Module 2: Cell Division & Chromosomes Flashcards
Diploid
- A cell that has 2 chromosomes
- 2n
Haploid
- A cell that has 1 chromosome
- Reproductive cells
- 1n
Constitutional Abnormalities
- Present in every cell or in most cells
- Ex: Down Syndrome
Acquired (Somatic) Abnormalities
- Present in only certain cells/tissues
- Can result in disease expression but weren’t present at birth
- Usually found in cancer
Numerical Abnormalities
- Either missing chromosomes or have extra
- Aneuploidy & polyploidy
Polyploidy
A chromosomal mutation where there is too few or too many sets of chromosomes
Aneuploidy
- A chromosomal mutation where there is 1 or more too many or too few chromosome
- Ex: Down Syndrome
Structural Abnormalities
- Normal number of chromosomes but individual chromosomes aren’t normal
- Translocations, partial deletions/duplications, rings chromosomes
Translocations
-Chromosome breaks and a portion of it reattaches to a different chromosome
Rings Chromosomes
A mutated chromosome whose ends have fused together to form a ring
Inversions
- Part of the chromosome is broken off and flipped over
- DNA is there but isn’t in the right orientation
Robertsonian Translocations
- No info on the P arm
- Occurs on chromosome 13, 14, 15, 21, 22
Unbalanced Translocations
Result in net gain and/or loss of genetic info
Unbalanced Translocations
Result in net gain and/or loss of genetic info
Reciprocal Translocations
- Doesn’t affect the individual but it can affect the gametes they produce
- Could result in a miscarriage
Duplications & Deletions
- Come from chromosomal inversions
- Has correct number of chromosomes but some bands might be missing/extra
Somatic cells are produced utilizing which process?
Mitosis
Trisomy 21 (Down Syndrome) is an example of ____.
- Constitutional abnormality
- Numerical abnormality
- Aneuploidy
What are the possible findings for someone with a balanced reciprocal translocation?
- No physical or health problems
- Increase risk for miscarriage
- Increased risk for a child w/ disabilities
An individual with chronic myeloid leukemia (CML) most likely has normal blood chromosomal studies (True/False)
True
What is required for the gain or loss of genes in the gametes of an individual that carriers a balanced inversion?
Crossing over
Meiosis
- The formation of egg and sperm cells (germ cells)
- Results in 4 sex cells
Mitosis
- Replication of somatic cells (all cells except germ/sex cells)
- Results in 2 identical daughter cells
