Chapter 4: Genes and Their Evolution: Population Genetics Flashcards
Abnormal hemoglobin
Hemoglobin altered so that it is less efficient in binding to and carrying oxygen
Admixture
Exchange of genetic material between two or more populations
Anthropogenic
Refers to any effect caused by humans
Balanced polymorphism
Situation in which selection maintains two or more phenotypes for a specific gene in a population
Capillaries
Small blood vessels between the terminal ends of arteries and the veins
Deme
A local population of organisms that have similar genes, interbreed, and produce offspring
Directional selection
Selection favors one allele over others, causing allele frequency to shift in one direction
Disruptive selection
Selection for both extremes of the phenotypic distribution; may eventually lead to a speciation event
Endogamous
Breeding stays within the population
Equilibrium
Stability & balance
Exogamous
Breed outside of population
Fitness
Avg number of offspring produced by parents with a particular genotype compared to that of another
Founder effect
Accumulation of random genetic changes in a small population that has become isolated from the parent population due to input of only a few colonizers
Frameshift mutation
The change in a gene due to the insertion or deletion of one or more nitrogen bases, which causes the subsequent triplets to be rearranged and the codons to be read incorrectly during translation
Gene pool
All the genetic info in the breeding population
Glucose-6-phosphate dehydrogenase G6PD
An enzyme that aids in the proper functioning of red blood cells; it’s deficiency, a genetic condition, leads to hemolytic anemia
Hardy-Weinberg law of equilibrium
Mathematical model in population genetics that reflects the relationship between frequencies of alleles and of genotypes; it can be used to determine whether a population is undergoing evolutionary changes
Hemoglobinopathies
A group of related genetic blood diseases characterized by abnormal hemoglobin
Hemolytic anemias
Conditions of insufficient iron in the blood due to the destruction of red blood cells resulting from genetic blood diseases, toxins, or infectious pathogens
Huntington’s chorea
A rare genetic disease in which the CNS degenerates and the individual loses control over voluntary movements, with the symptoms often appearing between ages 30-50
Induced mutations
Mutations in the DNA due to toxic chemicals or radiation exposure
Klinefelter’s syndrome
Gives males an extra X chromosome (XXY) and reduces fertility
Macroevolution
Large-scale evolution over hundreds or thousands of years
Melanic
Darker due to high melanin concentrations
Microevolution
Small-scale evolution, such as changes in allele frequency, from one generation to the next
Mutagens
Substances that may induce genetic mutations
Nonsynonymous point mutations
A point mutation that creates a triplet coded to produce a different amino acid from that of the original triplet
Point mutations
Replacement of a single nitrogen base w another, which may affect the amino acid coded
Positive selection
Process in which advantageous genetic variants quickly increase in frequency in a population
Reproductive isolation
Any circumstance that prevents two populations from interbreeding
Sickle-cell anemia
Genetic blood disease in which the red blood cells become deformed and sickle-shaped, decreasing their ability to carry oxygen to tissues
Spontaneous mutations
Random changes in DNA that occurs during cell division
Stabilizing selection
Selection against the extremes of phenotypic distribution, decreasing the genetic diversity for this trait in the population
Synonymous point mutation
Neutral mutation, same amino acid is coded
Thalassemia
Genetic blood disease in which the hemoglobin is improperly synthesized, causing the red blood cells to have a much shorter life span
Transposable elements
Mobile pieces of DNA that can copy themselves into entirely new areas of the chromosomes
