Bio Flashcards
the formation of new and distinct species in the course of evolution
Speciation
Niche
what an individual does to obtain resources
Any change in the genetic sequence
Mutation
The exchange of DNA sequences between non-sister chromatids during meiosis I
Crossing-over
when individuals near the middle of the curve have higher fitness than individuals at the ends of the curve
Stabilizing selection
An individual having 2 identical alleles for a given trait
Homozygous
Different species fighting for the same resource
Competition
A trait thats controlled by 2 or more genes
Polygenic trait
The traits that are seen in an organism
Phenotype
A trait thats controlled by only one gene
Single-gene trait
The situation in which allele frequencies dont change
Genetic equilibrium
The number of times that an allele appears in a gene pool
Relative frequency
A change in the allele frequency due to migration of a small group of the population
Founder effect
Theory that states that allele frequencies in a population will remain constant unless factors cause those frequencies to change
Hardy-weinberger principle
Two or more species reproduce at different times
Temporal isolation
When members of two populations cannot interbreed and produce fertile offspring
Reproductive isolation
Requiring 2 of the same allele in order for a trait to be expressed in a homozygous individual
Recessive
When 2 populations are capable of interbreeding but have different mating strategies or rituals
Behavioural isolation
An individual having 2 different alleles for a given trait
Heterozygous
2 populations are seperated by geographic barriers
Geographical isolation
Random change in the allele frequency of different geneotypes in a small population
Genetic drift
A method of creating different genetic combinations during sexual reproduction
Gene shuffling
Indiviuduals at the ends of the curve have higher fitness than individuals in the middle of the curve
Disruptive selection
Random seperation of homologous pairs of chromosomes during meiosis I
Independent assortment
The genetic makeup of an individual
Genotype
when individuals at one end of the curve have higher fitness than individuals in the middle or lower ranges of the curve
Directional selection
Requiring only one allele for a trait to be expressed in a heterozygous individual
Dominant
All of the genes, including the different alleles, that are present in a population
Gene pool
What are the types of mutation to DNA sequences?
- Addition/insertion (extra nucleotides are added)
- Subtraction/deletion (nucleotides are omitted)
- Translation (switching the order of nucleotides
Bottleneck effect
Occurs when something happens, wiping out most of the population
