Whole Chromosome Mutations Flashcards
(24 cards)
What are the two major categories of whole chromosome mutations?
Aneuploid mutations
Euploidy mutations
What are aneuploid mutations?
Aneuploid mutations - change the karyotype by a fraction of a set, such as one extra chromosome or one missing chromosomes
What are euploidy mutations?
Euploidy mutation - change the karyotype by the whole set!
Changes in the number of chromosomes in eukaryotes result from _______ or ______.
Changes in the # of chromosomes are the result of:
- accidents of nuclear division
- result from inter-species fertilization (and the consequences of these fertilizations)
What does the term 1X mean?
1X = one complete set of chromosomes
What does the term 2X mean?
2X = two complete sets of chromosomes
Normal diploids are _____.
Normal diploids are 2X and have two complete sets of chromosomes.
True or False:
Aneuploidy is a condition in which the chromosome number of an individual is NOT an exact multiple of the ‘2X’ number of chromosomes.
False:
Aneuploidy is a condition in which the chromosome number of an individual is NOT an exact multiple of the ‘1X’ number of chromosomes.
ANEUPLOIDY
Creating genetic imbalance by having an extra chromosome is like having a big duplication.
Missing a chromosome is like _____
Creating genetic imbalance by having an extra chromosome is like having a big duplication.
Missing a chromosome is like having a big deletion.
When is an aneuploid called monosomic?
An aneuploid is called monosomic because there is only one copy of the relevant chromosome.
When is a aneuploid called nullisomic?
An aneuploid is called nullisomic when there is no copy of the relevant chromosome.
Tetrasomic
When an aneuploid has two extra copies of the same chromosome
What are the sources of most aneuploid errors?
They are errors in INDIVIDUAL chromosome’s segregation, either during mitosis or meoisis.
What is primary non-disjunction?
If CHROMOSOMES fail to go to opposite poles at the FIRST MEIOTIC DIVISION, this is called primary non-disjuction.
What is the most common source of aneuploidy?
Primary non-disjunction
Primary non-disjunction produces how many abnormal products?
Primary non-disjunction produces 4 abnormal products.
What is secondary non-disjunction?
When chromosomes go to opposite poles in first meiotic division but SISTER CHROMATIDS fail to go to opposite poles during SECOND MEIOTIC DIVISION.
For secondary nondisjunction, how many of the four products are abnormal?
Two (of the four)
What is mitotic non-disjunction?
What does it produce?
Mitotic non-disjunction occurs if sister chromatids fail to go to opposite poles during mitosis.
This produces two abnormal nuclei.
Another source of aneuploidy is _______ ______ ____.
This produces one normal cell and one cell that is missing a chromosome.
Another source of aneuploidy is mitotic chromosome loss.
This produces one normal cell and one cell that is missing a chromosome.
What is trisomy?
Trisomy is the condition of having an extra copy of one chromosome.
What are euploids?
Organisms that have exact multiples of the monoploid number.
Euploid changes are due to:
Euploid changes are due to:
- failure of nuclear division
- result of inter-species fertilization and its consequences
What are polyploids?
Individual with more than 2 sets of chromosomes
