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Genetics Vocabulary. Heredity Trait Allele Locus Characteristic Dominant Recessive. Group 1. In 1930s Heinrich Himmler of Nazi party decided to enact policy to increase numbers of “racially pure” citizens considered “Aryan” Blonde Blue eyes (green ok )
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Genetics Vocabulary Heredity Trait Allele Locus Characteristic Dominant Recessive Group 1
In 1930s Heinrich Himmler of Nazi party decided to enact policy to increase numbers of “racially pure” citizens considered “Aryan” • Blonde • Blue eyes (green ok ) • Since he understood principles of heredity, convinced blonde-haired, blue-eyed soldiers and women to breed more children, married or not • Entire organization called Lebensborn which means “fountain of life” in ancient German
Lebensborn 1935 - 1945 Special attention was paid to children born on Fuhrer’s birthday, October 7
Royal intermarriage was a common practice in Europe through the ages to keep pure royal bloodlines. • The Hapsburg lip is a trait that was found in the House of Hapsburg royal line in which the bottom lip protrudes as a result of an under bite. • Many royal portraits of the Hapsburgs shows this common trait that was passed down through the generations.
Feather color in certain chickens is a gene that is determined by two alleles, white and black. • If a chicken has two white alleles, it will be white. If a chicken has two black alleles, it will be black. • If a chicken has one white allele, one black allele, it will not be gray, but actually checkered with both black and white feathers!
Kidney gene locus Cancer gene locus • Certain cancer genes on different chromosomes cause cancer to different organs depending on the locus of the gene • On chromosome 9, the cancer gene’s locus is near a locus for kidneys. As a result, there is a higher incidence of kidney cancer when those two loci are physically close. Chromosome 9
Each President of the United States seems to have a physical quirk or characteristic that distinguishes him from the others. • Barack Obama’s quirky characteristic seems to be his big ears which are excellent fodder for comedians worldwide.
Current evolutionary theory holds that human beings evolved from primates in central Africa. • The first humans were dark-haired, dark-skinned, with dark-eyes. • Current genetic models show that all dark traits are dominant over lighter traits, since those lighter traits are a result of mutations. Artist’s interpretation of an early ancestor.
Tay Sachs disease is a recessive disease which means that a person has to have both Tay Sachs recessive alleles. • Many people in the Ashkenazi Jewish community are carriers. • When two parents who are carriers have children, each child has a 1 in 4 chance of getting the disease.
Genetics Vocabulary Genotype Phenotype Homozygous Heterozygous Monohybrid Dihybrid Group 2
A b C D e f G A B C d e F G Genotype for eye color, Bb • The specific genetic makeup of an individual makes up its genotype. • If one could visually see a genotype, it might be represented by a series of letters, each one an allele, on the chromosomes. • If a gene for brown eyes is represented by the letter b, brown would be B since it is dominant. Therefore, blue would be b since it is recessive. • This explains how one can have a genotype Bb but still have brown eyes. From Dad From Mom h i J k L M H i j k L m Chromosome 2
Being a carrier of an allele does not necessarily mean the individual expresses that trait. • If the trait is recessive, the carrier will NOT show the phenotype, as in blue eyes. • If the trait is dominant, the carrier WILL show the phenotype, as in a cleft chin. • Expression of the trait is the phenotype. It’s the observable trait that is seen with the eyes, or seen as a disease.
Phenylketonuria (PKU) is a homozygous recessive genetic disorder. • It’s characterized by an inability to utilize the essential amino acid phenylalanine due to a malfunctioning enzyme that can’t break it down. • Without this enzyme, phenylalanine accumulates in the blood and body tissues. • Untreated, it can cause mental retardation and death. • For an individual to develop PKU they must be homozygous for that allele.
b b Bb Bb B b bb bb
Polydactyly is a condition in which a person has more than five fingers per hand or five toes per foot. • The individual is heterozygous dominant for that genetic trait.
Anne Boleyn, was married to Henry VIII, the King of England in the 1500’s. • It was reported that she had an extra finger (polydactyly?) which she kept hidden. • When Henry wanted to marry another woman, he accused her of adultery with her own brother and also used the extra finger against her, saying that she was a witch. • She was beheaded by an expert swordsman with one swift stroke!
One of the most common hybrids in the animal kingdom is a mule. • A mule is a cross between a male donkey (a jack) and a female horse (a mare). • Mules are always sterile. Since donkeys have 62 chromosomes and horses have 64, mules have 63. This means they can’t produce gametes since ½ of 63 = 31.5!
Genetics Vocabulary Law of segregation Law of independent assortment Punnett square Probability Pedigree Group 3
How does an individual have blue eyes when both parents have brown eyes? • This is the result of the law of segregation. • Remember that the genotype for brown eyes can be BB or Bb. • For an individual to have blue eyes they had to receive the two bb alleles (one from each parent). • In order for this to happen it meant that during gamete formation (sperm or eggs), the B and b allele had to separate become different gametes. • During fertilization two gametes with b alleles would join producing an individual with blue eyes.
B b B b B b B b b b Mom Dad B GAMETES Blue Eyed zygote
Law of Independent Assortment • This is one of Mendel’s laws of heredity. He wanted to know whether the inheritance of one gene was influenced by the inheritance of a different character. • He conducted dihybrid crosses using 2 pairs of contrasting characters and found that alleles of different genes separate independently of one another during gamete formation. • We now know that this law only applies to genes that are located on different chromosomes or that are far apart on the same chromosome.
