Life Science Midterm Review Questions PDF

Main Ideas 1. Scientific Thinking 2. Evolution and Natural Selection 3. Nature, Nurture and Norm-of-Reaction 4. Genetics 5. Kin Selection and Reciprocal Altruism Practice Questions Scientific Thinking 1. What is scientific thinking and how d...

Main Ideas 1. Scientific Thinking 2. Evolution and Natural Selection 3. Nature, Nurture and Norm-of-Reaction 4. Genetics 5. Kin Selection and Reciprocal Altruism Practice Questions Scientific Thinking 1. What is scientific thinking and how does it work? Scientific thinking is a structured way of finding information on observable events in nature. It enables us to learn and understand about anything and allows us to reject hypotheses about how the world works. It works through making observations, formulating hypotheses, making predictions and conducting experiments. 2. How does a hypothesis differ from a theory or a prediction? A hypothesis is a suggested prediction of a possible correlation among two things. A theory is a tested, proven explanation for a set of factors. Predictions can lead to hypotheses and potentially theories through testing. 3. What does it mean to control an experiment? Controlling an experiment means to manage all variables in a study ensuring only the independent variable is changed while all other factors are kept constant. This ensures they’re aren’t any underlying factors within the experiment. 4. Compare and contrast superstitions, anecdotal observations and pseudoscience. Superstitions, anecdotal observations and pseudoscience are all examples of unscientific thinking. Superstitions are unjustified beliefs in supernatural causation, anecdotal observations are convenient but not based on careful study and pseudosciences are misconceptions. 5. With more and more observations that support a hypothesis, can you eventually say it is true? No you can never really say a hypothesis is true because information is always changing and advancing. Supportive evidence increases a hypothesis, but it cannot be considered true. Hypotheses can be rejected or modified based on further analysis, but they can never be proven true 100% of the time. Evolution and Natural Selection  6. What is evolution and how does it occur? (Name the four ways and give an example) Evolution is a gradual change to a better or more complex form and it occurs when there is a change in allele frequency within a population. There are four main ways through which evolution occurs: genetic drift, natural selection, mutation and gene flow. An example is farmers getting more milk from cows by only breeding the top 20% of milk producing cows. 7. What is natural selection? Natural selection is when a species changes to better fit to its environment. In order for natural selection to occur there must be variability, heritability and differential reproductive success. 8. What ideas and observations influenced Darwin? Darwin noticed unexpected patterns in the galapagos island among the finches. There were different finch variations, similarities between fossils and living species, offspring overproduction, competition for resources and the inheritance of traits. 9. Why does artificial selection almost always work? Artificial selection is a process where humans choose organisms with specific traits to breed, in order to enhance those traits in future generations. It almost always works because it works the same as natural selection since there is variability, heritability, and differential reproductive success even if the traits being passed down are determined artificially (by humans) and not by nature. 10. How is genetic drift related to Mendel’s first law? Genetic drift is related to Mendel’s first law because both involve the random distribution of alleles within a population. 11. What is sexual selection and why does it lead to trade offs? Include and example Sexual selection is a type of evolution in a population (change in allele freq) in which a species has more reproductive success when it exhibits certain exaggerated trait. This leads to trade offs because reproductive success becomes more important than survival. An example of this are peacocks and their giant feathers. The bigger and more colorful the male peacock’s feathers are the more likely a female with choose to mate with them however these large feathers also make it easier for predators to attack the make peacock. Nature, Nurture and Norm-of-Reaction 12. What is the norm of reaction and how does the slope describe the relation between genotype and phenotype?  The norm of reaction is the set of all phenotypic expressions possible for a given genotype if raised under all possible different environmental conditions. The norm of reaction graph represents the relationship between genotypes and phenotypes. The x-axis in the graph represents the environment and the y axis in the graph represents the possible phenotypes. The data lines on the graph represent the different genotypes being tested. If the slope is steep, that means the environment plays a large role in the change of the organism’s phenotype. 13. What is evolutionary fitness Evolutionary fitness is the relative reproductive success of a phenotype or genotype. Alleles that confer highest fitness on the individuals carrying them will increase their market share in a population. Critical to assessing fitness is understanding that it is measured: 1. Relative to other geno/phenotypes in the population 2. In a specific environment 3. By reproductive success. 14. What is evolutionary mismatch? Include an example. Evolutionary mismatch is when the environment changes too fast or an individual is taken out of adapted areas. For example, humans before were accustomed to the hunter gatherer lifestyle so we were biologically programmed to eat when we could due to the limited food. However now we don’t have a limited supply of food so people can actually over eat and not be able to manage their weight. Genetics 15. How do dominant and recessive alleles differ? Dominant alleles only require one allele in a pair in order for it to display the trait it holds whereas a recessive trait requires both alleles in a pair for it to display the phenotype. 