6.1 Chromosomal Mutations Flashcards
What are chromosomal mutations also known as?
aberrations
What are chromosomal mutations?
alterations to the chromosome including increases or decreases in total number, deletions or additions to segments, or complete rearrangments
How are chromosomes arranged?
in sets
What is aneuploidy?
addition or loss of one autosomal chromosome but NOT the set
What is the loss of a single chromosome referred to as?
monosomy (2n-1)
What is the gain of a single chromosome referred to as?
trisomy (2n+1)
What are the most common examples of aneuploidy?
monosomy and trisomy
What results from monosomy in the X chromosome?
developmental and health problems but NOT lethal
What results from monosomy in autosomal cells?
lethal
Where is monosomy more tolerated?
in plant kingdom
Which is more tolerated in animals: monosomy or trisomy?
trisomy
What is the general rule of trisomy in an animal and its lethality?
the smaller the chromosome the less lethal
What does trisomy usually change in plants?
phenotype
What is trisomy 21 known as?
down syndrome
What is the only human trisomy in which individuals routinely live longer than a year?
down syndrome
Who first discovered trisomy 21 and when?
Langdon Down in 1866
What is the prevalance of down syndrome in children?
1 in 700
What is the average lifespan of an individual with down syndrome?
50 years
What increases the risk of having a child with down syndrome?
increased maternal age
What is usually the cause of death in an individual with down syndrome?
alzheimers
