10: Chromosomal Basis Of Inheritance Flashcards
How many autosomes are there?
22
What is a karyotype?
A complete set of metaphase chromosomes
How are regions of the chromosome numbered?
From the centromere
Elaborate 17q21.
Located on the large arm of chromosome 17 and is the 21st gene from the centromere
Define telocentric
Chromosome with only 2 arms
Acrocentric
Satellite
Submetacentric
Uneven arms
Metacentric
Even arms
Are spores diploid or haploid
Haploid
What do spores mature to form?
Male and female gametophytes
Is the sporophyte generation diploid or haploid?
Diploid
What supports the chromosome theory of inheritance?
The correlation between gene segregation patterns and the pattern of chromosome behavior in meiosis
In genotypic sex determination, what is sex determined by?
Sex chromosomes
In genic sex determination, what is sex determined by?
Other genes, not the sex chromosomes
What is the XY system?
xx = female xy = male
What is the xo system?
xx = female xo = male
(Grasshopper)
What is the zw system?
Zw is female
zz is male
(Birds, moths, fish)
What gene determines the sex in humans?
Testis determining factor (tdf)
What is the x chromosome-autosome balance system?
Sex is determined by the ratio of x to autosomes
What is the difference between primary nondisjunction and secondary nondisjunction?
Primary - occurs on normal set of sex chromosomes (rare)
Secondary - occurs on an abnormal set of sex chromosomes
What is the frequency of turner syndrome?
1/10,000
What causes turner syndrome?
XO (44 autosomes and 1 X)
What causes klinefelter syndrome?
XXY
What is the lyon hypothesis?
The barr body is a highly condensed, transcriptionally inactive x-chromosome
