Biology 12

incomplete dominance

The phenotype of the heterozygote is intermediate (middle, blended) between those phenotypes expressed by the homozygotes.

d. Colorblind father to pass the gene on to his son.

Because the gene for red-green colorblindness is located on the X chromosome, it is normally not possible for a: a. carrier mother to pass the gene on to her daughter b. carrier mother to pass the gene on to her son. c. colorblind father to pass the gene on to his daughter. d. colorblind father to pass the gene on to his son.

karyotype

Chart of metaphase chromosome pairs arranged according to length and location of the centromere, used to pinpoint unusual chromosome numbers in cells.

(Blending) Incomplete dominance is a phenotype of heterozygous individuals. An example would be hair color. (See both traits) Codominance is both phenotypes of both homozygous to be produced in heterozygous individuals. An example of this would be a black chicken. Both are the conbinations of 2 different alleles.

Compare and contrast incomplete dominance and codominance. Give an example of each.

Females sex chromosome is represented by X. Eye color is an example of a trait that is carried in the X chromosome. Males sex chromosome is represented by Y. Male pattern baldness is an example of a trait that is carried in Y chromosome. Example: red/green color blindness.

Explain how some traits are expressed differently in males and females. Give an example of such a trait.

Pedigree

Graphic representation of genetic inheritance used by genetics to map genetic traits.

codominance

Pattern where phenotypes of both homozygous parents are produced in heterozygous offspring so that both alleles are equally expressed.

completely dominant alleles

Phenotypes of both heterozygous and homozygous dominant individuals have the same phenotype.

codominant alleles

Phenotypes of both homozygotes are produced in the heterozygote.

sex-linked trait

Traits controlled by genes located on sex chromosomes.

sex linked traits

Traits controlled by genes located on the X or Y chromosome.

d. 25% black, 50% blue, 25% white

A cross between a white rooster and a black hen results in 100% blue Andalusian offspring. When two of these blue offspring are mated, the probable phenotypic ratio seen in their offspring would be: a. 100% blue b. 75% black, 25% white c. 75% blue, 25% white d. 25% black, 50% blue, 25% white

fetus

A developing mammal from nine weeks to birth.

carrier

An individual heterozygous for a specific trait.

carrier

Another name for a heterozygous individual.

autosome

Pairs of matching homologous chromosomes in somatic cells.

pedigree

A graphic representation of an individual's family tree.

D. Huntington's disease

A human genetic disorder caused by a dominant gene is: a. Tay-Sachs disease b. cystic fibrosis c. PKU d. Huntington's disease

Hemizygous was choosen because males have XY and can only posess 1 allele.

A male is said to be hemizygous for genes on the X chromosome. Explain why you think this term was chosen.

multiple alleles

A trait controlled by four alleles is said to have?

A chromosomal abnormality is a human that has 3 autosomal chromosomes. The karyotype would then have 47 chromosomes.

Describe a chromosomal abnormality found in human. What would the person's karyotype look like?

An example of codominance in humans is a group of inherited red blood cell disorders called sickle-cell anemia. Blood type AB.

Describe in detail an example of codominance in humans.

ABO blood group is an example of a single gene that has multiple alleles in humans. Blood type for gene I codes attach to the membrane protein found on the surface of red blood cells. Your immune system will recognize the red blood cells belonging to you. Then it cells with a different surface molecule enter your body your immune system will attack them.

Describe in detail an example of multiple alleles in humans.

An example of polygenic inheritance in humans is skin color. The skin color is controlled by 1, 3, & 4 genes. You can tell that it is polygenic in a population by the people having different types of skin color. Many different phenotype.

Describe in detail an example of polygenic inheritance in humans. How can you tell that a trait is polygenic just by looking at a population?

A disease that is passed on in a simple dominant fashion is Huntington's disease. This disease results in a breakdown of certain areas of the brain. There is no effective treatment for this disease.

Describe one disease that is passed on in a simple dominant fashion.

One disease that is passed on in a simple recessive fashion is Phenylketonuria. This occurs because of the absence of an enzyme that converts one amino acid phenylalanine to a different amino acid throsine. (PKU) results from absence of an enzyme that converts one amino acid to a different amino acid.

Describe one disease that is passed on in a simple recessive fashion.

Some external environmental influences that affect genes are temperature, nutrition, light, chemicals and infection agents.

Describe some external environmental influences that can affect genes.

Some internal environmental influences that affect genes are age, male pattern, baldness.

Describe some internal environmental influences that can affect genes.

You can tell if a trait is due to polygenic inheritance by them having many different phenotypes. An example in humans would be skin color. Wide range/variety of traits. Phenotype - physical. Genotype - alleles that you pocess. (spelling?????)

