Genetics Chapter 1

the DNA found within all of our chromosomes
branch of biology that deals with heredity and variation (root of natural diversity). Study of genes.
segment of DNA that produces a functional product, usually a polypeptide. The blueprint for traits.
Large cellular molecules (4)
Nucleic acids, proteins, carbohydrates, and lipids. Form macromolecules composed of repeating units of smaller building blocks.
What is the largest MACROMOLECULE in living cells?
What gives organization to the structure of chromosomes? (2 things)
DNA + proteins
all the proteins that a cell makes at a given time
accelerate chemical reactions (a category of proteins)
2 Types of Enzymes
Catabolic: help breakdown molecules or macromolecules into smaller units. Important in the utilization of energy
Anabolic: help synthesis of mol. and macromol.
deoxyribonucleic acid, the genetic material
3 base sequences specifies one amino acid out of 20 possible choices
Functional protein is made of what?
one or more polypeptides. Functional proteins underlie cellular characteristics
Gene Expression
info in DNA is accessed to affect characteristics of cells and organisms in a stepwise process that includes transcription, translation, folding into a 3D structure, and the resulting production of proteins with specific structures and functions
Norm of reaction
the effects of environmental variation on an individual’s traits
Genes are passed from parent to offspring in discrete units
Vertical Transmission
passing of traits from parent to offspring
Horizontal Transmission
Occurs between two non-related organisms (mating bridge -> passing of DNA)
Organism that contains 2 copies of each chromosome, one from each parent (with exception of the sex chromosome). The two copies are HOMOLOGS of each other.
Somatic cells
all body cells except reproductive cells (contain 46 chromosomes)
reproductive cells, have only half the number of chromosomes (24) as body cells because aren’t diploid, they’re HAPLOID. Note: the union of gametes during fertilization restores the diploid number of chromosomes.
Biological Evolution
The genetic makeup of a population can change from one generation to the next
random genetic changes that occasionally occur within an individual’s genes and sometimes these changes lead to a modification of traits that promote reproductive success -> natural selection
Model organisms
organisms studied by many different researchers so they can compare results and determine scientific principles that apply broadly to other species (ex: E coli)
Transmission Genetics
examines the relationship between the transmission of genes from parent to offspring and the outcome of the offspring’s traits. Pedigree analysis and genetic cross used.
Genetic Cross
Used frequently in transmission genetics, involves the breeding of two selected individuals and the subsequent analysis of their offspring to try to understand how traits are passed from parents to offspring
Molecular Genetics
the molecular features of DNA and how these features underlie the expression of genes.
Loss-of-function mutation
used by molecular geneticists to analyze the effects of gene mutations that eliminate the function of a gene. The resulting gene is called a loss-of-function allele. By studying the effects of these mutations, the role of the functional, non-mutant gene is revealed
3 Sub-branches of Molecular Genetics
Cytogenetics (study of chromosomes and chromatin makeup and effects via a microscope)
Molecular (cutting apart and slicing DNA -> used of enzymes and biochemistry)
Genomic (computers advancing -> capacity to store and analyze massive amounts of data. Very discovery based)
Population Genetics
Study of genetic variation and its role in evolution. Explains how the variation in characteristics observed amount the members of a species is natural. Develop mathematical theories to explain the prevalence of certain alleles within a population of individuals.
Hypothesis Testing
Also called the scientific method. Series of steps to reach verifiable conclusions
Discovery based Testing
collection and analysis of data without a preconceived hypothesis
Neolithic revolution (New Stone age)
(10,000 years ago) Domestication of plants and animals began, this is where the study of genetics began and the cultivation of certain traits in a species to form an advantage. Evolution=natural, Domestication=artificial, the cultivation of traits that you want
Simple traits
Controlled by 1-2 genes (ex: baldness, color blindness)
Complex traits
affected by multiple genes, environment, and the interaction between genes and the environment (ex: cancer risk, intelligence)
Community + ecosystem
contrasting forms of a trait within a single species
morphological traits
traits affecting appearance
physiological traits
traits affecting ability to function
behavioral traits
traits affecting response to environment
different forms of a gene
defines an organism
gene pool
defines a population
defines a species
defines a communty