What is the charge of DNA? DNA has a negative charge
What are the charges of the electrodes on the electrophoresis box? They are positively charged.
How does DNA move through the electrophoresis box? The positive charge of the red line in the electrophoresis box attracted the negatively charged DNA.
How do large pieces of DNA move compared to small pieces?
Large pieces of DNA move slower then the small pieces because it takes them longer to get through the obstacles of the agarose gel.
What is the purpose of the micropipet? What are the two stops? What unit does it measure in? The micropipet pours the DNA into the wells made by the comb. The first stop is to load the DNA, the second is to inject the DNA. The micropipet measures in micro liters (uL)
What is the purpose of the comb and the gel bed?
The comb is to create wells to put the DNA in, and the gel bed is used to hold the agarose gel.
What are the steps of DNA fingerprinting?
- Get the DNA sample
- Cut it using restriction enzymes.
- Put it through Gel Electrophoresis
- Compare the different DNA’s
Why do scientists perform DNA fingerprinting?
Scientists use DNA fingerprinting to convict felons, determine paternal cases, etc.
What type of DNA did we use?
We used viral DNA
Where do Scientists obtain their DNA from?
From blood, hair, skin, anything that contains cells.
Meiosis-Sexual Reproduction or a means of producing new individuals by the union of two sex cells.
Meiosis Steps
Division I –
A Reduction Division
Interphase
-Chromosomes replicate just like in mitosis.
Prophase I
-Homologous chromosomes pair forming a tetrad (4 chromotids).
-The process of pairing is called synapsis.
Metaphase I
Tetrads are pulled to the center of the cell forming an “Equatorial Plate”.
Anaphase I
One of each homologous chromosome pair is pulled to the poles after the centromere is split.
The homologs are separated randomly so maternal and paternal chromosomes could (and usually do) end up on the same side of the dividing cell.
Telophase I
Cytokinesis completes the first division producing two haploid(number of chromosomes in a gamete) cells that contain one set of chromosomes in a replicated state.
The nucleus briefly reappears.
Interkinesis
A brief period between the two Meiotic divisions.
***Because of the complexity of Metaphase I, anomalies such as crossing over and nondisjunction can occur.
Nondisjunction: When a centromere doesn’t split causing a daughter cell to receive an extra chromosome, while the other daughter cell doesn’t get any.
Crossing Over: During Metaphase I chromosomes paired by synapsis can become tangled. Tangling can result in pieces of chromosomes being exchange (crossing over).This means maternal traits can be swapped to a paternal chromosome and vice versa.
Duplication: A result of unequal crossing over. During metaphase I, a chromosome may break off and exchange genes unequally with its homolog.
Once chromosome will get additional genes (duplication) while the other chromosomes will be lacking those genes completely.
Deletion: The chromosome that lacks genes as a result of crossing over.
Division II - A Mitotic Division of Haploid Cells
***The second Meiotic division goes through all the normal phases of Mitosis (Prophase II, Metaphase II, Anaphase II, and Telophase II).
The sole purpose of the second division is to separate chromatids just like Mitosis does.
Genetics- The science of heredity and how traits are inherited
Heredity- the passing of traits from parents to offspring.
Mendel-1866, Father of Genetics worked with pea plants. Pea plants fertilize themselves, they have both gametes. They self pollinate. Mendel experimented with pea plants and learned a lot about genetics. He is called the Father of Genetics. He studied flower color, stem length, etc. He crossed pea plant purple flowers with white flower, he transferred the spores/pollen, they all turned out to have purple flowers, showing that purple was a dominate trait.
Mendelian Trait-Human traits that are controlled by a single gene with only two alleles.
Homozygous Dominant-2 of the same alleles that overpowers or hides the other trait.
Homozygous Reccessive-2 of the same alleles that are the weaker trait that is hidden or masked.
Heterozygous-2 different alleles. A hybrid or a mix.
Punett Squares-shows a cross between the parents with all the genotypes/phenotypes of the offspring.
