BIOL 1001 LSU Crousillac Final Chs 10- 12, 14 Questions and Answers

BIOL 1001 LSU Crousillac Final Chs 10- 12, 14 Questions and Answers 100% Pass **1. What is a gene?** - a. A segment of DNA that is only a few nucleotides long. - b. A unit of DNA that encodes the information necessary to produce proteins, cells, and entire organisms; can range from a few hundred to many thousands of nucleotides in length. - c. A type of RNA that carries genetic information. - d. A structure within the cell nucleus that contains DNA. **2. What is the locus of a gene?** - a. The entire length of a chromosome. - b. The specific location of a gene on a chromosome. - c. A type of nucleotide found in DNA. - d. A sequence of DNA that does not code for proteins. **3. What are autosomes?** - a. Chromosomes that determine the sex of an individual. - b. Non-sex chromosomes. - c. Chromosomes that are only found in gametes. - d. Chromosomes that carry mitochondrial DNA. **4. What are homologous chromosomes?** - a. Chromosomes that are identical in every way. - b. Chromosomes that carry the same kinds of genes for the same characteristics. - c. Chromosomes that are involved in crossing over during meiosis. - d. Chromosomes that are found only in males. **5. What are alleles?** - a. The same versions of a gene found at different loci. - b. Alternative versions of genes found at the same gene locus; formed by mutations. - c. The identical versions of a gene found at the same locus. - d. Random variations in the DNA sequence. **6. What does it mean to be homozygous at a gene locus?** - a. Homologous chromosomes carry different alleles at the gene locus. - b. Homologous chromosomes carry the same allele at the gene locus. - c. The gene locus is located on sex chromosomes. - d. The gene locus is mutated. **7. What does it mean to be heterozygous at a gene locus?** - a. Two homologous chromosomes carry the same allele at a given locus. - b. Two homologous chromosomes carry different alleles at a given locus; also called hybrid. - c. The alleles at the gene locus are dominant. - d. The alleles at the gene locus are recessive. **8. How does the Punnett Square method predict offspring genotypes and phenotypes?** - a. By analyzing the DNA sequences of the parents. - b. By observing the phenotypes of the offspring. - c. By combining gametes from both parents and filling in a 2x2 grid with the resulting genotypes. - d. By calculating the probability of mutation events. **9. Who is Gregor Mendel and what did he discover?** - a. A scientist who discovered the structure of DNA. - b. A biologist who discovered patterns of inheritance and many essential facts about genes, alleles, and their distribution during reproduction; used pea plants to observe these patterns. - c. A physicist who worked on quantum mechanics. - d. A chemist who discovered the periodic table. **10. Why did Mendel use pea plants for his experiments?** - a. Pea plants only have male reproductive structures. - b. Pea plants have both carpel (female) and stamen (male) reproductive structures and can naturally self-fertilize; Mendel could also cross-fertilize them. - c. Pea plants do not have visible traits. - d. Pea plants grow slowly and have a long generation time. **11. What was key to Mendel's success in his genetic studies?** - a. He used a complex design and studied multiple traits at a time. - b. He chose a simple design, studying one trait at a time and following several generations. - c. He focused on genetic mutations. - d. He used animals instead of plants. **12. What does "true breeding" mean in genetics?** - a. Heterozygous for a characteristic. - b. Homozygous for a characteristic. - c. Carrying different alleles at a gene locus. - d. Having no visible traits.