Genetic Tools

Genetic Tools Pedigree Karyotype DNA Fingerprinting

The Human Genome: A genome is all the DNA in an organism.

Human Karyotype

A karyotype is an organized profile of a person's chromosomes Extra, missing, or abnormal positions of chromosome pieces can cause problems with a person's growth, development, and body functions.

Girl Boy Autosomal Chromosomes (Pairs 1-22) Sex Chromosomes (23rd pair)

Correct Meiosis Process 4 Haploid Daughter Cells Nondisjunction in Meiosis I 2 Daughter Cells with Extra Chromosome 2 Daughter Cells with Missing Chromosome Nondisjunction in Meiosis II 2 Haploid Daughter Cells 1 Daughter Cell with Missing Chromosome 1 Daughter Cell with Extra Chromosome

What is the sex of the child? Is there a chromosomal disorder? On which chromosome pair is the disorder located?

Down Syndrome Mothers in early 20s - 1 in 1,500 births Mothers over 35 - 1 in 70 births Mothers over 45 - 1 in 25 births Symptoms/Characteristics: Decreased muscle tone Small ears/mouth Excess skin at neck Slowed physical/mental development Heart problems

Turners (45, XO) 1 in 3,000 female births Sterile females

Klinefelters (XXY) 2 in 1000 male births Sterile males

Geneticists Wanted Very intelligent scientists to help diagnose the genetic conditions for these children? Jaxton's Story - Trisomy 18

Background: Mr. and Mrs. Raider are excited about their new pregnancy, but some of their doctor visits have shown that the child seems to be developing at a slower rate. They are concerned for the child’s health just like any other parent and have come to you for help. Jaxton's Story - Trisomy 18

Child A

Child B

Child C

Child D Cri du Chat – Partial 5 Deletion

Child E wolf hirschhorn karyotype – Partial 4 Deletion

Child F Jacobsen Syndrome – Partial 11 Deletion

DNA (transcription) mRNA  (translation) Proteins (A.A.) Today we will take the district Common Assessment over Gene Expression and Genetics. We will also begin moving into our Forces of Evolution unit by watching a video about the Galapagos Islands. What are the names of the steps that take place to turn our genetic code of DNA into proteins, and what are the molecules that do the work? DNA (transcription) mRNA  (translation) Proteins (A.A.)

(At times, genotype can also be determined) Pedigree – tool used to show phenotype through multiple generations in a family. (At times, genotype can also be determined) I II III This pedigree shows the appearance of a widow’s peak in three generations of a student’s family. What are the probable genotypes of the student’s parents? W – Widow’s Peak w – No Widow’s Peak

Jane and Joe Smith have dimples, but their daughter, Clarissa, does not. Joe’s dad has dimples, but his mother, and his sister, Grace do not. Jane’s dad, Mr. Renaldo, her brother Jorge, and her sister Emily do not have dimples, but her mother does.

Using a Pedigree – Cystic Fibrosis (Autosomal Recessive)

DNA fingerprinting DNA Fingerprinting is a procedure where the sequence of genetic information (DNA) in a person's cells is analyzed and identified.

DNA Fingerprinting Crime labs can use any cell from a person’s body left behind at a crime scene to match them with DNA samples. What form of DNA might be left behind and how?

A DNA test was performed. Lt. Russ is investigating a murder scene. The attacker was scratched by his victim and some of his skin cells were found under the victim’s fingernails. A DNA test was performed. Which of the suspects is most likely the murderer? Evidence

DNA Fingerprinting can also be used to determine paternity. A woman claims that a famous athlete is the father of her child. All three gave DNA samples. Use #1 to see if she is telling the truth. M-mother C- child F- father

Sex-Linked Inheritance

Why do you think sex linked disorders are more common in males than females? Dominant Recessive

Sex-Linkage Genes that are carried on the X chromosome are called Sex-linked genes. Traits determined by sex-linked genes are called sex-linked traits. Because of this, sex-linked traits are most often seen in males who only have one copy of the X chromosome.

Since traits are sex-linked, there is usually a distinct pattern. Sex-linked traits Since traits are sex-linked, there is usually a distinct pattern. For example, color blindness is a sex-linked trait whose allele is recessive and located on the X chromosome.

Conditions caused by sex-linked genes -Hemophilia -Colorblindness -Duchene Muscular Dystrophy -Male patterned baldness Amoeba Sisters - Sex Linked Traits

Sex-Linkage Female- (XX) She must have two recessive alleles to express the recessive phenotype. Male- (XY) He only needs one recessive allele to express the recessive phenotype.

Color blindness is a “sex-linked” trait. What do you think that means? Color Blindness Explanation Colorblindness Test Colorblindness #2

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X X - Woman w/ normal vision. Example: X X - Woman w/ normal vision. X X - Woman w/normal vision; Carrier for colorblindness. X X - Colorblind woman. X Y - Man w/normal vision. X Y - Colorblind man. Carrier - Heterozygous for a recessive trait. C C C c c c C c

Colorblind mother Normal Father X Y X c Y c Y X X C c X C c c X c X Results:

Colorblind mother Normal Father X Y c X c Y X X C c c Y X c X C c X Results: Female Carriers/ Male colorblind