Monohybrid Cross- A 1 trait cross.
Dihybrid Cross- A two trait cross.
Alleles- a form of a gene which codes for one possible outcome of a phenotype. (For example- T for Tallness and t for shortness)
Multiple Alleles- 3 or more alleles that code for a trait.
Incomplete Dominance/Codominance- If there are only two alleles involved in determining the phenotype of a certain trait, but there are three possible phenotypes, then the inheritance of the trait illustrates either incomplete dominance or codominance.
Incomplete Dominance: Codominance:
Humans have 23 pairs of chromosomes.
Sex linked traits-Somatic(nonsexual) traits that are controlled by genes found on sex chromosomes.
Autosomes-Chromosomes that control somatic(nonsexual) development.
Somatic cells-Body cells. Normal somatic cells are diploid(2N) and contain one set of chromosomes from each parent.
Blood Types- A,B, AB, O
Antigions- Blood cells contain structures in the cell membrane called antigens. Your immune system recognizes your blood cells based on antigens.
Antibodies- An antibody is a molecule able to bind itself to molecules of a complementary shape called antigens, and recognize them.
Universal Donor- Type O is the universal Donor because it has no antigens on it, so the antibodies of other blood cells accept type O as a blood cell.
Universal Reciever- Type AB is the universal receiver because it accepts all other blood types because it has no antibodies.
Human Pedigree-A family record that shows how a trait is inherited for several generations.
Humans have 23 pair chromosomes, out of those chromosomes pair 23 is the only sex chromosomes. If you have an XX then the offspring is a female. If you have XY then the offspring is a male. Pair 23 also carries the sex-linked traits.
Pair 1-22 are autosomal chromosomes and carry most traits.
Cloning
Sheep- When scientists cloned Daly in 1997 they took the udder cell from the sheep they wanted to clone. Then they took the egg of an unfertilized egg. They removed the DNA from the egg, and put in the DNA from the male udder cell. They then fused the DNA and egg together with electricity. Then they put it into a Culture with growth promoting protein hormones. Then they implanted the embryo into a surrogate sheep.
Cows-look at that white sheet that looks like eggs in a pan.
Pro’s and Con’s
Genetic Disorders
Down Syndrome-Most common autosomal chromosome abnormality with an incidence of 1/800. Occurs in all ethnic groups. 95% is due to meiotic non-disjunction(When a chromosome pair fails to separate correctly during meiosis, resulting in reproductive cells which have missing or extra chromosomes). Most of the time the extra chromosome is inherited from the mother. A transfer of a chromosomal segment to a new position is seen in 3-4% of cases, about half of which are new, and half are relating to the family. Mosaicism(A condition in which tissues of genetically different types occur in the same organism) is seen in 1-2% of children.
The recurrence risk depends upon the etiology(cause or origin of disorder as determined by medical diagnosis) In cases with non-disjunction and de novo translocation the risk is about 1% plus the maternal age risk. Familial 21/21 translocation have 100% recurrence risk. Theres a 2-5% risk if the carrier is the father and 10-15% risk if the carrier is the mother.
Individuals with Down syndrome have characteristic faces and typical minor anomalies (Deviation or departure from the normal).
In this day and age people with Trisomy 21 have lived healthier and longer lives and are better integrated into society. And can be cared for better.
Fragile X Syndrome-Most common cause of inherited mental retardation with incidence of 1 in 2000 males, and 1 in 2500 females. The carrier frequency in females is 1/259 and in males is 1/755. Fragile X is an X-linked disorder in all ethnic groups. Responsible for 10% of all cases of inherited mental retardation and 30% of X-linked mental retardation. Gene responsible for Fragile X is located on the X chromosome. Within the FMR1 gene is a specific region of CGG repeats. Individuals with fewer than 40 repeats are not at risk to pass fragile X syndrome to their offspring. Individuals with 55-200 repeats are said to carry FMR! Permutation. Male’s with over 200 repeats have fragile X syndrome. Females with more than 200 repeats have 50-70% risk to have a low or borderline IQ and 30-50% chance to have a normal IQ. Vast majority of cases are the result of expansion of the CGG triplet repeat within the FMR1 gene. Expansion occurs when the gene mutation is passed from the mother to the child.
