McMaster Bio 1M03: Exam 2024/2025 Questions with all the correct Answers ;( Real actual exam)

McMaster Bio 1M03: Exam 2024/2025 Questions with all the correct Answers ;( Real actual exam) Why might Pasteur's experiment be inconclusive? - Correct Answer The swan-necked flask broth may not support cell growth, or the broth was poisoned. Experiment did not confirm hypothesis that all cells come from pre-existing cells Why are replicates important in experiments? - Correct Answer To ensure that results were not achieved by random chance What is the definition of a replicate? - Correct Answer Unit that shares a common thing (4 mice in one cage = 1 replicate) What does the law of succession suggest? - Correct Answer As one species disappears, a similar one appears. Suggests ancestors and descendants What is the difference between vestigial traits and transitional features? - Correct Answer vestigial - useless features similar to useful features in related species (eg, coccyx in humans, tail in monkeys) transitional - intermediate feature seen in fossil species, between ancestral and descended species (eg, aquatic animal fins, tetrapod limbs) List potential outcomes of the bottleneck effect - Correct Answer - Potential high frequency of deleterious alleles that were previously at low frequency in source population - Different allele frequencies from source population, could lead to speciation - Strong genetic drift due to small population size Explain how the tuberculosis bacteria underwent natural selection during and after drug therapy - Correct Answer Variation: different strains → some resistant to drugs, some died Heritability: drug-resistant bacteria passed drug-resistant gene to daughter cells Differential fitness: bacteria that survived produced offspring Selection: drug-resistant allele had higher chance of survival through drug therapy