Genetics Practice. 1. The diagram below shows the chromosomes from a cell after they were photographed under a microscope.

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1 Name: Date: 1. The diagram below shows the chromosomes from a cell after they were photographed under a microscope. Which of the following questions may best be answered by studying an organism s chromosomes?. What sex is the organism?. Is the organism endangered?. Where is the organism s ecosystem? D. How does the organism obtain its food? 2. In phenylketonuria (PKU), an enzyme that converts one amino acid into another does not work properly. Which of the following is the most likely cause of this genetic condition?. an error in the transcription of the gene for the enzyme. a mutation in the DN sequence that codes for the enzyme. an excess of the amino acids necessary to produce the enzyme D. a structural variation in the amino acid modified by the enzyme page 1

2 3. The diagram below represents DN fingerprints which are the result of gel electrophoresis done on several DN samples found at a crime scene. Which suspect is linked to the crime scene by this DN analysis?. Suspect. Suspect. Suspect D. Suspect D page 2

3 4. The picture below shows two mature plants. The two plants were cross-pollinated and each plant produced seeds. Which statement most likely describes a characteristic of the offspring that will grow from the seeds produced by each plant?. The offspring will grow taller than the parent plants.. The offspring will have healthier leaves than the parent plants.. The offspring will produce fewer flowers than the parent plants. D. The offspring will have light-colored flowers like the parent plants. 5. If Jessica has light eyes (bb) and both of her parents have dark eyes (b) which statement is true?. Jessica inherited both genes from her father.. Jessica inherited both genes from her mother.. Jessica inherited one recessive form of the gene from each parent. D. Jessica inherited one dominant form of the gene from each parent. page 3

4 6. The figure below shows a Punnet Square for an inherited trait. The arrow is pointing to a circled genotype in the square. What genotype does the circled dd represent?. the genotype in the mother s egg. the genotype that only the girls will inherit. the genotype that any of the children could inherit D. the genotype that exactly 1 4 of the children will inherit 7. In fruit flies, gray body color (G) is dominant over black body color (g). What kind of offspring would you expect from parents who are both heterozygous for body color (Gg Gg)? G g G g. 0% gray, 100% black. 25% gray, 75% black. 75% gray, 25% black D. 100% gray, 0% black page 4

5 8. In human beings, earlobes can be free or attached. Some people can roll their tongues while others cannot. The genotype and phenotype of two parents are shown below. Which trait cannot be transferred by this mother?. Free earlobes. ttached earlobes. annot roll tongue D. an roll tongue 9. Which trait will all of the offspring of the cross shown above exhibit?. an roll tongue. annot roll tongue. ttached earlobes D. Free earlobes 10. hildren would not be able to roll their tongues if they inherited a.. t allele from both parents. T allele from both parents. T allele from the mother and the t allele from the father D. t allele from the mother and the T from the father page 5

6 11. The figures below represent two chromosomes from an animal. Using the table below that describes the traits carried on hromosome #6, which trait can the animal inherit only from its mother? Genes on hromosome #6 H h b Trait long hair short hair black hair white hair. long hair. black hair. white hair D. short hair 12. The diagram below represents a cell. The letters in the diagram represent alleles for two different genetic traits. ccording to Mendel s law of independent assortment, which of the following shows all of the allele combinations expected in gametes produced by this cell?... D. 13. Which of the following terms applies to traits, such as human eye color, that are controlled by more than one gene?. codominant. polygenic. recessive D. sex-linked page 6

7 14. In a certain variety of chicken, some offspring have a feather pattern that is black-and-white checkered. hickens with this checkered feather pattern result from the cross of a black chicken with a white chicken. Which of the following types of inheritance is most likely responsible for the checkered feather pattern?. codominant. dominant. polygenic D. sex-linked 15. Two chromosome pairs from a diploid organism are shown below. ssuming meiosis and fertilization occur normally, which of the following pairs of alleles can an offspring receive from this parent?. and. and a. and f D. F and F 16. Hitchhiker s thumb (H) is dominant to no hitchhiker s thumb (h). woman who does not have hitchhiker s thumb marries a man who is heterozygous for hitchhiker s thumb. What is the probable genotypic ratio of their children?. 0% Hh : 100% hh. 50% Hh : 50% hh. 75% Hh : 25% hh D. 100% Hh : 0% hh page 7

8 17. The diagram below shows the pedigree of an individual with hemophilia, a sex-linked recessive condition. The diagram also shows how hemophilia is passed to offspring on an X chromosome. Hemophilia Pedigree Which statement explains why few females in the family have the condition?. Males have two X chromosomes.. Females have two X chromosomes.. Females have a Y chromosome. D. Males have a dominant Y chromosome. page 8

