Errors During Meiosis Flashcards
What steps provide the potential for chromosomal abnormalities
crossing over and independent assortment
Many errors produces gametes that…
- cannot survive
- cannot survive and produce a zygote
How does an error in meiosis impact all the cells in the offspring?
All the cells will contain the error
During crossing over, what happens?
The chemical bonds that hold the DNA together in the chromosome are broken and reformed.
What is an example of the chromosome not reforming correctly?
unequal crossing over or non-homologous pairs may cross over
What are some errors to chromosome structure
deletion, duplication, inversion, translocation
What is a deletion in chromosomes?
a piece of the chromosome is deleted, and genes are lost
What is a duplication in chromosomes?
a section of a chromosome appears two or more times in row
What is an inversion in chromosomes?
a section of the chromosome in inverted
What is a translocation in chromosomes?
a segment of one chromosome becomes attached to a different chromosome (non-homologous chromosomes exchange genetic information)
Name diseases caused by chromosome mutations
- Cri du chat
- charcot-marie tooth disease
- FG Syndrome
Chronic Myelogenous Leukemia - XX Male Syndrome
What causes cri du chat?
a deletion in chromosome 5
What are symptoms of children with cri do chat?
they cry with a high-pitched, catlike sound, low birth weight, widely spaced eyes, recessed chin, and developmental and cognitive delays
Is there a cure for cri do chat
no
what causes charcot-Marie tooth disease?
a duplication of a gene on chromosome 17
what are the symptoms of charcot-Marie-Tooth Disease
muscle weakness, loss of some sensation in the lower legs, feet and hands, a high foot arch with a constantly flexed tow.
Is there a cure for Charcot-Marie-Tooth Disease?
no
What is Chronic Myelogenous Leukemia
it is a cancer of the white blood cells
What causes Chronic Myelogenous Leukemia
a translocation between chromosome 9 and 22
What is the treatment for CML?
using a drug that stops the increased production of white blood cells that the abnormal gene causes
How is XX male syndrome caused?
a translocation between X and Y chromosomes. The gene that makes a human male is found on the Y chromosome (SRY gene) is accidentally transferred to the X chromosome during crossing-over. It will result in an XX chromosome that is male rather than female
What are symptoms of XX gene?
small testicles, sterile, poor facial hair growth, development of breasts in the male
define non-disjunction
when homologous chromosomes pairs or sister chromatids do NOT separate
When can non-disjunction occur?
in anaphase I or anaphase II
