Study Guide for Biology Final
Final will cover topics from the 4th, 5th, and 6th weeks
Fourth 6 Weeks
Unit: Biotechnology 1. What are restriction enzymes and how are they used? Restriction enzymes cut DNA at specific sections of code. They are used to insert sequences of DNA at specific places. 2. Why is Gel Electrophoresis referred to as “DNA fingerprinting”? Gel electrophoresis results in a band of DNA fragments that looks like a barcode. Each person has a different pattern, so it can be used to identify people in paternity cases and the like just like a fingerprint. 3. Describe how gel electrophoresis separates DNA Gel Electrophoresis separates DNA fragments by size using electrical current across a gel plate. The longer fragments are heavy and make bands near the start of the gel, while smaller fragments move faster and travel farther. 4. What are plasmids and how are they used in genetic engineering? Plasmids are circular fragments of DNA that get picked up by bacteria. They copy independent of host DNA. Scientists use plasmids to insert genes into bacteria, plants, and other organisms. 5. Explain what is meant by a transgenic organism and give 2 examples of their role in genetic engineering. A transgenic organism has DNA from other organisms in their cells. One example is adding human protein-making genes to animals that produce our milk so that the milk we drink from them is more nutritious. Another example is adding animal genes to crops to make them heartier or resistant to diseases.
Unit: Mendelian Genetics 6. What are the phases of meiosis? Draw a simple diagram beginning with a diploid cell.

7. How is gametogenesis different in males and females? In male spermatogenesis, during anaphase II, 4 equal sperm are formed. In female oogenesis, during Anaphase II, 3 of the eggs formed donate their cytoplasm to the 4th, resulting in only one egg formed. 8. How do cross-over, independent assortment, and random fertilization lead to genetic diversity? Crossing over is where homologous chromosomes trade information. If the sister chromatids were different, then different combinations are made here. Independent assortment can match different combinations of chromosomes together so that the 4 haploid cells have a full set of chromosomes with different combinations of genes. Random fertilization further leads to genetic diversity because of random gene combinations from two different parents’ cells pairing together. 9. Define the following terms: a. Dominant allele – the expressed gene, denoted by a capital letter b. Recessive allele – the gene that is not expressed when the dominant is present, denoted by a lowercase letter c. Homozygous – both alleles are dominant or both alleles are recessive d. Heterozygous – contains one dominant allele and one recessive allele e. Genotype – the genetic makeup of an organism f. Phenotype – the physical characte3ristics of an organism g. Purebred – same as homozygous, alleles match h. Hybrid – same as heterozygous, alleles are different i. F1 generation – the first generation of offspring. F stands for “filial” j. Test cross – crossing an organism with unknown genotype with a homozygous recessive organism 10. Create a Punnett Square to determine the outcome of a cross between a White (pp) pea plant and a hybrid Purple (Pp) pea plant. Make sure to list the outcomes, phonotype and genotype ratios. | p | P | P | Pp | Pp | p | pp | pp | 50% Pp – Purple50% pp – white1:1 genotype and phenotype ratio | 11. Create a Punnett Square to determine the outcome of a cross between a heterozygous Tall Purple pea plant (TtPp) and another heterozygous Tall Purple pea plant (TtPp). Make sure to list the outcomes and phenotype ratios. | TP | Tp | tP | tp | TP | TTPP | TTPp | TtPP | TtPp | Tp | TTPp | TTpp | TtPp | Ttpp | tP | TtPP | TtPp | ttPP | ttPp | tp | TtPp | Ttpp |