Deletions

1
Deletions

• Segment of chromosome is missing
• A . B C D E F G H
• A . B C D E
• terminal deletion
• A . B C G H
• interstitial deletion

2
Duplication

• Segment of chromosome doubles
• A . B C D E F G H
• A . B C D E F D E F G H
• interstitial tandem duplication
• A . B C D E F F E D G H
• interstitial reverse duplication

• A . B C D E F G D E F H
• displaced duplication
• A . B C D E F G H F G H
• terminal tandem duplication
• A . B C D E F G H H G F
• terminal reverse duplication

3
Crossing over

• 2-strand single (2SE)
• 2-strand double (2SD)
• 2-strand triple (2ST)
• 3-strand double (3SD)
• 4-strand double (4SD)

4
Problem

• You study a plant heterozygotic for a terminal
  reverse duplication. The duplicated area pairs
  with the normal chromosome. A 2SD cross over
  occur. Sketch meiosis in this organism.

5
Problem

• You study a plant homozygous for an interstitial
  tandem duplication. Show the different possible
  pairing configurations. Is it possible to obtain
  a gamete containing a triplication?