1. Animal breeders use test crosses to determine whether an individual animal ________. 1.is fertile 2.is homozygous dominant or heterozygous 3.is homozygous recessive or heterozygous 4.is phenotypically dominant or recessive 5.was the product of segregation or independent assortment 123

2. Blood typing is often used to resolve questions of paternity; could a man with blood type A father a child with blood type B? 123 1.no, only males with type B or AB have children with type B blood 2.yes, if his genotype was I A I i and the mother had B or AB blood 3.yes, independent assortment recombines all possible blood- group genes during gamete formation 4.no, children always have the same blood type as their fathers 5.yes, blood type is the result of environmental influences, not inheritance

3. Assuming the species to be diploid, the notation Ab would be used to represent ________. 1.a gamete from a dihybrid cross 2.an individual from the F1 generation 3.a heterozygous parent 4.an individual displaying both dominant phenotypes 5.this notation would never be encountered 123

4. When tall peas are crossed with dwarf peas, the resulting seeds all grow into tall plants, indicating that ________. 1.tall plants survive better in the natural environment 2.tall is the dominant form for the alleles controlling height 3.plant height is strongly influenced by environmental factors 4.plant height in peas is a polygenic trait 5.pleiotropy can be observed in both plants and animals 123

5. The first three children of a couple, both heterozygous for cystic fibrosis, were healthy; what is the probability that a fourth child will have the disease? 1.100% 2.75% 3.50% 4.25% 5.it is impossible to predict 123

6. The 9:3:3:1 ratio reported by Mendel during dihybrid crosses suggested that ________. 1.dominant alleles are superior to recessive alleles and appear more frequently in offspring 2.the sorting of any pair of homologous chromosomes is independent of the sorting of any other pair 3.either homozygous genotype is preferable to the heterozygous phenotype 4.mutation rates are unusually high in pea plants 5.segregation applied only to monohybrid crosses 123

7. Which example illustrates pleiotropy? 1.human ear lobes may be attached or free 2.crosses between red and white snapdragons produce pink snapdragons 3.individuals homozygous for the cystic fibrosis allele suffer numerous physiological problems 4.humans have one of the four blood types within the ABO system 5.when tall, purple peas are crossed with short, white peas, some offspring may be tall and white 123

8. What conclusions can be made of a five-fingered child born to polydactylous parents, a dominant trait characterized by extra fingers? 1.a mutation reversed the allele to its normal state in either of the parent's gametes 2.polydactyly must not be a genetic condition 3.the parents were both heterozygous for the condition 4.the environmental factors favoring the development of polydactyly were absent for the child 5.polydactyly must result from an epistatic interaction 123

9. If an ABO blood typing reveals that you are homozygous recessive (I i I i ), your blood type ________. 1.could be either A or B 2.must be O 3.must be A 4.must be B 5.must be AB 123

10. Offspring of a cross between true-breeding lineages that inherit nonidentical alleles are called ________. 1.hybrids 2.recessives 3.mutants 4.codominants 5.recombinants 123

11. When crossing a homozygous-dominant parent with a homozygous-recessive parent, the offspring will ________. 1.produce a 1:2:1 genotype ratio and a 3:1 phenotype ratio 2.produce a 1:1 genotype ratio and a 1:1 phenotype ratio 3.produce a 3:1 genotype ratio and a 3:1 phenotype ratio 4.produce a 3:1 genotype ratio and a 1:2:1 phenotype ratio 5.all be the same, both genotypically and phenotypically 123

12. Several molecular forms of the same gene may exist; collectively these forms are termed ________. 1.alleles 2.homologous genes 3.loci 4.mutations 5.heterogeneous genes 123

13. In a genetics experiment, the offspring produced when parents are crossed are called ________. 1.the F1 generation 2.the F2 generation 3.the P2 generation 4.the heterozygotes 5.none of the choices is correct 123

14. With the exception of identical twins, brothers and sisters of the same parents are notably different because ________. 123 1.independent assortment recombines genetic material in new ways during gamete formation 2.crossing over recombines genetic material in new ways during gamete formation 3.each pair of chromosomes [MKC1] segregates during gamete formation 4.many features require several pairs of genes that may not be closely linked 5.all of the choices are correct

15. Two genes are closely linked when ________. 1.the combination of features increases the fitness above that of either trait separately 2.the distance between their loci is small 3.they are located on homologous chromosomes 4.their recombination frequencies are high 5.all of the choices are correct 123

16. The genes for ABO blood typing are I A, I B, and I i ; the superscripts indicate that ________. 1.three separate loci are associated with this trait 2.the genes are incompletely dominant 3.the genes for blood typing form a linkage group 4.the locus has multiple alleles 5.ABO blood typing results from epistatic interactions 123

17. The coat color in Labrador retrievers is the result of epistasis, an interaction ________. 1.between the skin temperature and the activity of the enzymes producing fur pigmentation 2.between an allosteric inhibitor and the enzymes responsible for fur coloration 3.when an individual allele has more than one effect on the phenotype 4.between the dominant and recessive alleles 5.where two pairs of genes interact to produce the phenotype 123

18. If a plant that breeds true for the dominant version of a trait is crossed with one that breeds true for the recessive version of that trait, they will produce ________. 1.homozygous and heterozygous offspring in equal proportions 2.offspring that are homozygous for the dominant version of the trait 3.offspring that are homozygous for the recessive version of that trait 4.offspring that are heterozygous for the trait 5.a random and unpredictable mix of both phenotypes 123

19. When yarrow cuttings are planted at different elevations, the plants show different forms because: 1.in yarrow, phenotype is influenced by the environment 2.a plant's genotype can change during its lifetime 3.the cuttings were not genetically identical 4.soil variations exist at different elevations 5.higher altitudes experience more intense radiation and thus higher rates of mutation 123

20. Geneticists are using marker-assisted selection in their efforts to breed roses; in this technique, ________. 1.DNA probes are used to determine if an offspring plant has inherited a specific gene 2.the mature flower of an offspring plant fluoresces when illuminated with ultraviolet light 3.rose pollen is exposed to radiation before pollination 4.the seeds from experimental crosses are planted, grown to maturity, and then evaluated for markers such as fragrance 5.stamens are cut so that self- pollination is not possible 123