Genetics Vocabulary Group 1 Heredity Trait Allele Locus Characteristic Dominant Recessive

Genetics Vocabulary

Group 1

HeredityTraitAlleleLocusCharacteristicDominantRecessive

Word Meaning Examples

heredityhe•red•i•ty (noun)

The passing of genetic traits from parent to offspring.

Her red hair is a result of heredity from her mother’s side of the family.

Most cases of male-pattern baldness is heredity.

Latin: hereditas = heirship

• 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

Writing Task:

Heinrich Himmler understood the principles of heredity when he instituted the “Lebensborn” project to increase the number of blonde-haired, blue-eyed “Aryans” in Germany.

Pair-Share

•I received my mother’s ___________ as a result of heredity.

A

•I received my father’s ____________ as a result of heredity.

B

Word Meaning Examples

traittrait (noun)

A genetically determined characteristic or condition.

My dad’s Roman nose is a trait that goes back generations.

Monica’s weird feet are a trait she definitely did not inherit from her mom.

Latin: tractus = tract

• 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.

Writing Task:The Hapsburg lip is a trait found in one royal family line as a result of years of intermarriage in order to preserve the royal bloodlines.

Pair-Share

•One trait I inherited is ___________ which is from my _______________.

A

•A second trait I inherited is _______ which is from my _______________.

B

Word Meaning Examples

alleleal•lele (noun)

One of the alternative forms of a gene that governs a characteristic, such as hair color.

If just one allele for eye color is brown, you will have brown eyes.

One allele for a gene comes from your mother, the other from your father.

German: allelomorph = changing gene

• 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!

Writing Task:

A chicken having two black feather alleles will result in it being black. If it has one black allele and one white allele, it will be checkered, both black and white.

Pair-Share

•A gene that has two alleles is _____.A

•Another gene that has two alleles is _________.B

Word Meaning Examples

locuslo•cus (noun)

loci (plural)lo•ci

1. The place where something is situated or occurs.

2. The position in a chromosome of a particular gene or allele.

Geneticists are working on finding the locus for the skin cancer gene.

The repeated DNA sequence GCGCGCG is found at many loci on chromosome 12.

Latin: stlocus = a place

• 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

Kidney gene locus

Cancer gene locus

Writing Task: Depending on the loci for certain genes, cancer can affect organs if they are located near the cancer locus on the same chromosome.

Pair-Share

•The locus of my house is _________.A

•The main loci for fights on campus is ___.B

Word Meaning Examples

characteristicchar•ac•ter•is•tic (noun)

A distinguishing trait, quality, or property.

One of Mr. Jones’ unique characteristics is his funny laugh.

Elizabeth Taylor’s violet eyes are a distinguishing characteristic.

Greek: charaktiras = a mark

• 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.

Writing Task:

Each individual has unique physical characteristics that are inherited from his or her parents. Everything from hair color, to ear size, to eye color is handed down through the generations.

Pair-Share•One characteristic I inherited from my _________ is ______________.

A•One characteristic I inherited from my _________ is ______________.

B

Word Meaning Examples

dominantdom•i•nant noun,adjective)

Commanding, controlling, or prevailing over all others.

Brown eyes are dominant over blue eyes as a result of evolution.

That student is a dominant presence in my 6th period class.

Latin: dominari = strong

• 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.

Writing Task: Why are blonde hair and blue eyes such revered traits in Hollywood when brown hair and brown eyes are dominant traits possessed by most of the world?

Pair-Share

•Dominant traits found in my family are __________.A

•A dominant trait NOT found in my ______ is __________. B

Word Meaning Examples

recessiverecessive (adjective, noun)

1. Withdrawn

2. Describes a trait or an allele that is expressed only when two recessive alleles for the same characteristic are inherited.

I hope she doesn’t keep her feelings recessed.

My cousin’s green eyes must be recessive since both parents have brown eyes.

Latin: recedere = to go back

• 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.

Writing Task: Some diseases are recessive which means an affected individual must have both recessive alleles, one from each parent.

Pair-Share

•A recessive disease that runs in my family is __________.A

•____________ is a recessive trait.B

Genetics Vocabulary

Group 2

GenotypePhenotype HomozygousHeterozygous MonohybridDihybrid

Word Meaning Examples

genotypege•no•type (noun)

1. The entire genetic makeup of an organism.

2. The combination of genes for one or more specific trait.

The genotype for white flowers on a pea plant must be pp since it is a recessive trait.

If that man has Huntington disease, his genotype must be Hh.

