DNA segment: T A C T G T G G C A A A

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1 DNA Structure, Replication, Protein Synthesis & Name Period Genetics Study Guide Chapter 12 and 13 Structure of DNA and Protein Synthesis 1. What macromolecule is coded for by genes located on DNA? Provide three examples of proteins necessary in our bodies a. b. c. 2. What component of the DNA make up genes? 3. Where is DNA found in eukaryotic cells? 4. What is the goal of transcription? 5. Where does transcription take place in eukaryotic cells? 6. What RNA molecule copies the DNA code to serve as a template to make proteins during transcription)? 7. If a section of DNA has the following order of bases, what would the complementary DNA strand be? DNA segment: T A C T G T G G C A A A DNA 8. What is the goal of translation? Note: Translation happens in the cytoplasm of eukaryotic cells on the ribosomes. 9. What two RNA molecules are involved in translation 10. What is the job of each RNA molecule in translation? (rrna) and (trna) 11. What is a codon? 12. What is an anticodon? 13. Name the following amino acids using the amino acid codon chart on page 367. a. UUU c. ACC b. ACC d. CCC 14. What happens to cells (hopefully) if there is an error in the copying of the code during DNA replication? 15. Disorders caused when chromosomes fail to separate during meiosis are known as 16. Using the segment of DNA, transcribe the mrna and translate the trna into amino acids. Draw a line between the codons. Use the codon chart on page 367 in the book. T A C G T A G C T G A T A C T G T T A A G T G A mrna: trna: Amino Acids: 17. What are three main types of mutations? a. b. c. 18. What type of mutation causes Duchenne Muscular Dystrophy? 19. What type of mutation is sickle cell anemia? 20. What happens when there is a change in the nucleotide sequence to the protein? Explain. 21. Suppose a mutation occurred where the G in ( G A G) mutates to G A A? What amino acid does G A G code for? What amino acid does G A A code for? Would you expect this to be a detrimental mutation? This is called a point mutation and only involves one nucleotide base change. Explain.

2 22. What makes insertions and deletions frameshift mutations? Why is this type of mutation often more detrimental? Chapter What is a karyotype? Use the karyotype on page 392 to answer the following questions. 2. How many total autosomes are present in the karyotype? How many pairs? 3. How many sex- chromosomes are shown in the karyotype? What is the gender of this individual?. How do you know?. If it was XX the gender would be a. 4. Why the autosomes and sex chromosomes called homologous chromosomes? Use the definition of homologous in the glossary to help explain. 5. A child born with three #21 chromosomes is said to have trisomy 21, or. 6. The result likely happened when the chromosomes found in the egg failed to separate properly in meiosis. The failure of chromosomes to properly separate is called. Generally, nondisjunction occurs in eggs since the machinery involved in chromosome ages along with the female and gets less reliable as the eggs age. Remember a woman is born with all the germ cells necessary to make all the eggs in her lifetime. Punnett Squares are useful tools to find the probability of certain genetic combinations in offspring from the potential cross. The genotype of the parents determines the cross. During meiosis during gamete (egg and sperm) creation the chromosomes are randomly assorted between the. Complete dominance Many traits follow the pattern of simple dominance. In the case of complete dominance, one gene is dominant over another, recessive gene. 1. In cats, the spotting of the coat is due to a recessive gene, while a solid color coat is dominant. What type of offspring would a cross between two spotted animals produce? Show the genotypic and phenotypic ratios. Show the cross Genotypic Ratios: Phenotypic Ratios: 2. Brown eyes is dominant to blue eyes. Show the cross between two heterozygous parents to determine the chance of their children having blue eyes. 3. In Shmoos from planet Shmoovaria, pink fur is dominant over red fur. What are the chances of a homozygous red fur Shmoo and a heterozygous pink fur Shmoo having Shmoos with pink fur? Red fur? What are the genotypic ratios of the possible offspring? What are the phenotypic ratios of the possible offspring? Incomplete Dominance In the case of incomplete dominance, neither gene is fully dominant over the other, so they are expressed as a mix of the two. A capital letter represents each of the alleles/genes. Example W= White R= Red

3 4. In guinea pigs, neither yellow (Y) or (W) white color dominants. They blend, forming a cream color with the heterozygous mix. a cream-colored guinea pig with a yellow one. Give the genotypic and phenotypic ratios. 5. In four o clock plants, the flowers may be white or red in the purebred plant (homozygous). In the hybrid (heterozygous) plant, the flowers are pink. two pink flowers and give the genotypes, phenotypes and ratios. Let R = red and W= white. CROSS Ratios: Genotypic: Phenotypic: Codominance In cases of codominance, both alleles are dominant and both are expressed evenly. For example, a cross between a white flower (W) and a purple flower (P) would produce a purple and white spotted flower. 6. In some chickens, the gene for feather color is controlled by codominance. The allele for black is B and the allele for white is W. The heterozygous phenotype is known as erminette (black and white spotted). Show a cross between a Black and a White chicken (two erminette). CROSS a) What is the genotype for black chickens? b) What is the genotype for white chickens? c) What is the genotype for erminette chickens? 7. In shorthorn cattle, when a red bull (RR) breeds with a white cow (WW), all the offspring are roan a spotted, red and white or milky red color. What offspring are expected from mating a roan bull and a roan cow? Show the Punnett Square, phenotypes and genotypes. Genotypic Ratio: Phenotypic Ratio: Codominance and Multiple Alleles: Blood Type Human blood types are determined by genes that follow the CODOMINANCE pattern of inheritance with three possible alleles children can receive. There are two dominant alleles (A and B) and one recessive allele (O). Write the genotype for each person based on the description: a. Homozygous for the B allele b. Heterozygous for the A allele c. Type O d. Type A and had a type O parent e. Type AB 10. Draw a Punnett square showing all the possible blood types for the offspring produced by a type O mother and a Type AB father. CROSS 11. Pretend that Beyonce is homozygous for the type B allele, and Jay-Z is type O. What are all the possible blood types of their baby? CROSS

4 Part II: Pedigree Analysis A pedigree is used by genetic counselors to trace particular traits throughout a family history. This is useful to determine where genetic changes may have occurred, and also to see who passsed on certain genes. Part II: Pedigree Analysis 1. Which members of the family above are afflicted with Huntington s Disease? 2. There are no carriers for Huntington s Disease- you either have it or you don t. With this in mind, is Huntington s disease caused by a dominant or recessive trait? 3. How many children did individuals I-1 and I-2 have? 4. How many girls did II-1 and II-2 have? How many have Huntington s Disease? 6. The INCOMPLETE pedigree to the right shows the passing on of Hitchhiker s Thumb in a family. Fill in any carriers that you can identify as you work along. Is this trait dominant or recessive?

5 7. How do you know? 8. How are individuals III-1 and III-2 related? 9. Name 2 individuals that have hitchhiker s thumb. 10. Name 2 individuals that were carriers of hitchhiker s thumb. I 11. Is it possible for individual IV-2 to be a carrier? Why? 12. The pedigree shows the passing on of colorblindness. What sex can be carriers of colorblindness? 13. With this in mind, how do you think it is passed on in families? 14. Why does individual IV-1 have colorblindness? 15. Why do most of the daughters in generation II carry the colorblind gene? 16. How could a female inherit colorblindness? 17. Choose 8 individuals and fill in the gentoypes. 18. Would the female in generation 1 be a carrier? 19. Make a pedigree for the family described below: Brown eyes are dominant over eyes of another color (blue, green, hazel, violet, gre, etc.). Dale had brown eyes and marries Martha, who has green eyes. Their three children are Arthur (brown eyes), Violet (green eyes), and Lindsay (brown eyes). When they grow up, Arthur marries Estelle who has blue eyes. Violet marries Nathan who has green eyes and Lindsay marries Tom who has brown eyes. Estelle, Violet, and Lindsay are all expecting boy children. What are the possible outcomes for their children s eye colors? Draw the pedigree and explain the eye color possibilities for these boys.

6 20. At the age of 32, Tracy s doctor informed her she has Marfan syndrome. Neither of her parents have been diagnosed with Marfan syndrome; however, her maternal grandfather died of an aortic aneurysm at the age of 45. Tracy s husband Ben does not have Marfan Syndrome on his side of the family. Following, Tracy s diagnosis her brother, Luke and sister, Elyse go through genetic testing. Unfortunately, Luke tests positive. Elyse tests negative. Luke does not have any children. Elyse is married to Jimmy, and they have two girls. Tracy and Ben have one child that tests negative and another child on the way. What is the chance their unborn child will have Marfan? Do one of her parents likely have undiagnosed Marfan? Which one? Draw the Pedigree