Exam_4_Study_Guide-2007 - Exam 4 Study Guide Pay particular...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Exam 4 Study Guide Pay particular attention to the human situation as you study for this exam. Chapter 16 Learn what can be done with plants as a consequence of their tolerance of polyploidy. - Plant engineering o Generate a monoploid plant from a diploid o Generate a drug resistant monoploid plant by selecting for grotwth in the presence of the herbicide o Generate a herbicide resistant diploid from the resistant monoploid. Colchicine inhibits mitotic spindle formation Use Colchicine for one cell division (1n ---> 2n) o Triploid Plants (3n): Problems during meiotic segregation (sterile) o Tetraploid x Diploid = Triploid Arise spontaneously from accidental doubling (2n to 4n) or use Colchicine. Larger plant and fruit Understand the human consequence of aneuploidy. ---> Result from non- disjunction during meiosis. - Leads to trisomy or monosomy conditions o Trisomy (2n + 1) Trisomy 21 (Down Syndrome) Klinefelter XXY o Monosomy (n) Turner Patau Understand the consequence of each class of chromosomal mutation. - Changes in chromosomal structure: o Deletions, duplications, inversions, translocations - Balanced rearrangements o Change in gene order o Not deleterious unless the breakpoint Is in an essential gene - Unbalanced rearrangements o Change in gene dosage (i.e. duplication and/or deletion of a chromosomal region) o Deletions are more detrimental than duplications - Chromosomal rearrangements A. Deletion: Loss of data o Fatal if homozygous o Formation of deletion loop o Never revert to WT - Pseudodominance o Deletion will uncover recessive alleles (recessive phenotype is expressed)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
B. Duplications: Gain of chromosomal region - 3 copies/ cell in a diploid - Difficult to detect phenotypically - Tandem/reverse duplications C. Inversions - Chromosomal region rotated 180 degrees - If heterozygous (from an inversion loop) o Par A centric inversion Centromere is outside of the inversion X-over between paracentric inversion and WT = dicentric/acentric chromosomes ACENTRIC FRAG LOST (not attached to spindle fiber) DICENTRIC BRIDGE SNAPS (as spindle fibers pull the chromosome to both poles)
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/17/2008 for the course BIOL 222 taught by Professor Babitzke,paullee during the Fall '07 term at Pennsylvania State University, University Park.

Page1 / 7

Exam_4_Study_Guide-2007 - Exam 4 Study Guide Pay particular...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online