genetics

• homologous chromosomes


  When the diploid number of chromosomes (2n) is reconstituted in a fertilized ovum, one chromosome in each pair came from the mother, and the other came from the father 
• alleles


  different forms of homologous genes
• dominant alleles


  gene always expressed, even if heterozygous
• recessive alleles


  two copies of gene needed to be expressed, must be homozygous
• incomplete dominance


  heterozygous is an intermediate phenotype
• codominance


  both phenotypes equally expressed
• multiallelic inheritance

  more than 2 alleles involved
• polygenic inheritance


  multiple genes involved
• homozygous


  both alleles identical
• Heterozygous


  alleles different
• genotype


  complete set of genes and alleles
• phenotype


  observed physical and functional traits (depends on interaction of alleles and environment)
• genetics involve two basic things

  determining where the alleles for a genotype come from, and then determining the phenotype based on that genotype
• T/F: type AB blood is a phenotype

  true
• if 'red stripes' is dominant , and you have a homozygous red mom and a homozygous blue dad, the children would be

  red stripes
• if 'stripe color' is controlled by a single gene, all individuals are red or blue stripes, and a pair of blue striped parents have a red striped child, then 'red stripes' is

  recessive
• phenotype for many traits is going to depend on

  both alleles, multiple genes and environment
• if you are heterozygous for two different genes AaBb, what combination of alleles could you pass on


  AB, Ab, aB, ab
• blood types: if mom is A, son is B, daughter is O - what is dads blood type?

  B
• gene flow


  this causes of evolution in a population comes from other population - the mixing of populations
• natural selection selects alleles that on average gives the most

  offsprings
• which two causes of evolution are random in their direction

  mutation and genetic drift
• if the male genotype is XY and the female genotype is XX then males are ___ for the sex trait and females are ___

  heterozygous; homozygous
• if a woman is colorblind (x-linked recessive) and her husband is not then ___ of their daughters will be colorblind and ___ of their sons will be colorblind

  none; all
• if the alleles for 'red stripes' is incompletely dominant, and one parent has homozygous red and the other has homozygous blue then the children will have

  purple stripes
• T/F: freckles is a phenotype

  true
• meiosis results in

  4 haploid cells
• polygenic inheritance

  If two or more genes have combined effects on the phenotype, ex: skin color
• ABO blood group gene in humans is an example for a gene with

  multiple alleles
• x linked inheritance

  characteristics: mostly males with disease (recessive, they only have one X copy), passed to sons by mother, father cannot pass the gene