Linked Genes
Two traits appear together if on same chromosome
Crossing over
leads to recombination; the closer the genes are the more linked they are
Mapping chromosomes
further apart on chromosomes the more likely to change during crossing over
Deletion
removes a chromosomal segment
Duplication
repeats a segment
Inversion
reverses a segment within a chromosome
Transiocation
moves a segment from one chromosome to a nonhomologous chromosome
DNA Replication
separate stands; fill in new strands by complement nucleotides of old strands; can proofread and repair
Transcription
make RNA copy of DNA
Translation
chaning RNA to protein
Ways to regulate activity in Eukaryotic cells
Protein processing- not activated if not processed; Protein degradation- less reaction catalyzing if faster degradation; Protein on/off switches- activators/repressors can bind; Change translation- can block initiation
Population
all organisms of one kind in one area
Gene pool
all possible alleles in a population
Allele frequency
for a given gene, what proportion for a single allele
Hardy-Weinberg principle
allele and genotype frequency in a population will remain constant generation to generation
5 conditions for Hardy principle
no mutations, no natural selection, no gene flow, mating must be random, population must be large
Evolution
any change in the genetic makeup of a group over time
Evolution needs to have
change, genetic, group, time
Genetic drift
change due to random chance
Founder effect
new population has different ratios than source
Bottleneck effect
change after drastic decline
Gene Flow
allele movement between populations
Adaptation
modifications fit to way of life
Natural selection
inherited traits to survive and reproduce
Relative fitness
contribution to the gene pool of next generation relative to other individuals in the population
Directional selection graph
shifts in one direction
Disruptive selection graph
turns into two humps that favors the ends
Stabilizing selection graph
range gets thinner
Heterozygote advantage
both types of homozgote have lower fitness; preserves genetic variation