GEN LAB FINALS

• Genome - complete set of chromosomes in a cell
• In diploids, there are two sets of homologous chromosomes(2X)
• the number of chromosomes in each genome is equivalent to the haploid number
• in Oryza sativa, 2n=24, the haploid number of rice is n=12
• Euploidy Involves the entire set of chromosomes in a cell.
• Euploidy

  An extra copy of DNA can cause multiple malfunctions in an organism, more so a whole copy of a chromosome.
• Euploidy

  more tolerated in plants than in animals
• euploidy

  diploidfuse with haploids to triploid
• euploidy

  in plants, triploids can produce sterility, able to produce more f leshy fruits
• euploidy

  Can cause the difference in the production of secondary metabolites
• Monoploidy

  only one set of chromosomes.
• Monoploidy

  Meiosis is very abnormal. No synapsis
• monoploidy

  univalents only
• monoploidy

  Sister chromatids may segregate meiosis I
• monoploidy

  Almost completely sterile since the gametes produced do not usually contain a complete genome
• monoploidy

  by chance, haploid gametes may have formed.
• If fertilization occurs, diploid condition is restored.
• Polyploidy

  ● More than two complete sets of chromosomes.
• In some polyploids, genomes are identical, which is called autopolyploid.
• autopolyploids- same capital letters
• allopolyploids- different capital letters letters or subscript
• autotriploid- AAA
• allotetraploid- aabb / a1a1a2a2
• Allohexaploid– three different genomes(AABBDD)
• higherpolyploids- 4 genomes
• Triploidy

  ● Three complete sets of chromosomes.
• Triploidy

  Meiosisis abnormalsince synapsis is disturbed.
• Triploidy

  Valents formed:

  ○ Trivalent (III)

  ○ Bivalent &aunivalent (II +I)

  ○ Threeunivalents (I+I+I)
• chains of three chromosomes may be observed during diakinesis
• laggards may be observed at Anaphase I
• Tetraploidy

  ● 4 complete sets of chromosomes.
• Autotetraploids- four identical genome(AAAA)
• Allotetraploid– 2 different genome pairs (AABB).
• Meiosis in autotetraploid is much distributed
• tetraploidy

  Irregular meiotic pairing
• tetraploidy

  Valentsformed:

  ○ quadrivalent (IV)

  ○ oneunpaired(III + I)

  ○ 2bivalents (II + II)

  ○ 4univalents (4 I or I+I+I+I)
• Aneuploidy

  ● Consists of mutations that involve

  changes in the number of

  chromosomes in the genome.
• Aneuploidy

  Due to either addition or loss of one or more whole chromosomes during meiosis
• Aneuploidy

  After meiosis one ofthe4daughter cells will chromosome
• Tetrasomy (2n+2)

  Have two extra copies of chromosomes.