Factual Questions 1 Chromosome number is reduced during meiosis because the process consists of A two cell divisions and a single round of chromosome replication B a single cell division without any chromosome replication C two cell divisions without any chromosome replication D four cell divisions with no chromosome replication 5 A characteristic of K selected populations is A a high intrinsic rate of increase r B small offspring C many offspring per reproductive episode D offspring with good chances of survival E early parental reproduction 6 Formation of thick or thin hair shafts in an animal is controlled by a single gene with two alleles Thick hair is needed for survival in cold climates but not in warm climates Most animals in a population have thick hair Which allele for this trait is dominant A Thin hair B It depends on the climate C Thick hair D They are co dominant E It can t be determined with the information provided 2 Which statement best describes Mendel s law of independent assortment A Distribution of alleles for one pair of chromosomes is not affected by distribution of other chromosomes B During fertilization which sperm combines with which egg is random C Diploid organisms contain two copies of each chromosome that are homologous to each other D homologous chromosomes pair up during meiosis I E Mutations are random events which affect each chromosome independently 7 Which of the following is NOT needed for the Hardy Weinberg equation to successfully predict the genetic make up of a population A random mating among the population B equal reproduction rates among all individuals in the population C the population is large D there is no immigration or emigration E all individuals in the population are long lived 3 When setting up an genetic cross to ensure that you start with homozygous genotypes you should A Start with individuals which look very different from other individuals B Mate close relatives for many generations C Examine each individual very closely for signs of variation D Start with individuals who always produce offspring with the same phenotype as themselves 8 Which statement best describes the effect of genetic drift on the gene frequencies of a population A Chance alone can cause significant changes in gene frequencies of small populations B Genes enter a population through immigration thus changing gene frequencies C Exposure to mutagens increases the frequency of a particular trait in the population D Individuals with one allele reproduce more successfully than individuals with other alleles 4 Pleiotropy describes A the ability of a single gene to affect multiple phenotypic traits B when a heterozygote exhibits phenotypes for both its alleles C when one gene affects the expression of another gene D more than one gene affects a single phenotypic character 1 9 Which is are necessary for evolution of a trait by natural selection to take place 12 You cross a pair of fruit flies both of which have grey bodies and normal wings The table below shows the result of your cross Which statement best explains this outcome i The trait is heritable controlled by genes ii Differences among individuals lead to different numbers of successful offspring being produced iii Individuals change their behavior depending on the environment iv Every individual produces large numbers of offspring Trait Number of offspring Grey body normal wings 45 Black body shrivelled wings 5 Grey body shrivelled wings 15 Black body normal wings 15 A Crossing over did not occur during meiosis generating an unexpected ratio of traits B The body colour and wing shape traits are polygenic C Grey body and normal wings are incompletely dominant traits D The alleles for body colour and wing shape did not segregate during meiosis E The alleles for body colour and wing shape assort independently A ii only B i and ii C iii and iv D ii iii and iv E All of the above 10 Which is necessary for two populations to be considered separate species according to the biological species concept A They must be reproductively isolated from each other B They must accumulate a large number of different mutations C They must differ significantly in the sizes of their populations D Only a few of the offspring produced through matings between two populations survive E The two populations must be geographically separated from one another 13 In the pedigree shown above individuals with the solid symbols display a rare genetic trait caused by a recessive allele at an autosomal locus The probability that a child indicated by the question mark will have the disease is A 25 B 0 C 50 D 75 E 100 Concept Application Questions 11 Crossing over can be observed between which structures during prophase I A sister chromatids only B sister chromatids and non homologous chromosomes C non homologous different chromosomes D homologous and non homologous chromosomes E homologous chromosomes only 14 A man is brought to court in a paternity case He has blood type B The mother has blood group AB The child s blood type is A Which statement about the man is CORRECT A He might be the father B He is the father C He is not the father D there is not enough information to make a decision 2 15 In humans a widow s peak is caused by a dominant allele W and a continuous hairline is caused by a recessive allele w Short fingers are caused by a dominant allele S and long fingers are caused by a recessive allele s Suppose a woman with a continuous hairline and short fingers and a man with a widow s peak and long fingers have three children One child has a widow s peak and short fingers one has a widow s peak and long fingers and one has a continuous hairline and long fingers What are the genotypes of the parents A Female wwSS male WWss B Female wwSs male Wwss C Female wwSs male WWss D Female WwSs male WwSs E None of the above 18 In a population one of every five gametes carries a recessive allele Assuming Hardy Weinberg equilibrium what is the frequency of the homozygous recessive genotype in a population A 16 B 80 C 4 D 20 E 32 19 Which BEST explains why it is unlikely that humans will undergo speciation in the future A Random effects have become more important in large populations B Natural selection is no longer operating on humans C Migration among populations is high D The environment on Earth is being controlled and stabilized E There is not enough variation present in human populations 16 What is the probability of having an offspring showing