If a mother carries the gene mutation, she is at a 50% risk to pass the gene mutation on to her child. If a father carries the gene premutation, he will pass the gene mutation on to his daughters in the premutation state. None of his sons will inherit the gene mutation.
The FMR1 gene produces the FMR1 protein (FMRP). In individuals with more than 200 repeats, the gene usually becomes methylated resulting in the gene being turned off. When the FMR1 gene is turned off, FMRP is not produced. It is the lack of FMRP that causes the cognitive features and connective tissue findings of fragile X syndrome.
Lifelong monitoring of health status, including mental health, for all patients diagnosed with fragile X syndrome is suggested. Life span is usually normal for these individuals. With changes occurring in society which promote inclusion of persons with disabilities, individuals with fragile X syndrome are likely to be cared for in a wide variety of medical settings.
Turner Syndrome-3) Turner Syndrome
Introduction
Turner syndrome is a condition in females characterized by short stature, gonad abnormalities, and a variety of other major and minor anomalies due to the lack of a normal second sex chromosome. It is the most common female sex chromosome abnormality, occurring in approximately 1/2500 female live births.
Conclusion
Intelligence is usually normal in individuals with Turner syndrome. However, many individuals with Turner have difficulty with visual-spatial relationships and there is an increased incidence of attention deficit disorder which may interfere with school performance. Therefore, it is recommended that a developmental evaluation be performed prior to starting school. Most women with Turner syndrome can expect Cystic Fibrosis.
Cystic Fibrosis- Cystic fibrosis (CF) is the most common, fatal hereditary disease in the U.S.
CF is a disorder of the cells that line the lungs, small intestines, sweat glands and pancreas. Sticky, thick mucus contributes to the destruction of lung tissue and impedes gas exchange in the lungs. It also prevents nutrient absorption in the small intestines, and blocks pancreatic ducts from releasing digestive enzymes. Approximately 85% of all people with CF cannot properly digest their food without supplemental enzymes.
People with CF exhibit some or all of these common symptoms, to varying degrees:
salty-tasting skin
excessive appetite along with poor weight gain
loose, foul-smelling stools
persistent cough, wheezing or pneumonia
Other symptoms may include the following:
clubbed fingers
digestive disorders
smaller than average in height and weight
susceptibility to heat prostration and dehydration
male sterility
diabetes and/or liver disorders
CF patients are frequently hospitalized for chronic lung infections and digestive disorders.
People with CF must follow a strict regimen for the treatment of this disease. This regimen includes taking medications such as antibiotics to fight respiratory infections, enzymes to aid in food digestion, and vitamins to improve general health. Some people with CF use aerosols to open restricted airways. To dislodge mucus from the lungs, people with CF must undergo chest physical therapy or other therapy methods; in some cases, they must use oxygen. People with CF also must follow a strict diet, and avoid people with colds or infections.
Hemophilia- Hemophilia A is a hereditary blood coagulation disorder caused by a deficient activity of plasma protein factor VIII, which affects the clotting property of blood.
Causes, incidence, and risk factors
Hemophilia is a group of hereditary bleeding disorders of specific blood clotting factors classified as hemophilia A and B. Hemophilia A is the most common of these disorders and is the result of a deficiency of clotting factor VIII.
The disorder is caused by an inherited sex-linked recessive trait with the defective gene located on the X chromosome. Females carry two copies of the X chromosome, and therefore if the factor VIII gene on one chromosome is defective, the gene on the other chromosome can compensate. Males, however, carry only one X chromosome, so if the factor VIII gene on that chromosome is defective, they will have the disease.
