mutations/karyotyping

• TRUE 


  Changes in the DNA sequence may delete such protein or

  change its structure.
• Mutation it is the process in which the change in the base sequence of DNA that may affect only one gene, or they may affect whole chromosome.
• Mutation can occur in two different types of cells:

  reproductive cells and body offspring.
• Mutation affect the reproductive cells of an organism by changing the sequence of nucleotides within a gene in a sperm or an egg cell.
• Gene mutation is a permanent change in the DNA sequence that makes up a gene. It can affect the DNA at the molecular level changing the normal sequence of nucleotides base pairs.
• Point mutations is the changes in one or few nucleotides. It includes substitution, deletion, and insertions.
• Substitution it occurs when the nucleotide is replaced with different nucleotide in the DNA sequence.
• Insertion is the addition of a nucleotide to the DNA sequence.
• Deletion is the removal of a nucleotide from the DNA sequence.
• Frameshift mutation where in it shifts the reading frame of genetic message so that the protein may not be able to perform it’s function. It also include insertion and deletion.
• TRUE


  There is significance of mutation. Most are neutral, some are harmful, but some are beneficial. But in some cases, mutation can caused by mutagens in a form of medicines, chemicals, radiation, extremes of temperature, during DNA replication, and even viral infection.
• Chromosomal mutation which occurs at the chromosomal level that maybe caused by parts of chromosomes breaking off or rejoining incorrectly.
• Translocation the chromosome swap one or more gene(s) with another chromosome.
• KINDS OF CHROMOSAL MUTATIONS

  Translocation, Deletion, Insertion
• Deletion is a single chromosome mutation involving the loss of one or more gene(s) from the parent chromosome.
• Insertion one or more genes are removed from one chromosome and inserted into another chromosome.
• Example of genetic disorders that cause chromosomal mutation especially genetic syndrome

  Down syndrome, Edward's syndrome, Cri du Chat, Jacobsen Syndrome, Klinefelter’s syndrome (XXY), Turner’s syndrome
• Turner’s syndrome (X instead of XX or XY). Female sexual characteristics are present but underdeveloped. They often have a short stature, low hairline, abnormal eye features and bone development and a & "caved in” appearance to the chest.
• Klinefelter’s syndrome (XXY). Men with this condition are usually sterile and tend to have longer arm and legs and to be taller than their peers. They are often shy and quite and have a higher incidence of speech delay.
• Jacobsen syndrome is also called terminal 11q deletion disorder. This is a very rare disorder. Those affected have normal intelligence or mild mental retardation, with poor or excessive language skills. Most have a bleeding disorder called Paris-Trousseau syndrome.
• “Cri du chat” is caused by the deletion of part of the short arm of chromosome 5.
• “cri da chu” is French, and the condition is so named because affected babies make high-pitched cries that sound like a cat. Affected individuals have wide set eyes, moderately to severely mentally retarded and very short.
• Edward’s syndrome- which is the second most common trisomy after down syndrome, is a trisomy of chromosome 18. Symptoms include mental and motor retardation and numerous congenital anomalies causing serious health problems. About 99% die in infancy. However those who live past their first birthday, usually are quite healthy thereafter. They have characteristic hand appearance with clenched hands and overlapping fingers.
• Down syndrome – is usually caused by an extra copy of chromosome 21 (trisomy 21). Characteristics include decreased muscle tone, stockier build, asymmetric skull, slanting eyes and mild to moderate mental retardation.
• Human Karyotyping – is a test to examine chromosomes in a sample of cells. It can help identify genetic problems or abnormalities in chromosomes number or structure.
• Karyotyping is a laboratory procedure that allows your doctor to examine your set of chromosomes.
• The typical human karyotype contains 22 pairs of autosomal chromosomes and

  one pair of sex chromosome: XY/XX
• Sex chromosome is also called allosomal pairs.
• Human have diploid genome that contain 22 pairs of autosome and one allosomal pair.

  (46 chromosomes total)
• “karyotype” also refer to the actual collection of chromosome being examined.
• Chromosome – contain the genetic material inherited from your parents. They are composed of DNA and determine the way every human develops.
• TRUE


  When a cell divides, it need to pass on a complete set of genetic instructions to each new cell it

  forms.
• FALSE, old

  Chromosomes of new cells line up in pairs.
• Karyotype test – examines the dividing cells the pairs of chromosomes are arranged by their size

  and appearance.
• Autosome –any chromosome that is not sex chromosome.
• Genetic Disorders

  Recessive Disorders

  Sex-linked Disorders

  Human genetic syndrome
• Recessive Disorders- Happens when a child receive two defective genes from each parent.
• A person who receives one defective recessive genes is called a carrier. The carrier does not express the disorder because it is not detectable by the dominant normal genes. Therefore it can pass the defective gene to their children.
• Sickle cell anemia is a genetic blood disorder. A person who inherit two defective genes will have abnormally shaped red blood cells and may die at an early stage.
• Tay Sachs disease is characterized by the fact of an important chemical in the brain, infants who have this kind of disease usually die within their first five years.