How can you tell if a trait is due to polygenic inheritance? Give an example in humans.

Incomplete dominance is when traits are inherited in a pattern where the phenotype of heterozygous individuals is intermediate between those of two homozygotes. This is different from multiple alleles because they are traits controlled by more then 2 alleles. Blood type A, B, AB, O - 4 or more phenotypes.

How does incomplete dominance differ from multiple alleles?

Mendelian inheritance are dominant traits. No blending. Either dominant or recessive, either purple or white not alot of phenotypes. Polygenic inheritance is the inheritance pattern of a trait that is controlled by 2 or more genes. Alot of different phenotypes

How does polygenic inheritance differ from Mendelian inheritance?

autosomes

Humans have 22 pairs of these types of chromosomes.

50%

If a female fruit fly heterozygous for red eyes (XRXr) crossed with a white-eyed male (XrY), what percent of their offspring will have white eyes?

sex chromosome

In human the 23rd pair of chromosomes, determine the sex of an individual and carry sex linked characteristics.

polygenic inheritance

Inheritance pattern of a trait controlled by two or more genes, genes maybe the same or different chromosomes.

polygenic inheritance

Inheritance pattern of a trait controlled by two or more genes.

simple recessive heredity

Inheritance pattern of phenylketonuria (PKU) and Tay-Sachs disease.

incomplete dominance

Inheritance pattern where the phenotype of a heterozygote is intermediate between those of the two homozygous neither allele of the pair is dominant but combine and display a new trait.

Traits that are passed on in dominant are cleft chin, hairline and earlobe types.

List some traits that are passed on in a simple dominant fashion.

multiple allele

Presence of more that two alleles for a genetic trait.

Sex chromosomes

The 23rd pair of chromosomes that differ in males and females are called?

No, he will not be nearsighted because nearsightedness is found on the X chromosome. Father is XY. Father will pass the Y to the son.

The gene for nearsightedness in humans is found on the X chromosome. A boy has a nearsighted father. Will the boy be nearsighted? Explain.

A sex linked trait are traits controlled by genes located on sex chromosomes. (X or Y chromosome) They are inherited from the ex chromosome X or Y usually X. Ex: color blindness, male pattern baldness.

What are sex linked traits and how are they inherited differently from other traits? Give an example

By looking at a persons Karyotype you can identify unusual numbers of chromosomes in an individual. If its going to be a boy or a girl.

What can you tell about a person just by looking at a karyotype?

A sex linked trait are traits controlled by genes located on sex chromosomes. Red-green color blindness is an example of one in humans. This is caused by the inheritance of a recessive allele at either of two gene sites on the X chromosome.

What is a sex-linked trait? Give an example of one in humans.

(Blending) An incomplete dominance is a phenotype of heterozygous individuals is intermediate between those of the two homozygous. An example would be a homozygous red flowered plant crossed with a homozygous white flowered plant. All F1 offspring would have pink flowers. (ex. hair color).

What is incomplete dominance, and give an example.

(See both Traits) (both show up). Codominance is both phenotypes of both homozygous to be produced in heterozgous individuals (both alleles are expressed equally). Incomplete dominance when both heterozygous and homozygous have the same phenotype. Example of codominance would be a black and white feathered chicken. Red and white flower mix and make a striped flower.

What is the difference between incomplete dominance and codominance? Give an example of codominance.

Multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color). Polygenic inheritance is inheritance pattern of a trait controlled by two or more genes. Can be on the same chromosome or different. (ex: sstem is controlled by 3 different genes and each gene is a different chromosome.

What is the difference between multiple allele inheritance and polygenic inheritance? Give an example of each.

codominant alleles

When roan cattle are mated, 25% of the offspring are red, 50% are roan, and 25% are white. Upon examination, it can be seen that the coat of a roan cow consists of both red and white hairs. This trait is one controlled by?

Blood typing is important because catagorizes the blood, and lets us know what blood type we are. This lets us know what type of blood we can receive.

Why is blood-typing important?

autosomes Explanation: Autosomes do not fit because they do not fit with the making of the offspring. The sex chromosomes are indicated by the X and Y chromosomes, and the traits controlled by genes located on sex chromosomes are sex linked traits. (Sex linked trait are on the sex chromosome).

Write the term that does not belong in the list. Then explain your choice. autosomes, X and Y chromosomes, sex-linked traits, sex chromosomes.

phenotype Explanation: Phenotype does not belong because it describes the way an organism looks. While genotype, heterozygous, and homozygous have something to do with alleles. Describing the genotype.

Write the term that does not belong in the list. Then explain your choice. genotype, phenotype, heterozygous, homozygous

homozygous Explanation: The Carrier is heterozygous.

Write the term that does not belong in the list. Then explain your choice. heterozygous, carrier, homozygous