AP Bio

  1. Gene
    A segment of DNA that codes for the basic unit of heredity; transmitted from one generation ot the next.
  2. Locus
    The location of a gene on a chromosome
  3. Gamete
    reproductive cells
  4. Mandelians 4 Principles
    • 1. alternative versions of genes cause variations in inherited characteristics in offspring.
    • 2. every organism inherits one one allele from each parent.
    • 3 if 2 alleles are different, dominant allele will be fully expressed in offspring, recessive allele will have no noticeable effect in offspring
    • 4. the 2 alleles for each character separate during gamete production.
  5. Test cross
    • - determines if an individual showing dominant trait is homozygous or heterozygous.
    • - homozygous dominant = dominant phenotypes
    • - heterozygous = ratio of dominant to recessive
  6. Monohybrid Cross
    cross involving the study of one character (ex. flower color)
  7. Dihybrid cross
    Cross involving the study of multiple characters.
  8. Incomplete Dominance
    F1 hybrids have the apparance between 2 parents. (ex. red and white flowers make pink flowers)
  9. Multiple Alleles
    Gene has more then 2 alleles. (ex. human blood type)
  10. Pleiotrophy
    a single gene gives off more then one effect
  11. Epistasis
    gene at one locus alters gene at another locus.
  12. Polygenic inheritance
    two or more genes have one effect on a single character.
  13. Sex linked inheritance
    inheritance from the sex genes x and y.
  14. X inactivation
    regulates gene dosage in females.
  15. Nondisjunction
    members of a pair of homologous chromosomes don't separte right during mieosis 1; result is one gamete recieve 2 copies of chromosome while the other recieves none. offspring will have incorrect chromosome number.
  16. Stomatic cells
    Cells with 46 chromosomes
  17. Homologous chromosomes
    • -4 DNA strands
    • -2 chromosomes
    • -both chromosomes of each pair carry the same genes that control inherited characteristics
  18. Hapliod cells
    contain half the # of chromosomes; sperm and egg.
  19. Dipliod
    46 chromosomes
  20. Zygote
    Fertilized egg
  21. Interphase
    Cell duplicated its DNA; each chromosome has 2 identical sister chromatids.
  22. Prophase 1
    • -chromosomes condense
    • -2 sister chromotids attach at centromere
    • -synapsis occurs (joining of homologous chromosomes) forming tetrads (new structure)
    • -crossover occurs (dna from one homologue is cut and exchanged for another)
    • -nuclear envelope desinigrates
    • -spindle attaches to homologues
  23. Metaphase 1
    homologues line up at metaphase plate
  24. anaphase 1
    chromosomes move toward opposite ends of the cell.
  25. telophase 1 and cytokenesis
    • -move until they reach opposite poles
    • -hapliod set of chromosomes
    • -2 sister chromotids
  26. Prophase 2
    • -spindle apparatus
    • -sister chromotids move toward plate
  27. metaphase 2
    • -chromosomes at metaphase plate
    • -prepare to move toward opposite poles
  28. anaphase 2
    • -centromeres of sister chromotids separate
    • -move toward opposite cells
  29. Telophase and cytokenesis
    • -chromosomes move all the way to opposite ends
    • -nuclei reappear
    • - cytokenesis occurs
    • -4 daughter cells have hapliod number of chromosomes
  30. events that occur in mieosis that don't occur in mitosis
    • 1. synapsis and crossover
    • 2. metaphase 1- homologues are at plate rather then individual chromosomes
    • 3. anaphase 1- sister chromotids of each duplicated chromosome stay attached
  31. DNA Structure
    • -double helix
    • -backbone- sugar-diphosphate
    • -nitrogous bases (Adanine, guanine, cytocine, and thymine)
    • -Backbones are antiparallel- right = 5-3 left = 3-5
  32. 6 major points of DNA replication
    • 1. begins at origin of replication
    • 2. protiens bind to origin of replication and separate strands (5-3 direction)
    • 3. DNA polyinerase catalyse elongation of new dna at replication fork
    • 4. poly. adds new nucleotides to to chain
    • 5. replication occurs continuously on 5-3 strand (leading strand)
    • 6. the 3-5 is copied in a series of segments called Okazaki fragments and sealed by DNA Ligase
  33. Transcription
    • produces rna using DNA template; takes place in nucleus.
    • three stages:
    • 1. initiation- Poly2 transcribes mRNA; binds to promotor using protiens (transcription factors)
    • 2. elongation- rna poly moves along dna untwisting and adding new nucleotides to the 3 end.
    • 3 Termination- poly detaches; rna transcript is released
  34. mRNA
    Carries genetic message of DNA to protien making ribosomes.
  35. Translation
    production of a peptide chain using mRNA; occurs in ribosomes. Instructions for the peptide chain written in triplet code. (series of three nucleotide groups.) (codons)
  36. tRNA
    transfers amino acids to ribosome;
  37. 3 ribosome binding sites
    • p site- hold trna that carries peptide chain
    • a site- holds trna that carreis amino acid thats added to next chain
    • e site- exit
  38. three stages of translation
    • 1. initiation- first codon is always AUG
    • 2. elogation
    • 3. termination
  39. Three parts of Operon
    • 1. operator- controls access of rna poly.
    • 2. promotor- rna poly attaches
    • 3. genes of operon
  40. Repressible operon
    • -The operon (gene) is normally on but can be turned off.
    • -anabolic- builds essential organic molecules.
    • -respessor protien is inactive
    • -an access of the organic molecule produced by the operon can attach to repressor protien and activate it.
    • -protien binds to operator site turning it off.
  41. Inducible operon
    • -normally off but can be activated
    • -catabolic- breaks down foods
    • -repressor protien is active
    • -inducer binds to and inacivates protiens which detaches protien from operon allowing the operon gene to be activated
  42. Recombinant DNA
    DNA that has been artifically made
  43. restriction enzyme
    Cuts strands of DNA at specific location
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AP Bio
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