Latin: genus= birth, race, kindGreek: typos = type

• 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.

AbCDefG

ABCdeFG

hiJkLM

HijkLm

From Dad From Mom

Chromosome 2

Genotype for eye color, Bb

Writing Task:

All of an individual’s DNA is its genetic makeup or its genotype. The genotype refers to the alleles that makeup the genes on a chromosome.

Pair-Share

•The genotype for a Tay Sachs carrier is ____.A

•A blue eyed individual might have the genotype _______.B

Word Meaning Examples

phenotypephe•no•type (noun)

An organism’s appearance or other detectable characteristic that results from the organism’s genotype and environment.

The pea plant’s purple flower is one of its many observable phenotypes.

Luis’ light brown eyes are a unique phenotype that makes him stand out in a crowd.

Greek: phainein= to show +typos = type

• 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.

Writing Task:If a person expresses the allele, it is then called a phenotype. An example of a phenotype is having a cleft chin.

Pair-Share

•A phenotype that I express is ____.A

•A different phenotype that my partner possesses is ___________________.

B

Word Meaning Examples

Homozygousho•mo•zy•gous (adjective)

Describes an individual that has identical alleles for a trait on both homologous chromosomes.

Individuals who have the genotype AA are homozygous for that trait.

Albino animals are homozygous for defective fur or skin pigment alleles.

Greek: homos = same or similar + zygous = yoked (joined)

• 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.

Writing Task:

An individual who is homozygous for a particular gene has two copies of the same allele. This can have serious consequences if the gene results in a genetic disorder such as PKU.

Pair-Share

•A homozygous recessive disorder is ____________.A

•Homozygous alleles result in an individual having ___________.B

Word Meaning Examples

HeterozygousHet•ero•zy•gous (noun)

Describes an individual that has two different alleles for a particular trait.

My uncle was heterozygous for sickle cell anemia which protected him from malaria.

I am heterozygous for brown eyes since my dad has green eyes.

Greek: Heteros= other + zygous = yoked (joined)

b

bb

Bb Bb

bb

b

b

B

• 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!

Writing Task:Polydactyly is a heterozygous dominant disorder where the dominant allele is expressed giving the individual extra fingers or toes.

Pair-Share

•An example of heterozygous alleles is _____.A

•Individuals heterozygous for dominant freckles, F, have the genotype _____.

B

Word Meaning Examples

hybridhybrid (noun, adjective)

MonohybridDihybrid

The offspring of two animals or plants of different breeds, varieties, or species.

That new Toyota Prius hybrid car gets a whopping 51 MPG!

The mythological griffin is a hybrid of a lion’s body and an eagle’s head and wings.

Latin: hybrida = uncommon

• 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!

Writing Task: Mules are hybrids of male donkeys and female horses. Mules can never reproduce since they have 63 chromosomes.

Pair-Share•A common dog hybrid is a _______.A

•A great mythological hybrid would be a _____ which is a cross between ___.

B

Genetics Vocabulary

Group 3

Law of segregation Law of independent assortmentPunnett squareProbability Pedigree

Word Meaning Examples

Segregationsegregation (noun)

1. To separate or set apart from others.

2. (Genetics)The separation of alleles for a character that occurs during meiosis.

Sex cells contain one copy of an allele for each gene as the result of the law of segregation.

Racial segregation in schools lasted until the mid 1960’s.

Latin: segregatus = apart from herd

• 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 bMom B bDad

B b B b

GAMETES

b b

Blue Eyed zygote

Writing Task: During meiosis, alleles for the same characteristic will separate into different gametes according to the law of segregation.

Pair-Share•In orthodox synagogues there is segregation between _____ and _____.

A

•I have observed segregation ________.B

Word Meaning Examples

Assortmentassortment (noun)

The act of distributing into groups of a like kind.

Students are invited to lunch where an assortment of sandwiches and soda will be served.

Our salad contains an assortment of vegetables including lettuce, celery, tomatoes, and carrots.

French: assortir = to sortLatin: sort = a category, set

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.

Writing Task: In dihybrid crosses, the alleles will separate independently of one another demonstrating the law of independent assortment

Pair-Share• I have an assortment of

____________ in my ____________.

A• The movie theater has an

assortment of _________________ in the lobby.

B

Word Meaning Examples

Probabilityprob·a·bil·i·ty (noun)

The likelihood that a specific event will occur. It can be expressed in words, decimals, percentages and fractions.

The probability of rain in Los Angeles in July is about one percent.

