Sisters U QO The red arrows are pointing at A Sisters U Homologs Sisters and Homologs Neither sisters nor homologs U A Homologs Sisters and Homologs Neither sisters nor homologs A The black arrows are ointing at A P P U

An organism described as 2n=4 has the chromosomes below with genes indicated by letters and centromeres indicated by periods. Select the BEST description of the chromosome aberration present in this organism. EGHI.LNP El.LNP QTWZ QTWVZ Select one. O a. Pericentric Inversion O b. Homobrachial Displaced Duplication O c. Interstitial Deletion O d. Robertsonian Translocation O e. Reverse Tandem Duplication Of Terminal Deletion O g. Heterobrachial Displaced Duplication O h. Tandenm Duplication O Nonreciprocal Translocation 01 Reciprocal Translocation Ok. Paracentric Inversion

Which letter is pointing at the centromere region? В A C

Identity gene 1 (bl, pr, vg) Identity gene 2 ( bl, pr, vg) Identity gene 3 ( bl,pr, vg) How many map units separate genes 1 and 2 ( Distance 1)? How many map units separate genes 2 and 3 ( distances 2) ?

Find the correct order of the genes on the chromosome

Let's suppose that a normal chromosome carries genes labeled A through /. The centromere is located between genes B and C. As shown below, a chromosome with an inversion has a region where the order of certain genes is reversed. Note: The genes on the inverted chromosome carry recessive alleles that are designated with lowercase letters. Normal chromosome: A B Centromere C D E F G H I Chromosome with an inversion: a b Centromere c d h g fei A. If you ignore possible fertility issues, do you think this individual will otherwise be phenotypically normal or abnormal? Explain why. B. Let's suppose a single crossover during meiosis occurs between these two homologs in the region between genes F and G (and between g and f). Following the crossover, what is the order of genes (designated with upper and lower case letters) on the two resulting chromosomes. Include centromeres in your answer. Hint: Both of the resulting chromosomes will carry gene deletions and gene duplications.

A chromosome had these parts in this order: A   B   C    D    E    F    G. Then something happened to it. Now it looks like this: A   D    C    B   E    F    G. What happened to it? translocation deletion duplication inversion A chromosome had these parts in this order: R   S   T   U   V   W. Then something happened to it. Now it looks like this: R   S    S   T     U    V    W.  What happened to it inversion translocation duplication deletion

Which of the following is unable to form a linkage group? O genes that are not located on the same chromosome O genes that are located on the same chromosome O genes that are more than 17cM apart from one another

uh ec CV + + 10.5 SC 9.1 scute bristles echinus eyes 9.2 ct + crossveinless wings Table 1: phenotype wild-type tapdance feet crossveinless wings tapdance & crossveinless cut wings 15.9 vermilion eyes V + + 66.8 Drosophila X chromosome Use the map provided above for problems 1 & 2. Problem 1: 11.2 10.9 garnet eyes M A new gene is being investigated in fruit flies. The recessive allele of this gene (t) causes the flies' feet to grow tiny tapdance shoes, while the dominant allele (t*) permits wild-type feet to develop. Preliminary studies indicate that this new gene is located on the X-chromosome. You decided to perform a two-point testcross to determine its position relative to the well-established crossveinless wings gene (cv). You cross a female heterozygous for both genes with a testcross male fly and obtain the male offspring results shown in table 1, below. Using this information, answer the following questions: # male offspring 13 405 401 11 forked bristles a) is the original…

In Figure 4-10, what is the mean frequency of crossoversper meiosis in the region A–B? The region B–C?