Chapter 13 Flashcards
Inbreeding
Breeding closely related individuals
- offspring are homozygous for the traits desired
- harmful recessive traits can also appear
- horses and dogs examples of pure breeds
Selective Breeding
Humans select plants and animals to breed together
- takes several generations
- increase the frequency of desires alleles
Hybrids
Offspring formed when parents have different traits
- cross disease resistant plant with one the produces large fruit
- examples of hybrids: wheat, rice, corn and roses
Test cross
If you want to determine the genotype of an individual
-see if a plant is TT or Tt by crossing it with a tt plant
Genetic engineering
Cut DNA from the host organism and insert it into another organism
- quicker than selective breeding
- more specific
Transgenic organism
Organism that contains DNA from a different genus (species)
-ex. Tobacco given a gene from a firefly to make it glow
Recombinant DNA
Made by connecting and recombining fragments from different sources
Restriction enzymes
Cut DNA in specific places
- come from bacteria
- usually look for palindromes
- sticky ends are better
Palindromes
DNA that reads the same from front to back
Vectors
Anything that carries or transmits something (ex. Disease or DNA)
-can be biological or mechanical
Biological vectors
Viruses and plasmids
Mechanical vectors
Micropipette or gene gun
Cloning
Clones are identical copies
- same genetic info as parent
- ex. Dolly the sheep
Polymerase chain reaction (PCR)
PCR- used to replicate DNA outside a living organism
Three step PCR cycle
Heating, cooling and replication
-brings about a chain reaction that produces an exponentially growing population of identical DNA molecules
