CHAPTER 27 HUMAN GENETICS
Chromosome Number in Human Cells
|Sex Cells||Body Cells|
_____________________________ - A way of looking at the chromosomes in a fetus. Amniotic fluid is taken at 14-16 weeks.
___________________ (Chorionic Villus Sampling) Tissue is taken from the fetal placenta, and chromosomes are analyzed. Taken at 10 weeks. (Pricedure is same as above)
Types of Chromosomes:
_____________________________ - Numbered chromosomes, do not determine sex (chromosomes pairs, numbers 1 through 22)
_____________________________ - Chromosomes X and Y. This pair of chromosomes determines sex of an organism.
Female Sex Chromosomes = _________ Male Sex Chromosomes = _________
The _______________________ determines the sex of a child because he may contribute either an ___ OR a ___ to that child. The _____________________ may only contribute an ___.
There is a 50/ 50 chance of having either a boy or a girl each time a couple has a baby: Do the Punnett Square
____________________ gene completely masks a _____________________ gene so that the
_____________________ is not seen at all in the person, even though it may be present.
A ____________________ gene completely masks a _____________________ gene so that the _____________________ is not seen at all in the person, even though it may be present.
Free Earlobes (_____) are dominant to attached earlobes (_____)
FF, Ff -
Ff - __________________________________
Cross two heterozygous, free earlobed persons:
A ____________________ of traits resulting in an ________________________ phenotype. NEITHER gene is totally _____________________ over the other (lack of true dominance).
Red Snapdragons (_____) are dominant to White Snapdragons (_____)
Rr - ____________________________________
rr - ____________________________________
Cross two PINK snapdragons:
_______________________________________ - A recessive genetic disorder in which Red Blood Cells are sickle (irregularly) shaped. This results in _______________________________ because sickled red blood cells cannot travel through capillaries as efficiently as round red blood cells. ______________ does not reach the tissues effectively when necessary.
This disease occurs primarily in ________________________________________
Normal Red Blood Cells (_____) are INCOMPLETELY DOMINANT to Sickled Red Blood Cells (_____). This means that HETEROZYGOTES (RR) are ___________________________________________, showing a _____________ of _______________________ This may have an advantage:
RR - ______________________________________________
Cross 2 individuals heterozygous for The Sickle Cell Gene (RR) X (RR)
|Blood Type (Phenotype)||Genotype (Genes Present)|
Blood type is determined by the Presence or Absence of _____ Proteins (or ______________): Protein ____ or Protein ____.
If a person
has ____ Protein in his blood, he will be Type ____
If a person has ____ Protein in his blood, he will be Type ____
If a person has BOTH ____ AND ____ Protein in his blood, he will be Type _____
If a person has NEITHER Proteins in his blood, he is designated Type ____
Predict the offspring of a cross between a Person Heterozygous for Type A (AO) and a person Heterozygous for Type B (BO):
Sex-Linked Traits -
Traits that are carried on the X Chromosome:
_________________ have only ONE __________ for each of these trait because they only have ONE ___________________________________. They are ____________________________ for these traits.
If there is a deletion or mistake in one of these genes, the __________ will not be able to produce ______________________ necessary for these functions they now have _____ copies of this gene! (They lost their only copy!)
Cross a Male who has normal color vision (______) with a Female who carries the gene for colorblindness (______)
__________________, sister chromatids are supposed to
_______________________ from each other. When sister chromatids of a
chromosome _____________________________________________, this results in _________ or
__________ with MORE or LESS than ______ chromosomes.
During __________________, sister chromatids are supposed to _______________________ from each other. When sister chromatids of a chromosome _____________________________________________, this results in _________ or __________ with MORE or LESS than ______ chromosomes.
· Karyotype _________________ or __________________
· Individuals have an ____________ chromosome # _______
Edwards Syndrome (Trisomy 18)
· Karyotype - ________________ or _________________
· Have an ________________ chromosome # ______
· Live no longer than ___________________
Pataus Syndrome (Trisomy 13)
· Karyotype - _______________ or __________________
· Have an ______________ chromosome # ______
· Live for approximately _________________________
· Karyotype - ________________
· ____________ stature
· Normal _______________________
· ___________________ neck
· Characteristic __________________________________
· May have ________________ or ________________ anomalies
· Karyotype - ________________
· Develop both ______________ & ________________ secondary sex characteristics
· Extremely ___________ and ___________ with ____________ limbs
· ______________________ problems
· Poor __________________________ adjustment
Dyslexia Autosomal dominant
· See/ write some letters of the alphabet or parts of words backwards
Cross a Normal Male (dd) with a Heterozygous Female, affected with dyslexia (Dd):
Achondroplasia (Dwarfism) Autosomal Dominant
· Small stature
· Short limbs, large head, low nasal bridge, prominent foerhead
Cross 2 persons heterozygous for Achondroplasia (Dd) X (Dd)
PKU (phenylketonuria) Autosomal recessive
· ___________________ in the body are not broken down properly, harming ______________ cells
· Infants are screened for the disease upon birth
· PKU patients are placed on a special ___________ to help them break down _______________ properly
Cross a heterozygous individual (Pp) with an affected individual (pp)
Cystic Fibrosis Autosomal recessive
· Individuals cannot produce a protein necessary for clearing mucus out of lungs
· Results in lung infections
· Patients die of lung infections usually in their 20s
· Predominant in Caucasians
Cross 2 parents, heterozygous carriers of Cystic Fibrosis (Ff) X (Ff)
· Red & Green look like shades of Gray
· Mostly occurs in ______________ because they only have ____ X chromosome, or ____ copy of the ___________.
Cross a Male normal for color vision (______) with a Female carrier of colorblindness (________)
Hemophilia Recessive, Sex-linked (on X chromosome)
· Individuals lack the gene that make a protein to ___________________
· Many bleed to death from open wounds because they cannot clot blood
· Blood transfusions to Hemophiliacs in the 70s & 80s increased the spread of AIDS to these patients by transfusing infected blood
· Occurs mostly in ____________ because they only have ____ X chromosome
Cross a Male Hemophiliac (______) with a normal Female (______)
The counselor creates a ______________________, a diagram that can show how a certain trait is passed along in a family. It is used to trace a family trait and predict whether future generations will have that trait.
Test such as _________________________ test to see if the child will have the disorder.
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