Bio Lab 10

Which choice below best demonstrates the difference between a genotype and phenotype?

Genotype is a letter that represents the genes and phenotype is the physical description of the expression of those genes.

Which of the following statements is FALSE?

Matings between individuals with dominant phenotypes cannot produce offspring with recessive phenotypes.

Multiple Alleles 2: Blood type: There are three alleles for blood type A, B and O. A and B are both dominant to "O" and codominant to each other (meaning an AB person has AB blood type).If Brian has blood type 'O', his father has blood type 'O', but his mom has bloodtype 'A', what is the genotype of his mom's blood?

Mom must be blood genotype AO

If a round pea has a wrinkled parent and wrinkled is recessive, the round pea is

Rr.

Genotype

The DNA that determines physical appearance

Phenotype

The actual physical appearance in an organism

A phenotypically normal woman marries a man with CMT disease, an autosomal dominant disorder. They have a son who has CMT disease. How did the son get it? Charcot-Marie-Tooth disease (CMT) is a neurological disorder named after the three physicians who first described it in 1886

The father had at least one dominant allele, which he passed on to his son.

Which choice below best describes the difference between an allele and a gene?

There is a gene region for chile preference, there is an allele for a red preference and an allele for a green preference.

Codominance effects occur when the different alleles both are seen in the phenotype.

True

Codominance occurs when

both of the alleles in a heterozygote are expressed phenotypically in an individual.

What is the ratio of phenotypes in the offspring produced by the cross Aa x Aa? Assume complete dominance for the trait.

c. 75% dominant: 25% recessive

In the human ABO blood grouping, there are four basic blood types, type A, type B, type AB, and type O. The blood proteins A and B are

codominant

If, in a heterozygous individual, only one allele is expressed in the phenotype, that allele is

e. dominant.

The genetic makeup of an individual is its

genotype.

The resulting pink flowers which occur after crossing red and white snapdragons is most likely a result of ________.

incomplete dominance

In Japanese four o'clock flowers, pink-flowered plants are produced when red-flowered plants are crossed with white-flowered plants. This type of inheritance can best be described as

incomplete dominance.

In snapdragons, red x white pink. This pattern of inheritance is explained by

incomplete dominance.

Independent assortment happens in

metaphase I of meiosis

The espression of freckles in a person involves 27 different alleles for the gene for a receptor protein, involves a protein that binds to the receptor, and is influenced by the sun. Freckles is therefore a trait that is ____________________________.

multifactorial

The blood types of humans are an example of ________.

multiple alleles

The physical appearance of a character is the ________ while the genetic constitution is the ________.

phenotype; genotype

A recessive gene is one

whose effect is masked by a dominant allele.

Sickle-cell disease: This disease results from the inheritance of a pair of mutated alleles that produce abnormal hemoglobin protein. Red blood cells are filled with hemoglobin, and a person with Sickle-cell disease produces abnormal hemoglobin that will cause the red blood cell to collapse, or sickle, under oxygen stress. Sickle-cell disease gives some resistance to malaria, and is found in populations that have historically lived in areas where malaria is prevalent.If Felicia has Sickle-cell disease, and her husband Troy is homozygous normal for hemoglobin, predict the risk of their children inheriting the disorder.

100% non-disease

PKU: PKU is short for phenylketonuria, a recessive disorder that results from a mutation in the gene for an enzyme that breaks down phenylalanine, an amino acid. Newborns are testedfor this disorder at birth, and if they have PKU they will start a diet that restricts their phenylalanine intake, and allowing them to develop normally. If both parents are carriers (heterozygous, Nn) for the disorder, predict the risk of their children inheriting the disorder. Set-up and complete a Punnett square and match the correct genotype and their ratios from the list given.

25% NN: 50% Nn: 25% nn

In Mendel's experiments, if the gene for tall ( T) plants was incompletely dominant over the gene for short ( t) plants, what would be the result of crossing two Tt plants?

25% tall; 50% intermediate; 25% short

If an individual who is homozygous for type B blood marries a heterozygous type A individual, what is the chance that their first child will have type AB blood?

50%

Multiple Alleles 1a: Blood type: There are three alleles for blood type A, B and O. A and B are both dominant to "O" and codominant to each other (meaning an AB person has AB blood type). If Matt has blood type 'O', and his wife Alex is heterozygous for blood type 'A', predict the blood types their children could inherit.Set-up and complete a Punnett square and match the correct genotype and their ratios from the list given.

50% AO: 50% OO

Incomplete dominance 1a: Petunia flower color: In petunias, purple flowers are PP, white flowers are P'P' and lavender flowers are PP' Predict the offspring of a cross between a lavender-flowered petunia and a white-floweredpetunia. Set-up and complete a Punnett square and match the correct genotype and their ratios from the list given.

50% PP': 50% P'P'

Incomplete dominance 1b: Petunia flower color: In petunias, purple flowers are PP, white flowers are P'P' and lavender flowers are PP' Predict the offspring of a cross between a lavender-flowered petunia and a white-floweredpetunia. Using the Punnett square in the last question, match the correct genotype and their ratios from the list given.

50% white; 50% lavender

What is the relationship among DNA, a gene, and a chromosome?

A chromosome contains hundreds of genes which are composed of DNA.

Recessive allele

A gene whose trait may be masked by another gene

Dominant allele

A gene whose trait that appears regardless of the second gene

Which describes a genotype homozygous dominant for a single trait?

AA

Blood typing is often used as evidence in paternity cases in court. In one case, the mother had blood type B and the child had blood type O. Which of the following blood types could the father NOT have?

AB

When two alleles for a single gene are fully expressed as in the AB blood type, this is called

Codominace

An individual having 2 identical alleles at a particular locus.

D. Homozygote

The law of independent assortment holds that

Each pair of alleles segregates independently of other pairs during gamete production.