Key Terms
Alleles Haploid
Amino acid Homologs
Behavioral traits Hypothesis testing
Biological evolution Lipids
Carbohydrates Loss-of-function allele
Cellular level Loss-of-function mutation
Chromosomes Macromolecules
Deoxyribonucleic acid (DNA) Messenger RNA (mRNA)
Diploid Model organisms
Discovery-based science Molecular level
Environment Morphological traits
Enzymes Morphs
Evolution Natural selection
Gametes Norm of reaction
Gene Nucleic acids
Gene expression Nucleotides
Gene mutations Organismal level
Genetic approach Phenylketonuria (PKU)
Genetic code Physiological traits
Genetic cross Proteins
Genetic variation Population level
Genome Proteome
,Ribonucleic acid (RNA) Traits
Scientific method Transcription
Species Translated (translation)
Somatic Cells
,Chapter Outline
Introduction
1. The Human Genome Project began in 1990 as a project between the National Institutes
of Health (NIH) and the Department of Energy (DOE). The project was completed in
2003.
a. human genome contains approximately 3 billion nucleotide base pairs (Figure 1.1)
b. project is 99.99% accurate (1 error in 10,000 nucleotides)
2. Human Genome Project should enable scientists to:
a. determine the number of genes in humans
b. examine the relationship between genes and living cells
c. study the evolution of the species
d. understand developmental genetics
e. explore the relationship between genetic mutations and disease
f. develop new technologies for genetic studies
3. Modern genetic studies result in developments that affect our daily lives.
a. The development of new medicines such as Humulin. Humulin is human insulin
manufactured by E. coli bacteria.
b. DNA fingerprinting for forensic studies
c. Cloning of mammals, such as Dolly the sheep by Ian Wilmut and associates (1997)
(Figure 1.2)
d. production of transgenic organisms (Figure 1.3)
1.1 The Molecular Expression of Genes
Learning Outcomes:
1. Describe the biochemical composition of cells.
2. Explain how proteins are largely responsible for cell structure and function.
, 3. Outline how DNA stores the information to make proteins.
1. Genes represent the basic unit of heredity, while a trait represents the characteristics of
an organism. Genes provide the blueprint that determines an organism’s traits.
Living Cells Are Composed of Biochemicals
1. Small organic molecules provide energy for cellular functions as well as the building
blocks for larger molecules.
2. There are Four categories of biologically important organic molecules that are made of
repetitive subunits. These organic molecules are called macromolecules.
a. nucleic acids
b. proteins
c. carbohydrates
d. lipids
3. Larger cellular structures, such as chromosomes, are built from combinations of
macromolecules and smaller molecules (Figure 1.4).