Biol 341 Chap 1 genetics answers from 11 edition text book practice test questions and answers all done solution latest update

Chapter One A human genome is a vast store of information encoded in the sequence of building blocks of the molecule deoxyribonucleic acid (DNA). Genetic information affects our health and traits, and holds clues to how we are biologically related to one another. Summary 1.1 Introducing Genes and Genomes 1. Genetics investigates inherited traits and their variation. Genetic genealogy examines how people are related. Heredity concerns the transmission of traits. 2. Genes are the instructions to manufacture proteins, which determine inherited traits. Genes are composed of deoxyribonucleic acid (DNA). 3. A genome is a complete set of genetic information. A cell, the basic unit of life, contains two genomes. The exome is the part of the genome that encodes protein. Genomics compares and analyzes the functions of many genes. 4. Bioethics addresses issues and controversies that arise in applying medical technology and using genetic information. 1.2 Levels of Genetics and Genomics 5. The nitrogenous base sequences of genes encode proteins. The DNA bases are adenine (A), guanine (G), cytosine (C), and thymine (T). Ribonucleic acid (RNA) molecules have uracil (U) instead of thymine. DNA replication maintains the genetic information. Transcription, also called gene expression, copies DNA information into RNA, and translation uses the information in RNA to assemble amino acids into proteins. 6. A mutation is a change in a gene that can cause a disease if it alters the amino acid sequence of the specified protein. Mutation also refers to the process of change. 7. Variants of a gene are called alleles. They are inherited or arise by mutation. Alleles may differ slightly from one another, but encode the same protein. 8. Chromosomes consist of DNA and protein. When a cell is not dividing, the chromosomes are unwound and contained in a structure called the nucleus. A somatic cell in humans has 23 chromosome pairs. The 22 types of autosomes do not include genes that specify sex. The X and Y sex chromosomes bear genes that determine sex. Karyotypes are chromosome charts. 9. Single genes determine Mendelian traits. Complex traits reflect the influence of one or more genes and the environment. 10. Cells undergo differentiation by expressing subsets of genes. Stem cells divide to yield other stem cells and cells that differentiate. Tissues are groups of cells with a shared function. 14 11. The phenotype is the gene’s expression. An allele combination constitutes the genotype. Alleles may be dominant (exerting an effect in a single copy) or recessive (requiring two copies for expression). 12. Pedigrees are diagrams used to study traits in families. 13. Genetic populations are defined by their collections of alleles, termed the gene pool. Genome comparisons among species reveal evolutionary relationships. 1.3 Applications of Genetics and Genomics 14. DNA profiling compares DNA sequences of individuals to rule out identities, relationships, or ancestry, and can reveal if two individuals are related. 15. The microbiome consists of all of the microorganisms that are on or in a human body. 16. Precision medicine considers DNA information along with other types of information to learn about health and to develop new treatments for diseases. Pharmacogenetics considers gene variants to predict whether a specific drug will be effective or cause side effects in an individual. Genetically modified organisms are altered in ways that may not occur in nature. Genome editing adds, removes, or replaces specific genes. 1.4 A Global Perspective on Genomes 17. In metagenomics, DNA collected from specific habitats, including the human body, is sequenced to learn more about microbiomes. Key Terms • adenine (A) (ăd′en-ēn′) One of the four types of nitrogenous bases in DNA and RNA.