16. How do you use probability to determine inheritance of a trait? With Mendel’s law of segregation and through calculating the coefficient of relatedness in pedigrees. 17. How does Mendel's first law explain why offspring look like their parents? Mendel’s first law explains why offspring look like their parents because it states a gamete receives only one allele for each gene (one from each parent). 18. How do you predict offspring genotypes of sex linked traits? All sexlinked traits will always be held within the sex chromosomes which is also known as the x chromosomes. Ex) Color blindness is carried on the x chromosome. Females are carriers and males are more likely to have color blindness due to only having one x chromosome.  19. **Analyze pedigree pic 20. How does biological sex determination among species vary? In mammals females have two of the same sex chromosomes, turtles have different sex chromosomes but the way sex is determined is through temperature. In bees and wasps the males are haploid and females are diploid. 21. Does having a particular genotype esure you will have a particular phenotype? No, having a particular genotype does not ensure you will have a particular phenotype because it is possible for an organism to carry a gene/allele but not display it. 22. Using blood types, explain how multiple alleles in a population come together. There are four possible blood types, A, AB, B, and O where A and B are dominant over O and are codominant to one another. A person with a phenotype of A may have a genotype of AA or AO. A person with a phenotype of B could have a genotype of BB or BO. A person with a phenotype of AB can only have a genotype of AB. And lastly if a person has a phenotype of O their genotype would have to be OO. Kin Selection and Reciprocal Altruism 23. What are fitness and inclusive fitness? How do Belding’s ground squirrels help us understand this? Fitness refers to an individual’s reproductive success or the number of offspring or genes that contribute to the next generation. Inclusive fitness refers to an organism's total fitness, which is equal to their direct fitness plus their indirect fitness. Indirect fitness is fitness gained by aiding survival and reproduction of non-descendant kin, like siblings or other relatives. Belding’s ground squirrels help us understand the idea of inclusive fitness because some squirrels, usually older females, put themselves in danger by yelling when a predator is approaching. By issuing the warning she decreases her own chances of survival. In these squirrels inclusive fitness is more important than their own direct fitness. 24. What does Hamiliton’s rule help us understand? Hamilton’s rule helps us understand when and why individuals should exhibit apparent altruism toward genetic relatives. It tells us why we look out for siblings more. 25. Describe the evidence in support of Hamilton’s rule The greater someone’s coefficient of relatedness is to someone else, the more likely they are to exhibit kindness towards them. For example it is much more likely for a person to murder a stranger than it is for them to murder a family member. A person is  also much more likely to lend money to a relative than a person they have no relation to. People who live together who are not related by blood are 11 times more likely to kill each other. Step children are 100 times more likely to be killed by a step parent than a biological child. 26. How do you calculate coefficients of relatedness? Why is it important? To calculate coefficient of relatedness, you first go up the pedigree and then back down to the desired relative. You must always start by going up and you cannot zig zag up and down. Go up as far as you can and then go down on the path towards the relative. Every time you pass through a relative you multiply by 0.5. All paths are created equal. You must include every possible path, you add up the total of each path to solve for r. The coefficient of relatedness is important because it is a quantitative measure of how closely two individuals are genetically related and we can predict behaviors based on kinship. 27. What is the difference between altruism and apparent altruism? Altruism is the act of kindness or selflessness and apparent altruism is when an act looks like altruism however it actually benefits the person acting selflessly more. Natural selection produces apparent altruism not true altruism. 28. Under conditions should we see reciprocal altruism? We should see reciprocal altruism when you assume they’re going to return the favor, when it is more likely to concur and when you have repeated interactions with them. 29. What are rules of thumb and how are they relevant to evolution and behavior? Natural selection causes us to have rules of thumbs for a lot of different things. It is when we do what is best to increase our own fitness. 30. Describe 3 strategies to increase cooperation among unrelated individuals Tinker with the perceived costs and benefits. - Reduce the perceived cost to the other person - Accentuate the benefit that you’ll receive from the cooperation Distinguish cheaters and kind people - Facilitate the building of reputations - Use “honest signals” that can’t be faked - Keep track of and punish cheaters Reduce the perceived vulnerability of partners - Make the first step: gifts - Acknowledge 31. What is the ultimatum game? How does it help us understand reciprocal altruism and our sense of fairness? The ultimatum game variations are strong evidence supporting our view that human brain machinery is built to maintain relationships.