BIOLOGY 142 test 1 delgado Questions And Answers With 100% Correct Answers

3. ________ isolating mechanisms prevent the fusion of gametes where as _______ isolating mechanisms prevent the proper functioning of the zygote. - Prezygotic, post zygotic • Adaptive radiation - o Existence of groups of closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment. This is common in situations in which species occur in an environment with few other species and many available resources. o Adaptive radiation requires both speciation and adaptation to different environments o Galapagos, mammalian evolution ▪ For natural selection to occur and result in evolutionary change, three conditions must be met: - 1. Variation must exist among individuals in a population. 2. Variation among individuals must result in differences in the number of offspring surviving in the next generation. 3. Variation must be genetically inherited 1. The formation of one or more new species from an ancestral species called? - speciation 12. If a population of organisms natural selection favored both smallest and largest? - Disruptive selection 13. What is it called when two species maintain reproductive isolation by using different components of a habitat? - Ecological isolation 14. Lock and key fit of a dragonfly se organs is an example of - Mechanical isolation 15. Selection can reinforce reproductive isolation btw. 2 pop. By selecting against genes that would encourage interbreeding btw. The 2 pops.? - true16. Which of the following processes is geographic isolation a key component of ______ - Allopatric speciation 17. Disruptive selection occurring in two populations a=that aren't geographically isolated from each other could eventually lead to the formation of two new species - Sympatric speciation 18. Genetic drift, founder effects, and population bottlenecks can lead reproductive isolation - true 2. A species is a group or groups of actually or potentially interbreeding natural populations which are reproductively isolated from other groups. What is this statement>? - Biological species concept 20. The Cambrian explosion occurred about 500 million years ago before then there was no fossil evidence - false (p² + 2pq + q² = 1) - Hardy-Weinberg Equation Equation used to calculate future genotype proportions in a population 21. The idea that reproductively isolated populations slowly accumulate differences until speciation - gradualism 22. The idea that speciation occurs is a rapid bursts followed by long periods without change in species called - Punctuated equilibrium 4. Which of the following is the mechanism that drives evolutionary change? - Natural selection 5. If an organism improves a particular trait during its life time, would this trait be passed on to the next generation? - No, it wouldn't 7. Random changes in the nucleotide sequence of a gene is called? - mutation 8. Mating with relatives is an example of interbreeding - Decreases genetic diversity9. A pop. of cute furry animals is hunted for its fur. The regional gov. introduces legislation to protect animals and population rebounds. What is this an example of? - Bottle neck A pop of marine snails is found on a coral reef, there is variation in the shell thickness among individuals. What is this an example of? - Natural selection Alfred Wallace - using the scientific methods in southeast Asia, he writes Darwin about the butterflies and other things about evolution and calls it natural selection Allopatric speciation (most common form of speciation) - o Speciation where populations become geographically isolated o Geographically separated, are allopatric populations appear much more likely to have evolved substantial differences leading to speciation Ancestral characters - similarity among species that arose prior to the common ancestor of the group artificial selection - o Human induced initiated phenotypic changes in plants/ animals o Silver foxes have been artificially selected and are now known tamed dogs. b) Bottle neck effect - Few surviving individuals from an event contain a random genetic sampling of the original source population Genotypic variation can be depleted Northern elephant seal almost hunted into extinction Behavioral isolation - Different displays, songs, and pheromones Biogeography - the study of geographic distribution of life on earthBiological Species Concept- (Mayr, 1942) - Species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups. The biological species concept is composed of populations whose members mate with each other and produce fertile off spring or would do so if they came into contact with one another. Conversely, populations whose members do not mate with each other who cannot produce fertile offspring are said to be reproductively isolated and therefore, are members of different species. Bottle neck effect - - ▪ Few surviving individuals from an event contain a random genetic sampling of the original source population ▪ Genotypic variation can be depleted ▪ Northern elephant seal almost hunted into extinction Clade - species that share a common ancestor