Concept explainers
A small population of deer living on an isolated island are separated for many generations from a mainland deer population. The populations retain the same number of chromosomes and but hybrids are infertile. One chromosome (shown here) has a different banding pattern in the island population than in the mainland population.
Describe how the banding pattern of the island population chromosome most likely evolved from the main-land chromosome. What term or terms describe the difference between these chromosomes?
Draw the synapsis of these homologs during prophase I in hybrids produced from the cross of mainland with island deer.
In a
Suppose that
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Genetic Analysis: An Integrated Approach (3rd Edition)
- The radish (Raphanus sativus) has a diploid number (2n) of 18. The cabbage (Brassica oleracia) also has a diploid number (2n) of 18. Why is it that if you cross these two species to produce a hybrid with a total of 18 chromosomes in its somatic cells it is sterile, but if you form an allotetraploid (also known as amphidiploid) from these two species it is fertile?arrow_forwardSuppose researchers studied the first chromosome of a new species and mapped three genes of interest, indicated as a, b, and c. A three‑factor cross was performed and the number of gametes formed from the F2 generation was recorded in a table. Note that the order of genes in the table is arbitrary. Calculate the recombination frequencies for each given gene pair in map units. ?+ ?+ ?+ ? ? ? ? ?+ ?+ ?+ ? ? ? ?+ ? ?+ ? ?+ ? ? ?+ ?+ ?+ ? 173 176 35 33 11 10 3 1 After completing the gene mapping, the researchers treated individuals to induce inversions in the chromosomes. After treatment, another three‑factor cross was performed and the number of gametes formed from the F2 generation was recorded in a second table. Note that the order of genes in the table is arbitrary. ?+ ?+ ?+ ? ? ? ? ?+ ?+ ?+ ? ? ? ?+ ? ?+ ? ?+ ? ? ?+ ?+ ?+ ? 188 185 24 26 1 0 49 46 Calculate the recombination frequencies for each given gene pair in map units.arrow_forwardIn an electrophoretic gel across which is applied a powerful electrical alternating pulsed field, the DNA of the haploid fungus Neurospora crassa (n = 7) moves slowly but eventually forms seven bands, which represent DNA fractions that are of different sizes and hence have moved at different speeds. These bands are presumed to be the seven chromosomes. How would you show which band corresponds to which chromosome?arrow_forward
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- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning