Topic 6: Genetics. 1. The transfer of genes from parents to their offspring is known as

Transcription

1 1. The transfer of genes from parents to their offspring is known as 5. The diagram below represents a reproductive process that takes place in humans. (1) differentiation (2) heredity (3) immunity (4) evolution 2. The diagram below shows a diploid cell with two homologous pairs of chromosomes. Which statement does not correctly describe this process? (1) The normal species chromosome number is restored. (2) Males and females each contribute DNA to the offspring. (3) The zygote will develop to become identical to the dominant parent. Due to independent assortment what possible combinations of alleles could be found in gametes produced from this cell by meiosis? (1) Aa, Bb, AA, and bb (2) AaBb and ABab (3) AB and Ab, only (4) AB, Ab, ab, and ab 3. The sorting and recombination of genes during sexual reproduction is important to evolution because these processes (1) decrease variation and help maintain a stable population (2) increase variation that enables species to adapt to change (3) decrease the chances of producing offspring that are adapted to the environment (4) increase the ability of all the offspring to adapt to the environment 4. Which genotype illustrates codominance of alleles that control blood type in humans? (1) ii (2) I A i (3) I B I B (4) I A I B (4) The sex of the zygote is determined by DNA in the gametes. 6. In watermelon plants the allele for solid green fruit (G) is dominant over the allele for striped fruit (g). Pollen from a flower of a homozygous green watermelon plant is used to pollinate a flower from a heterozygous green watermelon plant. What percent of the offspring of this cross will bear striped watermelons? (1) 25% (2) 50% (3) 100% (4) 0% 7. In minks, the gene for brown fur (B) is dominant over the gene for silver fur (b). Which set of genotypes represents a cross that could produce offspring with silver fur from parents that both have brown fur? (1) BB Bb (2) Bb bb (3) BB bb (4) Bb Bb 8. The genes for red hair and freckles are usually inherited together because these genes are (1) homologous (2) sorted independently (3) linked (4) hybrid traits Page 1

2 9. The gene for tallness (T) is dominant over the gene for shortness (t) in pea plants. A homozygous dominant pea plant is crossed with a heterozygous pea plant, and 200 seeds are produced. Approximately how many of these seeds can be expected to produce plants that are homozygous dominant? 13. Base your answer on the graph below and on your knowledge of biology. (1) 100 (2) 0 (3) 50 (4) A geneticist wishes to determine if a red rose of a certain variety is homozygous for the color red. If red is dominant over white, the red rose should be cross-pollinated with roses of the same variety that are (1) homozygous red (2) homozygous white (3) heterozygous red (4) heterozygous pink 11.A cross between two plants that have pink flowers produced plants that have red, pink, or white flowers. Which is the most likely explanation for these results? (1) Intermediate inheritance involved alleles that were not clearly dominant or recessive. (2) Mutations occurred during gametogenesis. (3) Crossing-over of white and red alleles occurred during meiosis. (4) Nondisjunction of homologous pairs of chromosomes resulted in the production of abnormal offspring. 12. A boy inherits genes for tallness, but his growth is limited as a result of poor nutrition. This is an example of (1) an inherited disorder (2) environmental influence on gene expression (3) expression of a hidden trait (4) a characteristic controlled by more than one pair of genes If the environment were to change dramatically or a new plant disease were to break out, which plant type would most likely survive? (1) wild wheat (2) domestic wheat (3) wild corn (4) domestic corn 14. Several goldfish were kept in a small aquarium for several years. The fish grew to be approximately 6 centimeters long in the first year, and after that, growth in length stopped. These fish were later transferred to a large pond. In the pond, the goldfish grew much larger, reaching lengths of around 25 centimeters. Which statement provides the best explanation for the increased growth of the fish in the pond? (1) Chemicals present in the pond increased the amount of DNA in the fish, causing the growth increase. (2) The expression of genetic information in the fish was influenced by their surroundings. (3) The fish expressed and passed on only those characteristics that enabled them to survive in the new environment. (4) The size of the fish depended only on their food supply and not on their DNA. Page 2

3 15. The diagram below represents the organization of genetic information within a cell nucleus. 17. The diagram below represents the banding pattern for human chromosome 11, with some of the bands labeled. The circle labeled Z most likely represents (1) amino acids (2) chromosomes (3) vacuoles (4) molecular bases 16. Which diagram represents a pair of homologous chromosomes? The bands represent (1) proteins (2) genes (3) starches (4) enzymes 18. The diagram below shows a process that can occur during meiosis. (1) The most likely result of this process is (2) (3) (4) (1) a new combination of inheritable traits that can appear in the offspring (2) an inability to pass either of these chromosomes on to offspring (3) a loss of genetic information that will produce a genetic disorder in the offspring (4) an increase in the chromosome number of the organism in which this process occurs Page 3

4 19. Molecule 1 represents a segment of hereditary information, and molecule 2 represents the portion of a molecule that is determined by information from molecule As a result of sexual reproduction, an organism can pass a gene mutation to its offspring if the mutation occurs in (1) a body cell (2) a sex cell (3) liver tissue (4) white blood cells 22. Mutations that occur in skin or lung cells have little effect on the evolution of a species because mutations in these cells What will most likely happen if there is a change in the first three subunits on the upper strand of molecule 1? (1) The remaining subunits in molecule 1 will also change. (2) A portion of molecule 2 may be different. (1) usually lead to the death of the organism (2) cannot be passed on to offspring (3) are usually beneficial to the organism (4) lead to more serious mutations in offspring (3) Molecule 1 will split apart, triggering an immune response. (4) Molecule 2 may form two strands rather than one. 20. Which situation would most directly affect future generations naturally produced by a maple tree? (1) Ultraviolet radiation changes the DNA sequence within some leaves of the tree. (2) Ultraviolet radiation changes the DNA sequence within the gametes of some flowers of the tree. (3) An increase in temperature reduces the number of cell divisions in the roots. (4) Rapidly growing cells just under the bark are exposed to radiation, causing changes in genetic material. Page 4

5 Base your answers to questions 23 through 27 on the diagram below of the chromosomes from a human cell and on your knowledge of biology. 27. This chromosomal arrangement indicates that the individual has (1) phenylketonuria (2) Down's syndrome (3) sickle-cell anemia (4) Tay-Sachs disease Base your answers to questions 28 through 30 on the pedigree chart below which shows a history of blood types. 23. Which procedure can be performed during fetal development to detect the chromosomal disorder illustrated by the diagram? (1) genetic counseling (2) amniocentesis (3) urine analysis (4) cloning 24. The diagram represents a (1) deletion (2) synapsis (3) karyotype (4) disjunction 25. The chromosomes are arranged to show (1) homologous pairs (2) tetrads (3) independent assortment (4) nucleotides 26. The individual from whom these chromosomes were taken is a 28. The blood types of the individuals represented in the chart by 7 and 8 could be (1) A or B, only (2) AB, only (3) A, B, or AB, only (4) A, B, AB, or O 29. The genotype of the individual represented in the chart by 5 is (1) I a I a (2) I a i (3) ii (4) I a I b 30. Which individuals represented by the chart must be homozygous for blood type? (1) 1 and 2 (2) 2 and 3 (3) 3 and 4 (4) 1 and 4 (1) male (2) female (3) hermaphrodite (4) polyploid Page 5

6 31. A mother pregnant with her fourth child remarked, "This one just has to be a boy. It is almost certain, since my other three children are girls." Which statement best indicates the accuracy of the mother's comment? 33. In the diagram below, strands I and II represent portions of a DNA molecule. (1) The mother is wrong because the chance of having a boy is always 50%. (2) The mother is wrong because there is only a 25% chance that the child will be a boy. (3) The mother is right because the genes of the father are dominant over those of the mother. (4) The mother is right because a child usually inherits both sex chromosomes from the mother. Strand II would normally include (1) AGC (2) TCG (3) TAC (4) GAT 32. Three structures are represented in the diagram below. What is the relationship between these three structures? (1) DNA is made up of proteins that are synthesized in the cell. (2) Protein is composed of DNA that is stored in the cell. (3) DNA controls the production of protein in the cell. (4) The cell is composed only of DNA and protein. Page 6

