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: INTEGRATED - ACCESS
- How 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_forwardThe 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_forwardWhich of the following best explains the number of similarities between the amino acid sequences of the Drosophila Hedgehog protein and the Chicken Indian Hedgehog protein? O A. The Drosophila hedgehog gene evolved from hedgehogs, which are distantly related to birds. O B. Both genes evolved from a gene present in the last common ancestor of Drosphila and chickens, and the number of differences reflects the amount of time that has elapsed during the evolution of these two lineages. a During the evolution of Drosophila and chickens, a hedgehog like gene arose independently in each lineage, then the gene that arose in chickens diversified. A These genes are unrelated, and the fact that they are similar is only because the proteins need to have similar biochemical properties. They are unrelated because chickens don't have segments and Drosophila larvae don't have limb buds.arrow_forward
- You 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_forwardThe platypus is one of a very small number of mammals that are venomous. Researchers compared the substances in the platypus venom to that of venomous reptiles. They found that the venom in platypus was derived from a protein called defensin, while that in many reptiles was based on a protein called crotamine. The protein structure of these molecules is remarkably similar, though they are controlled by unrelated genes in each taxa. Both molecules originated as non-toxic antimicrobial compounds. Part A: Venom in both platypus and reptiles is an example of: A. Homologous traits B. Analogous traits C. Adaptive radiation D. Genetic drift Part B: A trait matrix for the amniotes is below. Using the trait matrix, match the taxa to the letters at the branch tips. (see attached image) Using the image, match the taxa to the letters at the branch tips 1. Chicken 2. Kangaroo 3. Viviparity 4. Placenta Part C: In which location(s) did each trait evolve on the phylogeny? If more than one location…arrow_forwardVestigial wings Trait Wild-type Yellow Body White-eyes Eyeless Body Colour Gray Yellow Eye Colour Red Eye white Eyes absent Eyes absent Eye shape Normal Normal, Extends past tip of Small, Club- Wing shape and size shaped abdomen Antenna shape and size Normal Tan stripes at the end White end with Bristle shape and size stipes very unclear. Discuss the changes in chromosomes that contribute to the mutations tabulated in Table abovearrow_forward
- Explain how loss-of-function mutations in the following categories of genes would affect the morphologies of Drosophila larvae: A. Gap genes B. Pair-rule genes C. Segment-polarity genesarrow_forwardThe ancestor of cats was presumably homozygous for wild type at all of the described genes. What was the phenotype of this ancestral cat at each of these loci? 1)Dark grey with black mackerel stripes 2)Light grey female with dark grey mackerel stripes 3)Light brown male with chocolate tips 4)Black female with large white patches 5)Cream male with small white patches and orange mackerel stripes 6)A uniformly colored black catarrow_forwardAssume you are studying development in two species of iguana. You determine that a certain gene, "SPN2" turns on and off at different times in the two different species. The difference in timing leads to a different body length between the two iguana species. This phenomenon is an example of which of the following terms? a. Punctuated Equilibrium b. Pleiotropy c. Gene duplication d. Heterochronyarrow_forward
- To understand the genetic basis of locomotion in the diploid nematode Caenorhabditis elegans, recessive mutations were obtained, all making the worm “wiggle” ineffectually instead of moving with its usual smooth gliding motion. These mutations presumably affect the nervous or muscle systems. Twelve homozygous mutants were intercrossed, and the F1 hybrids were examined to see if they wiggled. The results were as follows, where a plus sign means that the F1 hybrid was wild type (gliding) and “w” means that the hybrid wiggled.a. Explain what this experiment was designed to test. b. Use this reasoning to assign genotypes to all 12 mutants. c. Explain why the phenotype of the F1 hybrids between mutants 1 and 2 differed from that of the hybrids between mutants 1 and 5arrow_forwarda) Explain how it can be the case that mutating a Homeobox containing gene has a large impact on the morphology of some trait, even though the evolution of that trait involved no changes in that gene. b) Explain how, even though they rarely change themselves, certain patterns of expression of Homeobox and MADS box containing genes facilitate morphological diversification in animals and plants.arrow_forwardBecause offspring inherit the mitochondrial genome only from the mother, evolutionarily the mitochondrial genome in males encounters a dead end. The mitochondrial genome in males has no significant impact on the genetic information of future generations. Scientists have proposed that this can result in an accumulation of mutations that have a negative impact on genetic fitness of males but not females. Experiments with Drosophila support this possibility. What experimental data or evidence would you want to evaluate or consider to determine if an accumulation of mtDNA mutations negatively impacts the fitness of males of any species?arrow_forward
- Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning