BIOL 123N ODU EXAM 1 Questions and Answers

BIOL 123N ODU EXAM 1 Questions and Answers What is evolution? The biological change over generations. Which biological molecule endows biological systems with an intrinsic ability to change over generations? DNA Which property of a molecule enables change? The alleles What is artificial selection? The process of modifying organisms by selection in breeding by humans. What is an allele? Two or more alternate forms of gene because of mutation, that are found on the same place on a chromosome. What is a genotype? The genetic makeup of a cell. What is a phenotype? The observable genetic characteristics of an individual What is natural selection? A process where organisms adapt over time to their environment to survive and produce more offspring. Which human traits have increased in frequency over generations due to natural selection? The improvement of the ability to catabolize carbohydrates and the ability to metabolize toxins in things we ingest. Why is genetic variation necessary for natural selection to occur? The best genetic traits aid the succession of organisms in future generations T/F: alleles that INCREASE reproduction in the current environment ALWAYS INCREASE in frequency in future generations. True What is the purpose of natural selection? To produce individuals that are better adapted to survive in the current environment. T/F: Natural selection produces the perfect individual in a species. False Which evolved mental illness reduced risk of infectious disease and improved immunity? Obsessive-Compulsive Disorder Why do some alleles increase the risk for depression? They improved reproduction in the past environments by increasing impulsive behavior, creativity, intellect, interest in sex, ability to survive long winters(MENTAL HIBERNATION) What is 'heterozygote advantage'? The heterozygous genotype has a higher relative fitness than either the homozygous dominant or homozygous recessive genotype Example of heterozygote advantage in humans? One copy of sickle cell allele or one copy of beta-thalassemia allele increase resistance to malaria and increase reproduction in environments with malaria. Which heterozygote advantage reduces the risk of Chlorea, Tuberculosis, and Typhoid Fever? One copy of the Cystic Fibrosis allele What is Group Natural Selection? Populations consisting of individuals showing cooperative behavior reproduce better than those without cooperative behavior. What is inter-sexual selection? When the females choose male mates based on flamboyant traits. What is intra-sexual selection? Males compete with males to mate with females. What percentage of all immune cells reside in the digestive tract? 70% Benefit of "bitter" taste sensors: Sense toxic plant compounds and bacterial compounds Benefit of "salty" sensors: Avoid drinking sea water. What is a purpose of morning sickness? Reduce risk of exposing the fetus to toxins in food and drink. Why do we benefit from pain and fear? Protects us from harm or situations that would cause harm. What is a metapopulation? A group of local populations that inhabit, and move among, suitable habitat patches within a larger geographic range. What is the benefit of taste and smell? To prevent organisms from ingesting harmful or toxic foods What is a population? A group of individuals of a single species that inhabits a defined area at a specific time. What is ecology? The study of how viruses, single-cell species, and multi cell species interact. What type of behavior is shown by uniform dispersion? Aggression What type of behavior is shown by clumped dispersion? Cooperative behavior