7 Base your answers to questions 34 through 36 on the diagram below and on your knowledge of biology. The diagram represents molecules involved in protein synthesis. 37. A scientist claimed that he had cloned a guinea pig to produce two offspring, a male and a female. The claim is not valid because (1) guinea pigs can reproduce both sexually and asexually (2) the two offspring are not identical copies of the original guinea pig (3) each of the offspring had half the genetic information of the original guinea pig (4) none of the genetic information came from the original guinea pig 34. In eukaryotic cells, molecule 1 is found in the (1) centriole (2) nucleus (3) cell wall (4) lysosome 35. Where does the production of molecule 3 take place? (1) in the vacuole (2) on the plasma membrane (3) in the lysosome (4) at ribosomes 36. The building blocks of molecule 3 are known as (1) RNA molecules (2) DNA molecules (3) fatty acids (4) amino acids 38. In several species of birds, the males show off their bright colors and long feathers. The dull-colored females usually pick the brightest colored males for mates. Male offspring inherit their father s bright colors and long feathers. Compared to earlier generations, future generations of these birds will be expected to have a greater proportion of (1) bright-colored females (2) dull-colored females (3) dull-colored males (4) bright-colored males 39. According to the Hardy-Weinberg principle, the gene pool of a population will remain stable if (1) no mutations occur (2) the population is small (3) individuals migrate into and out of the population (4) nonrandom mating occurs by artificial selection Page 7

8 Base your answers to questions 40 and 41 on the pedigree chart below. The pedigree chart represents the inheritance of color blindness through three generations. 40. Which statement about the genotype of Linda and Donna regarding color blindness is correct? (1) Both carry one recessive allele. (2) Linda is a carrier, and Donna is homozygous dominant. (3) Both are homozygous recessive. (4) Linda is homozygous dominant, and Donna is a carrier. 41. Where is the allele for color blindness carried? (1) on the Y-chromosome, only (2) on the X-chromosome, only (3) on both the X- and Y-chromosomes (4) on neither the X- nor the Y-chromosome Page 8

9 42. The diagram below represents a process that occurs during normal human development. Which statement is correct regarding the cells and DNA? (1) All the cells have identical DNA. (2) The DNA of the fertilized egg differs from the DNA of all the other cells. (3) The DNA of the fertilized egg differs from some, but not all, of the other cells. (4) Only the fertilized egg contains DNA. Base your answers to questions 43 through 45 on the diagram below, which represents some biochemical reactions involved in a cellular process. 43. The molecule coded directly from DNA is represented by number (1) 1 (2) 2 (3) 3 (4) What is an example of a molecule produced by this type of process? (1) glucose (2) glycogen (3) a fatty acid (4) a protein Page 9

10 45. What is the bond labeled 5 known as? (1) a peptide bond (2) a hydrogen bond (3) an ionic bond (4) a carboxyl bond 46. Modern dogs are direct descendants of the gray wolf. They first appeared about 130,000 years ago. Today, there are about 150 different breeds of domestic dog, a few of which are shown below. The great variety of modern dogs can best be explained by (1) selective breeding of dogs over many years (2) the cloning of domestic dogs (3) genetic alterations in gray wolves alive today (4) natural selection favoring wolves over dogs Page 10

11 Base your answers to questions 47 and 48 on the diagram below and on your knowledge of biology. 47. In the procedure indicated by letter A, DNA segments from humans and bacteria are joined by the action of (1) starch molecules (2) simple sugars (3) enzymes (4) hormone 48. Which process is indicated by letter B? (1) natural selection (2) mitosis (3) sexual reproduction (4) gene deletion Page 11

12 49. The graph below shows the changes in the number of individuals in a population who have a specific trait Topic 6: Genetics Which statement concerning this trait is a valid inference? (1) As time passed, an increasing number of individuals with this trait survived and reproduced. (2) Individuals can acquire new survival characteristics over time and pass them on to their offspring. (3) The longer a species is in an environment, the less likely it is that mutations will occur within the species. (4) The number of traits a species possesses has a direct relationship to the amount of time the species will exist. Page 12

13 Answer Key Topic 6-Genetics Page 13