Bio 280 Final Exam Questions & Answers Already Graded A+

*The scenario: In a single, isolated population, mutations of each of the three types in options a-c below occur, and the resulting genotypes ultimately become fixed in that population. Other populations never experienced these mutations, so the original genotypes remain. Now we'll hybridize members of that isolated population to members from one of the others. -Which of the following types of mutation is MOST LIKELY to cause reproductive isolation as a side effect? - Large Inversion ( chromosomes don't align properly during meiosis) Could a population of organisms with one copy of each chromosome, such as a bacterial population, be in HW equilibrium? - NO, but they can be POLYMORPHIC Do any organisms have identical phenotypes? - NO Does speciation lead to Cladogenesis? - Yes, by far most speciation events involve the splitting of one lineage into two. Evolution only occurs by____ - Natural Selection EXAM 2 - EXAM 2 Example of the evolution of a trait via a function shift? - The flippers of penguins evolved from the wings of their flying ancestors. For a trait to be polymorphic it is necessary that... - a) there has to be more than one phenotype b)phenotypes can be sorted into discrete categories Gene flow occurs when individuals are carried from population to population and genetic drift occurs when - as individuals pass their genes along to future generations.Horizontal gene transfer... - is responsible when a novel gene appears in the genome of a species that is otherwise present only in distantly related species However that reproductive isolation evolved, what kind of geographic speciation would we typically call it? - Generally Allopatric Speciation, but best answer was PERIPATRIC Speciation Hybrid speciation occurs when... - ...hybrids between two species are able to breed with one another but not with either of the parent species If two alleles in a population are neutral the population will... - Evolve by genetic drift In the TV game show Jeopardy, host Alex Trebek gives just the answer to a question, and the contestants have to figure out the question. Here goes: Answer: Approximately 600 million years, give or take a few 100 million. What is the corresponding question? - How long did it take between the cooling of the planet and the origin of life? LUCA had... - DNA, Complex Metabolism, RNA, a simple plasma membrane Natural selection requires which 3 conditions? - 1. phenotypes are inherited 2. individuals differ in their phenotypes 3. some phenotypes have higher reproductive success tun others because of their differences One common criticism of natural selection is that it's based on circular reasoning - an elementary logical flaw where a conclusion is used as part of the evidence to 'prove' the very same conclusion. The criticism goes like this: [Evolutionary biologists] define natural selection as the survival of the fittest, but the fittest individuals are defined as those that survive. IS THIS CRITICISM VALID? - a) No, it's based on a misunderstanding: 'survival of the fittest' isn't the definition natural selection. b) No, it's based on a misunderstanding: the fittest individuals aren't necessarily those that survive.BOTH OF THESE ARE CORRECT The stronger stabilizing selection is on a trait, the ____ the molecular clock in it's underlying genes runs. - slower... What is a gene family? - A group of independently inherited genes that have similar DNA sequences but typically perform more or less different functions. THEY COME FROM GENE DUPLICATIONS, TYPICALLY WITH SOME MODIFICATION OF FUNCTION. What is an SNP map? - It marks the locations of sites in the genome where polymorphism has been found, specifically the places on the chromosomes where one nucleotide has been substituted with another. What results in adaptations? - Natural Selection What's a gamete? - It's an egg or sperm cell in animals, or pollen or ovule in plants, with one copy of each chromosome Whats the difference between the selection coefficient (s) and fitness? - fitness+s=1 OR fitness=1-s When a population is small an allele can become fixed even if it is highly deleterious? - True and the smaller the population, the more likely it is.