9 18. The diagram below represents a cross between two pea plants. In pea plants, the allele for round seeds (R) is dominant to the allele for oval seeds (r). In a cross between the two plants above, what percentage of the offspring will have round seeds?. 100%. 75%. 50% D. 25% 19. In pigeons, the allele for normal feathers (F) is dominant to the allele for frizzy feathers (f). If a purebred, normal-feathered bird (FF) is crossed with a frizzy-feathered bird (ff), how many different feather phenotypes are possible in the offspring? D Which of the following best describes the inheritance of a sex-linked trait?. a recessive allele carried by females that affects only males. a dominant allele carried by females that affects only males. an allele carried on the Y chromosome that can affect both males and females D. an allele carried on an X chromosome that can affect males or females page 9

10 21. If a corn plant has a genotype of Ttyy, what are the possible genetic combinations that could be present in a single grain of pollen from this plant?. Ty, ty. TY, ty. TY, Ty, ty D. Ty, ty, ty, TY 22. In certain breeds of dogs, deafness is due to a recessive allele (d) of a particular gene, and normal hearing is due to its dominant allele (D). What percentage of the offspring of a normal heterozygous (Dd) dog and a deaf dog (dd) would be expected to have normal hearing?. 0%. 25%. 50% D. 100% 23. Fur color in cats is controlled by an autosomal gene that can occur in the dominant form, (), or the recessive form, (b). The length of the cat s fur is controlled by another autosomal gene that occurs in the dominant form, (S), or the recessive form, (s). The table below shows the traits for these allele codes. The following genotypes were found in a male cat and a female cat. bss (male) bbss (female) Which one of the following choices is true of the phenotype of offspring from these parents?. ll offspring will have black fur.. ll offspring will have white fur.. ll offspring will have long-haired fur. D. ll offspring will have short-haired fur. 24. healthy individual is a carrier of a lethal allele but is unaffected by it. What is the probable genotype of this individual?. two dominant normal alleles. one recessive lethal allele and one dominant lethal allele. one recessive lethal allele and one dominant normal allele D. one dominant lethal allele and one recessive normal allele page 10

11 25. The pedigree below shows the occurrence of red-green colorblindness in four generations of a family. Use the information in the pedigree to answer the following question(s). Hemophilia, a blood disorder, is inherited in a similar way to red-green colorblindness. Therefore, hemophilia most often results when the affected gene is passed from. father to son. father to daughter. mother to son D. mother to daughter 26. In Pisum sativum, a pea plant, the allele for yellow seed color (Y) is dominant over the allele for green seed color (y). Two plants were crossed; three-fourths of the offspring plants had yellow seeds, and one-fourth of the offspring plants had green seeds. ased on these results, what were the genotypes of the parent plants?. Yy, yy. Yy, Yy. YY, yy D. YY, Yy page 11

12 27. In dogs, brown fur () is dominant to white fur (b). dog has a litter of 12 puppies of which 6 are brown and 6 are white. Which of these Punnett squares shows the cross that occurred?... D. 28. Individuals within a population of rabbits have different colors of fur as shown in the diagram below. The difference in the fur color of the individual rabbits is described as. speciation. variation. evolution D. succession 29. scientist crossed a tall pea plant with a short pea plant. ll of the four hundred offspring produced were tall pea plants. Which of these explains these results?. The allele for tall pea plants is dominant.. The offspring are homozygous dominant.. The allele for short pea plants is dominant. D. The offspring inherited a new mutation. page 12

13 30. In humans, the allele for dimples (D) is dominant. The allele for not having dimples (d) is recessive. woman (DD) and a man (Dd) have four children. Which of these is the predicted ratio of the children with dimples to the children without dimples?. 1 : 0. 1 : 1. 1 : 3 D. 3 : Which of these best describes the correct sequence in the expression of a trait?. trait gene enzyme. gene protein trait. protein gene trait D. gene trait DN 32. Which statement best describes a dominant gene?. It is the gene that produces mutations.. It is the gene that produces desirable traits.. It is the gene that masks a recessive gene. D. It is the gene that is masked by a recessive gene. 33. Red-green color blindness affects about 7.0% of the human male population. It affects approximately 0.4% of the human female population. These data suggest that red-green color blindness is a. dominant trait carried on the Y chromosome. dominant trait carried on the X chromosome. recessive trait carried on the Y chromosome D. recessive trait carried on the X chromosome page 13

14 34. Use the information and the pedigree below to answer the following question(s). In humans, the allele for having feet with normal arches is dominant ().The allele for flat feet is recessive (a). The pedigree below shows the occurrence of normal arches and flat feet in four generations of a family. In the pedigree, individuals are identified by the generation and individual numbers. For example, Individual 2 in Generation I is identified as I-2. PEDIGREE FOR INHERITNE OF NORML RHES Which of these individuals in the pedigree is a male with the genotype aa?. Individual I-1. Individual II-2. Individual III-2 D. Individual III Individuals III-6 and III-7 have two children and are expecting a third child. Their two children have flat feet. What is the chance that the third child will have normal arches?. 25%. 50%. 75% D. 100% page 14

15 cces format version c Educide Software Licensed for use by greg poruban Genetics Practice 04/08/ D 4. D D D D D D