Evolutionary Biology Ploidy and Meiosis: The basis for recombination by Devin Reese, PhD. Reading Quiz Teach with this We detect life on Mars and determine that it's a single-celled organism reproducing asexually. Based on what we know of life on Earth, which of the following is most likely? The organism has no DNA. The organism is haploid. The organism is diploid. The organism is polyploid. Most vertebrate animals are diploid, with two copies of each chromosome. true false How does sexual reproduction, along with diploidy, help ease the mutational load? By ensuring organisms have an extra copy of every "good" gene. By limiting the speed of genetic change in a population of organisms. By ensuring mutations in genes have overall positive impacts. By limiting the occurrence of mutations by keeping cells younger. What does ploidy have to do with genetic "experimentation"? Having multiple chromosomes makes organisms more risk-taking. Having multiple chromosomes makes organisms less risk-taking. Having more gene copies leads to slower genetic change in populations. Having more gene copies leads to faster genetic change in populations. Climate change, by making environmental conditions harsher, is likely to ultimately favor sexual reproduction. true false What process "compensates" for the chromosome doubling in sexual reproduction? Fertilization Meiosis Mitosis Crossing over What is depicted in this diagram? CC BY Rlawson at en.wikibooks Meiosis because it concludes after a parent cell divides into two daughter cells. Mitosis because it concludes after a parent cell divides into two daughter cells. Meiosis because a parent cell divides into two daughter cells, followed by a second division to yield four. Mitosis because a parent cell divides into two daughter cells, followed by a second division to yeild four. Does this larval zebrafish likely have haploid or diploid cells? CC BY-NC 2.0 Oscar Ruiz and George Eisenhoffer, University of Texas MD Anderson Cancer Center, Houston It must be haploid because all vertebrates are haploid. It must be haploid because it's in a larval form, not yet adult. It must be diploid because all vertebrates are haploid. It must be diploid because it's in a larval form, not yet adult. Alternation of generations only happens in recently evolved plants. true false Based on this depiction of a slime mould life cycle, which of its lifestages is equivalent to the fern with fronds? CC BY 4.0 By CNX OpenStax Flagellates Amoebae Plasmodium Sporangium Do animals have alternation of generations, like in plants? Arguably yes, but with the haploid stage dominant. Arguably yes, but with the diploid stage dominant. No, because most animals have only haploid life stages. No, because most animals have only diploid life stages. Meiosis, with the recombination it entails, is the only viable strategy for survival of species in the long run. true false Score Quiz