Gizmo Simulation: Human Karyotyping
How many total autosomes do human cells have?
44
Why do you think humans have two sets of 23 chromosomes?
Humans have two sets of 23 chromosomes because you get a set from your mother and the other set from your father, resulting in two sets.
What aspects of the genome can and cannot be determined through karyotyping?
Karyotyping can give information on an individual's sex and on chromosomal disorders. Karyotyping does not give any information on the specific traits encoded in an individual's genes.
Secondary sex characteristics fail to develop properly; testicular changes take place in puberty, which typically results in infertility
Klinefelter Syndrome
How do you think sex is determined in a person with a chromosomal disorder involving the sex chromosomes?
Sex is determined by the presence or absence of a Y chromosome. Males have Y chromosomes while females do not.
What sex would a person with trisomy X be?
female
Which type of chromosomal disorders seems to have the greatest affect on a person's health—disorders involving autosomes or sex chromosomes?
Disorders involving autosomes have the greatest effect on health.
Poor muscle tone; slanting eyes with folds of skin at the inner corners; short and broad hands and feet; small head; respiratory problems; speech problems; visual problems; hearing loss; heart defects and gastrointestinal problems possible; slow intellectual development.
Down syndrome
How do you think different people's chromosomes would compare?
Most humans have 46 chromosomes of approximately the same size and shape. The only major difference between different people's chromosomes can be found in the sex chromosomes. Males have an X and Y chromosome. Females have two X chromosomes. Different people's chromosomes compared would be greatly different because the resulting chromosomes in the offspring depend and come from the parents' chromosomes. Even siblings have very different chromosomes because of crossing over and independent assortment which result in genetic variation.
Why do you think this might be the case?
Syndromes involving sex chromosomes have symptoms related to the development of sex characteristics, rather than the functions of major body systems. Thus, most of the genes located on sex chromosomes probably only code for reproductive system traits. The genes on other chromosomes code for essential life functions. Therefore, autosomal disorders would involve genes that are necessary to a person's survival. Because of this, autosomal disorders would be more deadly.
On the SIMULATION pane, compare the X and Y chromosomes. Which chromosome do you think has more DNA? Explain
The X chromosome is larger, and thus has more DNA than the Y chromosome
Examine the chromosomes labeled X and Y. How do these two chromosomes compare?
The X chromosome is much larger than the Y chromosome
Faulty development of ovaries and sex hormone production; menstruation and pregnancy usually not possible; short stature
Turner Syndrome