Females with one defective factor VIII gene are carriers of this trait. Fifty percent of the male offspring of female carriers have the disease and 50% of their female offspring are carriers. All female children of a male hemophiliac are carriers of the trait.
The severity of symptoms can vary with this disease, and the severe forms become apparent early on. Bleeding is the hallmark of the disease and sometimes, though not always, occurs if an infant is circumcised. Additional bleeding manifestations make their appearance when the infant becomes mobile.
Mild cases may go unnoticed until later in life when they occur in response to surgery or trauma. Internal bleeding may happen anywhere, and bleeding into joints is common. Risk factors are a family history of bleeding and being male.
The incidence of hemophilia A is 1 out of 5,000 men.
Prevention
Genetic counseling
Prenatal intrauterine diagnosis with termination of pregnancy as an option
Symptoms
Bruising
Spontaneous bleeding
Bleeding into joints and associated pain and swelling
Gastrointestinal tract and urinary tract hemorrhage
Blood in the urine or stool
Prolonged bleeding from cuts, tooth extraction, and surgery
Signs and tests
Coagulation studies involving many tests are performed if the person tested is the first one in the family to have a bleeding disorder. Once the defect has been identified, other family members will need less testing to diagnose the disorder.
Huntington’s Disease- HD) is a devastating, degenerative brain disorder for which there is, at present, no effective treatment or cure. HD slowly diminishes the affected individual's ability to walk, think, talk and reason. Eventually, the person with HD becomes totally dependent upon others for his or her care. Huntington's Disease profoundly affects the lives of entire families: emotionally, socially and economically.
Named for Dr. George Huntington, who first described this hereditary disorder in 1872, HD is now recognized as one of the more common genetic disorders. More than a quarter of a million Americans have HD or are "at risk" of inheriting the disease from an affected parent. HD affects as many people as Hemophilia, Cystic Fibrosis or muscular dystrophy.
Early symptoms of Huntington's Disease may affect cognitive ability or mobility and include depression, mood swings, forgetfulness, clumsiness, involuntary twitching and lack of coordination. As the disease progresses, concentration and short-term memory diminish and involuntary movements of the head, trunk and limbs increase. Walking, speaking and swallowing abilities deteriorate. Eventually the person is unable to care for him or herself. Death follows from complications such as choking, infection or heart failure.
HD typically begins in mid-life, between the ages of 30 and 45, though onset may occur as early as the age of 2. Children who develop the juvenile form of the disease rarely live to adulthood. HD affects males and females equally and crosses all ethnic and racial boundaries. Each child of a person with HD has a 50/50 chance of inheriting the fatal gene. Everyone who carries the gene will develop the disease. In 1993, the HD gene was isolated and a direct genetic test developed which can accurately determine whether a person carries the HD gene. The test cannot predict when symptoms will begin. However, in the absence of a cure, some individuals "at risk" elect not to take the test.
Since the discovery of the gene that causes HD, scientific research has accelerated and much has been added to our knowledge
Sickle Cell Anemia- Sickle Cell anemia is a group of inherited red blood cell disorders. Normal red blood cells are round like doughnuts, and they move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and shaped like sickles used to cut wheat. When these hard and pointed red cells go through the small blood tube, they clog the flow and break apart. This can cause pain, damage and a low blood count, or anemia.
What makes the red cell sickle?
There is a substance in the red cell called hemoglobin that carries oxygen inside the cell. One little change in this substance causes the hemoglobin to form long rods in the red cell when it gives away oxygen. These rigid rods change the red cell into a sickle shape instead of the round shape.
How do you get sickle cell anemia or trait?
You inherit the abnormal hemoglobin from your parents, who may be carriers with sickle cell trait or parents with sickle cell disease. You can not catch it. You are born with the sickle cell hemoglobin and it is present for life. If you inherit only one sickle gene, you have sickle cell trait. If you inherit two sickle cell genes you have sickle cell disease.
