaete                       401ebony, pink                  389Dichaete, ebony            84pink                               96Dichaete, pink                 2ebony                              3Dichaete, ebony, pink    12wild type                        13