The probability of winning the lottery is about 18 million to 1!

Latin: probare = to test, to prove

Probability• Probability is a very interesting branch of

mathematics because it is used to predict the likelihood of random events. It is a deductive science that studies uncertain quantities related to random events.

• Gregor Mendel used the general rules of probability to explain the basic principles of heredity by breeding green peas in planned experiments. After hundreds of experiments he predicted that the outcome of any cross with pure bred plants would always result in a probability of 3 to 1 in the F2 generation.

• Probability = Number of one kind of possible outcome Total number of all possible outcomes

Example:• A coin tossed into the air will land on heads

(one possible outcome). The total of all possible outcomes is two – heads or tails.probability= 1

2

Writing Task: The cross between 2 pure bred pea plants will always result in a probability of 3 to 1 in the F2 generation.

Pair-Share• The probability of rain

___________ is _________.A• The probability of getting an

A in _________ is ___________.

B

Word Meaning Examples

Pedigreeped·i·gree (noun)

1. A family history that shows how a trait is inherited over several generations.2. The recorded purity of a breed of individuals.

From my family pedigree I traced freckles back to Uncle George.

A five generation pedigree of my family reveals where detached earlobes originated.

Anglo French: pie de grue = literally foot of the crane

Pedigree

The meaning of pie de grue literally comes from the “foot of the crane” as the pedigree diagram looks similar to the branches coming out of a crane's foot.

• Many animals are bred for their pedigrees.

• The Mastiff, one of the oldest dog breeds, can be seen in pictures dating back to 3000 BC.

• The dogs were bred for their large size and strength.

• The Romans used them as opponents against lions and gladiators.

• The British used them to fight off predators on farms and as protectors of the home.

• They are also bred for their gentle temperament and fierce loyalty.

Pedigree

Writing Task: Mastiff dogs have a pedigree that pre- dates the Romans. They are bred for their strength, size, temperament and fierce loyalty.

Pair-Share• A pedigree can show how

_____________.A• The pedigree that runs

through my family is ________________.

B

Genetics Vocabulary

Group 4

Sex-linked traitColor blindHemophilia Fragile X syndromeMuscular dystrophy

Word Meaning Examples

Sex-linked trait

(adjective)

A trait that is determined by a gene found on one of the sex chromosomes, or such as the X chromosome in humans.

Martha didn’t know that she could be a carrier of a sex-linked trait if only males become infected with the disease.

The sex-linked trait color blindness affects about 8% of males in some manner.

Latin: sexus = genderOld English: hlanc = chain

• Most sex-linked traits are a result of a genetic defect of one or more genes located on the X chromosome.– Since females require two X

chromosomes, one normal X will override the defected one. Those females are considered carriers.

– Since males only have one X chromosomes, the inheritance of the defective X from their mothers results in them being affected with the trait.

Word Meaning Examples

Color blind(adjective)

An individual who is affected with partial or total inability to distinguish one or more chromatic colors, usually a sex-linked trait.

Her husband picks out his clothes in the morning since he has red-green color blindness.Only 0.5% of women are color blind as it is sex-linked and needs 2 affected X chromosomes.

Latin: celare = to conceal + Old German: blint = blind

• Humans see light with the retina which is made up of rods and cones.– Rods gives us our night vision but can’t

see color.– Cones are not useful at night but see

color during daylight hours.• Three different types of cones ,

red, green, and blue, detect the wavelengths of all the hues of the rainbow.• Defects in these cones cause

problems in detecting certain colors.

The colors of the rainbow as viewed by a person with no color vision deficiencies.

The colors of the rainbow as viewed by a person with protanopia.

The colors of the rainbow as viewed by a person with deuteranopia.

The colors of the rainbow as viewed by a person with tritanopia.

Word Meaning Examples

hemophiliahe•mo•phil•i•a

(noun)

Hemophiliache•mo•phil•i•ac

(adjective)

A sex-linked hereditary blood defect characterized by delayed clotting of the blood and consequent difficulty in controlling bleeding even after minor injuries.

Greek: haima = blood + philia = to love

Word Meaning Examples

Fragile X syndrome

Fragile X syndrome

(noun)

Word Meaning Examples

Muscular dystrophy

muscular dystrophy

(noun)

Genetics Vocabulary

Group 5Autosomal Albinism Cystic fibrosisTay SachsPhenylketoneuriaHuntington’s diseaseDwarfismNeurofibromatosis

Genetics Vocabulary

Group 6

Incomplete dominancePolygenic inheritanceCodominance