Is Sickle Cell only in African Americans?
Sickle cell is in many nationalities including African Americans, Arabs, Greeks, Italians, Latin Americans, and those from India. You can be Caucasian and have sickle cell disease or trait. All races should be screened for this hemoglobin at birth.
What are the Complications?
Complications from the sickle cells blocking blood flow and early breaking apart include:
pain episodes
strokes
increased infections
leg ulcers
bone damage
yellow eyes or jaundice
early gallstones
lung blockage
kidney damage and loss of body water in urine
painful erections in men (priapism)
blood blockage in the spleen or liver (sequestration)
eye damage
low red blood cell counts (anemia)
delayed growth
What can be done to help prevent these complications?
Sickle cell patient should be under the care of a medical team that understands sickle cell disease. All newborn babies detected with sickle cell disease should be placed on daily penicillin to prevent serious infections. All of the childhood immunizations should be given plus the pneumococcal vaccine. Parents should know how to check for a fever because this signals the need for a quick medical checkup for serious infection. The following are general guidelines to keep the sickle cell patient healthy:
Taking the vitamin folic acid (folate) daily to help make new red cells
Daily penicillin until age six to prevent serious infection
Drinking plenty of water daily (8-10 glasses for adults)
Avoiding too hot or too cold temperatures
Avoiding over exertion and stress
Getting plenty of rest
Getting regular check-ups from knowledgeable health care providers
Patients and families should watch for the following conditions that need an urgent medical evaluation:
Fever
Chest pain
Shortness of Breath
Increasing tiredness
Abdominal swelling
Unusual headache
Any sudden weakness or loss of feeling
Pain that will not go away with home treatment
Priapism (painful erection that will not go down)
Sudden vision change
Tay Sachs Disease-
What is Tay-Sachs Disease?
Tay-Sachs disease is a fatal genetic disorder in which harmful quantities of a fatty substance called ganglioside GM2 accumulate in the nerve cells in the brain. Infants with Tay-Sachs disease appear to develop normally for the first few months of life. Then, as nerve cells begin to swell and expand with fatty material, a relentless deterioration of mental and physical abilities occurs. The child becomes blind, deaf, and unable to swallow. Muscles begin to deteriorate and paralysis sets in. A much rarer form of the disorder which occurs in patients in their twenties and early thirties is characterized by unsteadiness of gait and progressive neurological deterioration. Patients with Tay-Sachs have a "cherry-red" spot in the back of their eyes. The condition is caused by insufficient activity of an enzyme called hexosaminidase A that catalyzes the biodegradation of acidic fatty materials known as gangliosides. Gangliosides are made and biodegraded rapidly in early life as the brain develops. Patients and carriers of Tay-Sachs disease can be identified by a simple blood test that measures hexosaminidase A activity. Both parents must be carriers in order to have an affected child. When both parents are found to carry a genetic mutation in hexosaminidase A, there is a 25 percent chance with each pregnancy that the child will be affected with Tay-Sachs disease. Prenatal monitoring of pregnancies is available if desired.
Is there any treatment?
Presently there is no treatment for Tay-Sachs.
What is the prognosis?
Even with the best of care, children with Tay-Sachs disease usually die by age 5.
Dominant or Recessive?
Hair color-Dominant-dark hair. Recessive-Blond Hair, red hair
Eye color-Brown or Hazel-Dominant….. Recessive-blue or gray
Height-Short-dominant Tall-recessive
Tasters PTC-Tasting is Dominant, not tasting is recessive
Hemophilia-Is sex-linked recessive
Hair texture-Curly Hair-Dominant Recessive-straight hair
Ear lobe attachment-Attached is recessive, Free earlobes are dominant.
Widows peak-Dominant, straight hair line is recessive.
Deaf Mutism-Is recessive
Brachydactyly-Is dominant
Siamese Twins Video- 1 in a million to 1 in a half million are Siamese twins.
Dyne has more control
Seperation depends on which organs they share.
