Concept explainers
To analyze:
The insects which have two wings are classified as dipterans. Dipterans are supposed to evolve from a four
Introduction:
Drosophila is a model organism for the study of development. It has a well studied genome sequence. Multiple genes are involved in the development of drosophila. Hox gene product functions as a transcription factor for homeobox gene (ultrabithorax and Antennapedia gene complex). In Drosophila, antennapedia is a hox gene that controls the formation of legs during development. It consists of five hox genes which work in combination for the development of cephalic and thoracic parasegments. Bithorax complex is a group of homeotic genes that regulator the differentiation of abdominal and post thoracic segments.
Want to see the full answer?
Check out a sample textbook solutionChapter 18 Solutions
Genetic Analysis: An Integrated Approach (3rd Edition)
- The path of whale evolution has involved the reduction or loss of several traits that are still prominent in most other mammals. TRUE (1) or FALSE (2). In terrestrial mammals, the sense of smell (olfaction) involves receptor proteins encoded by a number of genes. Whales don't have a sense of smell underwater, but their genomes still contain copies (pseudogenes) of some of these olfactory genes in their genomes. Because they are still present in whales' genomes, these genes must serve some other function in whales. Whales have some vestigial features like muscles that are attached to external ears in other mammals, even though whales have lost their external ears. Humans also lost some traits (e.g., body fur) and also have some vestigial traits, such as a mechanism to cause fur to stand on end even though we are mostly hairless (i.e., arrector pili muscles that produce goosebumps). Some features like hindlimb buds and whiskers are observed…arrow_forwardT or F a)Quadrula and Radiatula each have glochidia that are unhooked – this must be a result of convergent evolution (e.g. homoplasy). b)The common ancestor of Parreysiinae mussels definitely had 'Unhooked' glochidia. c)Note that Mytilus, Mercenaria, and Neotrigonia are mussels that do not have glochidia larvae - they still have larvae, but they are distinct from the other taxa in this tree. Given this, it is unlikely that the common ancestor of all mussel taxa represented in this tree had glochidia larvae.arrow_forwardPropose a hypothesis that could explain the following observation. A graduate student performing studies on mutations in drosophila (fruit flies) discovered a strain of flies with a silent mutation in the gene controlling the shape of the wings. Further investigation has shown that this mutation is lethal in flies who are homozygote. Flies that are homozygote wild type or heterozygote can develop and are able to survive.arrow_forward
- What is trichomacy in primates and why is this considered a beneficial mutation?arrow_forwardSpirochaetes are free-living, anaerobic bacteria that contain spiral-shaped cells. Nematodes are roundworms that are incredibly diverse and, as a group, have adapted to survive in all environments. Which of the following statements accurately describes the DNA of both groups? A. The spirochaete genome is smaller than the nematode genome. B. Nematode DNA is circular. C. Spirochaete chromosomes are composed of just DNA while nematode chromosomes also include specialized proteins. D. Spirochaete DNA is linear.arrow_forwardHow are the mammalian Hox genes related to the homeotic genes of Drosophila? How do the Hox genes contribute to morphological diversity in vertebrates, give an example.arrow_forward
- The hair keratin gene KRTHAP1 was lost in the human lineage. Keratins are a major component of hairs. Humans still have nine functional type I hair keratin genes but the loss of that particular gene may have caused the thinning of human body hair. The gene loss occurred relatively recently in human evolution—less than 240,000 years ago. What does this tell you about the possible phenotypic appearance of the humanoids living at that time? a. Denisovans likely had excessive body hair. b. The immediate precursors to anatomically modern humans must have been extremely hirsuit. c. We would expect to see a significant diminution in body hair in the hominids living around 240KYA consistent with the loss of this gene. d. Neanderthals probably had thick wooly manes of body hair. e. Homo ergaster probably had no body hairarrow_forwardYou are a researcher studying birds in an Indonesian rainforest. You have just discovered two new species whose beaks are markedly different, which you have named Laetiphonia orthorhynchus and Laetiphonia rhamphis. In particular, the beaks of L. orthorhynchus are very long, straight and pointed, whereas L. rhamphis have beaks that are quite short, wide and curved downwards. In further studies, you find that the same gene codes for beak shape in both species. In your own words, explain at least two ways that changes in gene expression could result in the differences you observe between these two species. Make sure to be specific in how your explanation applies to the bird species in this example.arrow_forwardAn adult human has a flat face with a small jaw and large cranium. An adult chimpanzee has a large jaw and small cranium. Both juvenile chimps and humans have heads similar to adult humans. Which of the following is a reasonable explanation for this pattern? Group of answer choices A) genes that modify skull shape are not expressed in chimps during development B) head shape is controlled by cytoplasmic determinants C)genes that modify skull shape are not expressed in humans during development D) chimps and humans have completely different genes controlling the formation of the headarrow_forward
- Runt is a Drosophila gene involved in development. Mutation of runt leads to an embryonic lethal phenotype in which every other segment in the body plan is missing. What class of developmental genes does runt belong to? O a) Pair-rule genes O b) Segment polarity genes Oc) Homeotic genes O d) Gap genesarrow_forwardYou have identified a Drosophila gene that is expressed exclusively in the odd-numbered "stripes" in the cellular blastoderm. Assuming that this gene is not redundant, what would be the most likely phenotype cause by a loss-of-function mutation in this gene? an embryo missing odd numbered segments an adult fly with a second pair of wings instead of halteres an embryo with two anterior ends an embryo missing even-numbered segments an embryo missing larval segments 3-10arrow_forwardHow, specifically, is the concept of ALLOMETRY relevant to the phylogenetic position of Homo floresiensis? Because if allometry explains the anatomy of Homo floresiensis then we can conclude that it is not separate species but instead a member of our species. Although most mammals on islands go through a process of getting smaller, Homo floresiensis evolved from a smaller ancestor to be bigger, meaning that allometry is an important factor. Mutations in the allometry allele are associated with many of the characteristics of Homo floresiensis. Because Homo floresiensis is so much smaller than other members of the genus Homo, it is important to determine how shape changes associated with smaller size impacted the species. Because Homo floresiensis had both small- and large-bodied forms, variation within the species is in large part dictated by allometry.arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education