Consider the true diploid plant cell (2n=4) below. The paternally derived blue chromosomes are of two types, metacentric and acrocentric. These chromosomes contain the same gene pattern and structural features as the maternally derived purple chromosomes. Consider two genes A and B which are found on the metacentric and acrocentric chromosome pairs, respectively. Assume the father passed on A and B alleles, and the mother passed on a and b alleles.  a. Show the possible loci of these genes (specify alleles) on the image on the left. Label both sister chromatids in each chromosome. (Note: Sister chromatids are products of replication.) b. Draw the four possible gametes formed after meiosis assuming there was no crossing over. Label the gene loci.

A diploid species has 3 pairs of chromosomes in the somatic cells. In males, the first pair is large submetacentric; the second is medium acrocentric, and the third is small telocentric. In females, the first two pairs are like those of the males while the third is large metacentric with satellite. Illustrate the karyograms of the following: a. A triploid cell in femalesb. tetrasomic cell in malesc. tetraploid cell in females

Consider the true diploid plant cell (2n=2x=6) below wherein the light blue chromosomes A, B, C (from largest to smallest) are paternally derived. These chromosomes contain the same gene pattern and structural features as maternally-derived purple chromosomes A’, B’, and C’, respectively. Draw and label the chromosomes as observed in the following stages Anaphase (c.1), Anaphase I (c.2), and Anaphase II (c.3). Assume no crossing-over events occurred at Meiosis.

A diploid (2n) trihybrid individual with the genotype AaBbDd can make eight genetically different gametes. 2n = 4 n = 2 (1) A d. ID 1 1 2 2 Gt: AaBbDd Loci A/a and D/d are on chromosome 1 and locus B/b is on chromosome 2. Explain how a gamete containing the alleles A, D and b may be produced by meiosis. Refer specifically to meiotic events occurring during Prophase I, Metaphase I, Anaphase I and Anaphase II. (NB: remember to refer to the organism above). CO

A 2n=4 plant is heterozygous at two genes, one controlling plant height (T = tall, t= short) and one controlling disease resistance (D = resistant, d = susceptible). The plant height gene is located on one chromosome, and the disease resistance gene is located on the other chromosome. In the cells below, draw to two possible arrangements of the chromosomes at metaphse I of meiosis. Hint: look at Figure 2.17 in your textbook for an example of how chromosomes can be arranged at metaphase I. Be sure to label the alleles present at the genes on the two chromosomes in each drawing. 00

Deduce the phenotypic proportions in the progeny of thefollowing crosses of autotetraploids in which the a+/a locus is very close to the centromere. (Assume that the fourhomologous chromosomes of any one type pair randomly two by two and that only one copy of the a+ allele isnecessary for the wild-type phenotype.)a. a+/a+/a/a × a/a/a /ab. a+/a/a /a × a/a/a/ac. a+/a/a /a × a+/a/a /ad. a+/a+/a /a × a+/a/a /a

A man who is a carrier of a translocated 15/21 chromosome marries a genotypically normal woman. a. Show the possible gametes that will be formed by this man if the translocated 15/21 chromosome synapses with chromosome 21 at Prophase I.

Two plants in a cross were each heterozygous for two gene pairs (AB/ab) whose loci are linked and 10 map units (mu) apart. (Recall that 1 mu is equal to 1% recombination between two genes.)   Assuming that crossing over occurs during the formation of both male and female gametes and that the A and B alleles are dominant, determine the phenotypic ratio of their offspring. Part D If the two genes are 15 mu apart and the plant is  (Ab/aB), what proportion of gametes from a signal plant will be ab? Part E What proportion of the offspring of two plants ( both  (Ab/aB)) will be A_B_ if the genes are 15 mu apart? Part F What proportion of the offspring of two plants ( both  (Ab/aB)) will be A_bb if the genes are 15 mu apart? Part G What proportion of the offspring of two plants ( both  (Ab/aB)) will be aaB_ if the genes are 15 mu apart? Part H What proportion of the offspring of two plants ( both  (Ab/aB)) will be aabb if the genes are 15 mu apart? How would I solve these?

Two plants in a cross were each heterozygous for two gene pairs (AB /ab) whose loci are linked and 30 map units (mu) apart. (Recall that 1 mu is equal to 1% recombination between two genes.) Assuming that crossing over occurs during the formation of both male and female gametes and that the A and B alleles are dominant, determine the phenotypic ratio of their offspring. Part E: What proportion of the offspring of two plants (both (AB/ab ) will be A - B- if the genes are 30 mu apart? Part F: What proportion of the offspring of two plants (both (AB/ab)) will be A - bb if the genes are 30 mu apart? Part G: What proportion of the offspring of two plants (both (AB/ab)) will be aaB- If the genes are 30 mu apart? Part H: What proportion of the offspring of two plants (both (AB/ab)) will be aabb if the genes are 30 mu apart?

In corn, the genes v (virescent seedlings), pr (red aleurone), and bm (brown midrib) are all on chromosome 5, but not necessarily in the order given. The cross: v+ pr bm/ v pr+ bm+ with v pr bm/ v pr bm produces 1000 progeny with the following phenotypes: v+ pr bm 226 v pr+ bm+ 229 v+ pr bm+ 153 v pr+ bm 185 v+ pr+ bm 59 v pr bm+ 71 v+ pr+ bm+ 36 v pr bm 41   What is the gene order, and the (b) genetic map of these three genes?