Sex-Linked
Single Gene Diseases
Chromosomal
Cystic Fibrosis
PKU
Hemophilia
Albinism
Chromosomal
Abnormal number of chromosomes
Non disjunctio-extra chromosome occurs
Example: Down Syndrome (trisomy 21- extra one)
Klinefelter Syndrome XXy
Turner Syndrome XO
Other examples of single cell diseases
Cystic Fibrosis- Thick mucous, one single gene for protein on cell membrane and one Chloride ion is altered, causes mucous to increase
PKU- More common in people descended from Western Europe; one single gene is missing. The gene that codes for one enzyme that digests phenylalanine. Amino acid is in most protein
Hemophilia- Group of blood-clotting disorders caused by a failure to form clotting factors VIII, IX, or XI
Albinism- Born with no skin, pigmentation, melanin in the skin and eyes, cannot go out in the sun.
Tay Sachs Syndrome- Test with a guthrie
One single gene for an enzyme involved in lipid digestion
Too many fatty compounds accumlate in the brain tissue . Can lay dormant for up to 7 months. Starts with muscle twitches, seizures, vision loss, hearing loss, fatal by the age of 4
Why is amniocentesis performed?
Can be chemically tested or used to produce a Karyotype of the developing baby
They draw out fluid from the skin cells.
What is gene therapy
the transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.
Pedigree
A chart that illistrates genetic relationships in a family over several generations.
There are ________ of genes in humans?
20k-25k
About this percent of the DNA carries active genes.
2%
The shorter arm of the chromosome is the?
The longer arm of the chromosome from from the centromere is the?
p-arm
q-arm
Which of the following increases genetic variation in the offspring?
Independent assortment and crossing over
The normal skin pigment gene “A” is dominant to the recessive albino gene “a.” A person with genes Aa
Would have normal skin pigment and would be a carrier of albinism
Which of the following is not true about the X and Y chromosomes?
Not all sex-linked diseases are carried by the Y chromosome
example of a sex-linked condition.
red/green color blindness
The single-gene disease caused by recessive genes that fail to produce the enzyme phenylalanine hydroxylase is
phenylketonuria.
The most well-known chromosomal disorder is trisomy 21, which produces a group of symptoms called
Down Syndrome
A chart that illustrates genetic relationships in a family over several generations is called a
pedigree
The procedure in which fetal tissue can be collected from the fluid surrounding the fetus is called
Aminocentisis
Which of the following is not true of genetic mutations?
They are always harmful to the cell or individual
This is the science that describes how environmental factors may result in offspring with genetic traits that cannot be explained by genes alone
EpiGenetics
This is a single gene disease which causes an impairment of ion transport across the cell
membrane.
Cystic Fibrosis
This is a single gene recessive condition that involves the failure of an essential lipid processing enzyme, hexosaminidase.
Tay-Sach
This is an epigenetic condition caused by an over-methylation of a section of DNA
Fragile X Syndrome
This condition is caused by a male having an extra X chromosome, XXY.
Klinefelter Syndrome
This condition occurs in a female with a single X chromosome, XO.
Turner Syndrome
This is a grid that is used to determine the probability of inheriting a genetic trait.
Punnett Square
This can be used to detect chromosome disorders by studying photographs of chromosomes in the process of mitosis.
What is genetics? Genetics is the study of inherited traits and their variation. What is Heredity? Heredity is the transmission of traits and biological information between generations, and genetics is the study of how traits Read more…
allele Form of a gene. Each characteristic has two alleles. recessive trait that will only appear in the phenotype if organism inherits two of them; covered up by the dominant gene gamete sex cell; sperm Read more…
hybrid An organism that has two different alleles for a trait. dominant An allele whose trait always shows up in the organism when it is present. gene The set of information that controls a trait; Read more…
