In C. elegans there are two sexes: hermaphrodite and male. Sex is determined by the ratio of X chromosomes to haploid sets of autosomes (X
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Genetic Analysis: An Integrated Approach (3rd Edition)
- About 40% of Solomon Islanders carry a gene for blond hair, and yet only 5%–10% of these people actually have blond hair. Why is the number of people with blond hair only 5%–10% when so many people carry genes for blond hair? The duck-billed platypus has a unique mechanism of sex determination: females have five pairs of X chromosomes (X1X1X2X2X3X3X4X4X5X5) and males have five pairs of X and Y chromosomes (X1Y1X2Y2X3Y3X4Y4X5Y5). Do you think each of the X and Y chromosome pairs in males assort independently of other X and Y pairs during meiosis? Why or why not? How is the inheritance of X-linked traits different from the inheritance of autosomal traits? How is the inheritance of X-linked and autosomal traits similar? List as many differences and similarities as you can.arrow_forwardIf red vizcacha rats (Tympanoctomys barrerae) have 100 autosomes and 2 sex chromosomes in each of their diploid somatic cells, then they must have: only 102 chromosomes in their haploid germ cells only 100 chromosomes in their haploid germ cells only 52 chromosomes in their haploid germ cells only 51 chromosomes in their haploid germ cells only 50 chromosomes in their haploid germ cellsarrow_forwardWhich of the following would not be considered a component of sexual reproduction? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer a Production of eges and sperm in separate sexes in an animal species b. Gradual acquisition of multiple mutations in a purely mitotically dividing eukaryotic single celled organism Occasional production of diploids through fusions of cells of opposite mating types in a yeast that largely reproduces through clonal mitotic divisions "Alteration of generations" between haploid and diploid organisms in a fernarrow_forward
- One reason that worker bees forgo their own reproduction to help their sister (the queen) reproduce is that female bees are more closely related to their sisters than they are to their own offspring. This quirk of genetics results from the fact that bees have haplodiploid sex determination, in which females are diploid, with a mother and a father, but males are haploid, developing from unfertilized eggs. Because males are haploid, they produce sperm by mitosis. Explainwhy haplodiploid sex determination causes females to be more closely related to their sisters than to their offspring.arrow_forwardIn reptiles, sex determination was thought to be controlled by sex-chromosome systems or by temperature-dependent sex determination without an inherited component to sex. But as we discussed in section 7.6, in the Australian lizard, Pogona vitticeps, it was recently revealed that sex is determined by both chromosome composition and by the temperature at which eggs are incubated. What effects might climate change have on temperature- dependent sex determination in this species, and how might this impact the sex ratio for this species in subsequent generations?arrow_forwardFor each of the following, identify what characteristics of a species male and female karyotype would indicate that mechanism of sex-determination. Genic XY sex chromosomes ZW sex chromosomes Haplo-diploid genomes XO sex chromosomes Environmental [Choose ] [C [C [C [C [C ✓ [Choose ] More than one answer is correct Females have one more chromosome compared to males Females have twice as many chromosomes compared to males Females show a pair of differentiated sex chromosomes Males show a pair of differentiated sex chromosomes No visible differencearrow_forward
- note: the cirled answer might be right or wrongarrow_forwardWhich of the following is true about sex determination in mammals? Choose all possible answers. a.) The conversion of the genital ridge into the bipotential gonad requires the Sf1, Wt1, and Lhx9 transcription factors. b.) Even if one of the transcription factors mentioned in choice a (Sf1, Wt1, and Lhx9) will lose its function, the normal development of either male or female gonads will still push through. c.) Sry protein binds to the enhancer of the Sox9 gene and elevates expression of this key gene in the ovary-determining pathway. d.) β-catenin functions to initiate the ovarian pathway of development by activating the genes involved in granulosa cell differentiation. e.) Sf1 protein prevents the production of Sox9.arrow_forwardExplain in 7-8 sentencesarrow_forward
- Suppose that you found a species S. ambivala that is closely related to S. latifolia, such that they share the same Y chromosome marker. However, S. ambivala is hermaphroditic. What would you expect to see on your gel, if you had taken twenty randomly chosen S. ambivala plants, and performed the same experiment?arrow_forwardThe amount of DNA in a differentiating oligodendrocyte in M-phase is 210pg. How much DNA would be present in Go? Briefly describe the expected cellular function during this stage How much DNA would be present in G₂? Briefly describe the expected cellular function during this stage. What is the number of chromosomes during gametogenesis if you have eight chromosomes at Meiosis I? What is the amount of DNA in a spermatozoa cell? a. 1x b. 0.5X C. 2X d. 0.25X 688 words IX English (United States) Focus. Earrow_forwardThe purple sea urchin (Strongylocentrotus purpuratus) and a sympatric species known as the red sea urchin (Strongylocentrotus franciscanus) release their gametes into the Pacific Ocean at the same time, but the sperm cells of each species fail to fertilize the egg cells of the other species due to different membrane proteins. This prevention of interspecific fertilization in sea urchins is: a post-zygotic barrier known as F1 hybrid inviability a pre-zygotic barrier known as habitat isolation a post-zygotic barrier known as F1 hybrid sterility a pre-zygotic barrier known as gamete isolation a pre-zygotic barrier known as temporal isolationarrow_forward
- Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning