Biology. Semester 2 Exam Review. Name: Block: Replication Transcription Translation Genetic Engineering. Mutation Codon Anticodon DNA Fingerprint

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1 Biology Semester 2 Exam Review Name: Block: Unit 1: DNA Define the following terms on a separate sheet of paper: Replication Transcription Translation Genetic Engineering Mutation Codon Anticodon DNA Fingerprint Explain how a DNA fingerprint can be used to solve crimes. Each person s DNA is different; a gel electrophoresis can be run to create a DNA fingerprint of DNA at the scene and of a suspect s DNA for comparison. Compare and contrast DNA & RNA. Which one is the blueprint of life? DNA Double stranded Sugar = Deoxyribose Thymine RNA Single stranded Sugar = Ribose Uracil Answer the following questions based on the DNA sequence: TACGCCTTG What will the complimentary DNA strand look like? ATGCGGAAC a. Transcribe the DNA into a strand of mrna. AUGCGGAAC b. Translate the mrna into a protein chain (you need your codon chart for this). Methionine-Arginine-Asparagine What are the base-pairing rules for a) DNA? T A C G b) RNA? C G T A A U

2 Describe the structure of DNA. Include all of the various parts that make up DNA. Phosphate backbone connected to sugar and a nitrogen base. Two strands of these nucleotides wound around each other. What are the three types of RNA? Where and how is each used? a. mrna messenger RNA: transfers information from the DNA strand to the ribosomes b. trna transfer RNA: carries amino acids to ribosomes for protein synthesis c. rrna ribosomal RNA: makes up part of the ribosomal subunits List and briefly describe the uses of genetic engineering. Forensics solving crimes Agriculture genetically modified plants and animals Fighting disease creating vaccines Describe the process of protein synthesis. DNA is transcribed into a strand of mrna which travels to the ribosomes. There, it is translated into a chain of amino acids. Does every mutation cause damage to an organism? Explain your answer. No, most mutations occur in introns and do not affect genes. The ones that do affect genes can often have no effect on the protein because there are multiple codons for each amino acid. Unit 2: Cell Division Define the following terms on a separate sheet of paper: Chromosome Diploid Haploid Trisomy Karyotype Mitosis Meiosis Cancer Crossing-over Autosome Sex-Chromosome All of the DNA in a cell is much larger than the cell itself. How does the DNA become more compact to fit inside the nucleus? It first wraps around itself (double helix) and then wraps around special proteins. It then coils, and super-coils until it is condensed down to fit in a cell.

3 What combinations of sex chromosomes produce males and females in humans? Male = XY Female = XX If a sperm cell contains 10 chromosomes, how many chromosomes will be in the organism s body cells? 20 (n=10, so 2n=20) List three characteristics of cancer cells. 1. Regulation of cell growth and division is lost 2. Cells do not respond normally to control mechanisms 3. Cells divide without passing through the G1 phase. Answer the questions at right using the diagram: 1. What does the diagram represent? Cell Cycle 2. What phase do cells spend the most time in? G1 of Interphase 3. What happens if the checkpoints stop working? Cell becomes a cancer cell Draw the four stages of mitosis and briefly explain each stage. See pages in textbook (

4 Draw the eight stages of meiosis and briefly explain each stage. See pages in textbook ( Compare and Contrast mitosis and meiosis. Be specific (think about the comparison worksheet you did during Unit 2). Mitosis Produces diploid cells Nucleus disappears Produces haploid cells Meiosis Equal division Produces somatic cells For growth and repair in the body Number of chromosomes doubles Crossing-over may occur For reproduction Reduction division Produces gametes

5 Unit 3: Genetics Define the following terms on a separate sheet of paper: Genotype Phenotype Heredity Genetics Homozygous Heterozygous Dominant Recessive Sex-linked Autosomal Pedigree Mutation Identify the pedigree as autosomal or sex-linked and dominant or recessive then give the most probable genotype of each of the individuals. Fill in the blanks: Mendel self-pollinated pea plants to create the _P_ generation. He then crossbred these plants to create the F1_ generation and finally, crossbred two of those to create the F2_ generation. Answer the following questions about sex-linked characteristics: 1. Where are sex-linked characters found? On the X chromosome 2. Who is more commonly affected by sex-linked traits, males or females? Males 3. List three sex-linked traits and disorders. Colorblindness, Hemophilia, fragile X syndrome

6 Perform the following crosses using a Punnett square then give the requested ratio: 1. Gg x Gg (genotypic) 2. TT x tt (phenotypic) G g T T G GG Gg t Tt Tt g Gg gg t Tt Tt 1:2:1 4:0 3. Yy x yy (phenotypic) 4. aa x aa (genotypic) Y y a a y Yy yy a aa aa y Yy yy a aa aa 2:2 0:0:1 What are the three human blood types? Give all possible genotypes for each phenotype. 1. Type A: I A I A, I A i 2. Type B: I B I B, I B i 3. Type AB: I A I B Sorry, I missed one in the question: Type O: ii Who is known as the father of genetics? Gregor Mendel Name at least three ways we can determine a person s risk of passing on a genetic disorder to their offspring. Pedigree analysis, prenatal testing, genetic counseling

7 Unit 4: Evolution Define the following terms on a separate sheet of paper: Natural selection Adaptation Gradualism Fossil Punctuated equilibrium Homologous structure Analogous structure Vestigial structure Population Competition Biological species Where did Chuck Darwin do most of his research? Galapagos Islands Explain natural selection. The most fit organisms survive and reproduce. The less fit organisms die off or produce way fewer offspring. Of the items listed below, circle any that could contribute to natural selection: phenotypic variation genetic variation renewable water supply environmental change limited living space global warming unlimited resources mutation food source There are three types of natural selection that can occur. Identify each of the graphs below based on the descriptions provided for each of the three. The dashed line shows a normal bell-shaped distribution. 1. Stabilizing Selection: the very light and the very dark moths are eliminated. 2. Disruptive Selection: favors both light and dark moths, does not favor anything in between. 3. Directional Selection: one phenotype is favored over the other.

8 If an organism is very well suited to its environment, it a. will reproduce at a greater rate. b. is always larger than organisms less-suited. c. requires less food and other resources. What main ideas did Darwin present in The Origin of Species by Means of Natural Selection? Modern organisms are produced by the process of evolution. Each new species descends from other species. Organisms undergo adaptation. Common descent all organisms descend from a common ancestor. List at least three examples of fossils. Old bones, traces of dead organisms, animals trapped in tree sap, shells, footprints, etc. Compare and contrast homologous structures and analogous structures. Give an example of each. Homologous: look different, serve different purposes, but have the SAME developmental pattern. Ex) forelimbs of vertebrates. Analogous: look different, have a different developmental pattern, but serve the same purpose. Ex) bird, bat, and butterfly wings. Name two vestigial structures in humans. Appendix, Tail bone Circle the following characteristics that a human embryo shows during development. Gill slits Fins a coat of fine fur a bony tail Explain speciation as it relates to Darwin s finches. What key adaptation in the finches is affected by the type of food available? Each group adapted to a specific food source; their beaks are specialized for those food sources.