Genetics and Inheritance - Exam Questions Flashcards
How many chromosomes does the normal human karyotype have?
46 chromosomes
Which phase are chromosomes in a karyotype in?
Metaphase
Bands on chromosomes as seen on a karyotype are referred to as…?
G-bands
Where is the centromere in a metacentric chromosome?
The centromere located approximately in the middle
An acrocentric chromosome has:
a. multiple centromeres
b. the centromere located approximately in the middle
c. a short arm and long arm of significantly different lengths
d. a short arm consisting only of a satellite
e. no centromere
d. an acrocentric chromosome has a short arm consiting only of a satellite
In the context of a chromosome, what does p refer to?
The short arm
In the context of a chromosome, what does q refers to?
The long arm
In the context of a chromosome, what is a satellite?
A small part connected to the centromere by a stalk
What percentage of spontaneous abortions are caused by chromosomal abnormalities?
50%
What is Down’s syndrome, in cytogenetics nomenclature, referred to as?
47, XX or XY, +21
What is Down’s syndrome characterised by?
Simian crease of the palm
What chromosomal mutation is Patau syndrome?
Trisomy 13
Children born with Edward’s syndrome:
a. generally survive to adulthood
b. often have polydactyly
c. usually die within the first year of life
d. often suffer from seizures
e. usually die between the ages 12 and 18 years
c. Children born with Edward’s syndrome usually die within the first year of their life
What does Klinefelter’s syndrome result in?
A male phenotype which can appear normal
A male phenotype with normal female karyotes…
…results if the SRY region appears on an X chromosome
