Flashcards in Exam 1 Deck (41)
Mutations in ______ cells are more important
they are passed on to next generations.
change in one nucleotide
Substitution point mutations can be ________ (silent) or ________ (meaningful)
codon from this mutation specifies the same amino acid as the non-mutated codon. No protein change.
triplet sequence of nucleotides that specifies a particular amino acid
Non-synonymous (meaningful) point mutation-
missense, different amino acid, different protein.
Large sections of chromosomal mutations-
deletion, duplication, inversion, insertion, translocation.
Gene position may or may not be important in its __________
Trisomy 21 is due to _________. Leads to ___________
-nondisjunction, extra T21 chromosome
Fusion of a chromosome might be a significant effect in __________
Estimated number of protein coding genes in humans
Gross generalization: mutation rate per generation is:
10^-5 or 10^-6
mutation rate (_______) is too low to be main force in evolution. Between _____% of us carry a genetic mutation compared to our parents. Although mutation is too low to be main force of evolution, it is the only source of ___________
-.025 to .25
-new genes in a species.
Mutations increase genetic variability in a _________ and between __________
movement of alleles from one population to another due to mating between populations.
Gene flow inhibits speciation because ____________________
two populations blend their traits and they are now more similar and less likely to genetically diverge from each other.
random change in allele frequencies
The smaller the population, the more chance of significant ________
Two inferences we can make about genetic drift:
1. All populations evolve every generation by genetic drift
2. magnitude of evolution by genetic drift is greater in a smaller population than a larger population
The ultimate result of genetic drift is ___________, and all other alleles of the gene have been _______________
-fixation of an allele
-eliminated from the population
Bottleneck and Founder effects-
reduction in genetic variability by chance due to reduction in population size (bottleneck) or establishment of a new, founder population.
differences among individuals in reproductive success
The unit of natural selection is _________; the unit of evolution is ___________
-the individual organism
-the population (or species)
-Adaptation- result of _________
-Individuals are subject to natural selection, whereas populations (or species) _______
-Adaptation occurs only if differences among individuals in reproductive success have ____________
some inheritable basis.
Fundamental Theory of Natural Selection-
opportunity for natural selection is directly related to genetic variability in a population (or species)
There must be ____________________ for there to be natural selection.
genetic differences among individuals in a population (or species), and correspondingly phenotypic differences,
Natural selection “acts” directly on __________, and indirectly on ____________
Natural selection –
differential reproductive success among individuals in a population (or species).