Exam 14: Mendel and the Gene Idea

Phenylketonuria (PKU)is a recessive human disorder in which an individual cannot appropriately metabolize a particular amino acid.The amino acid is not otherwise produced by humans.Therefore,the most efficient and effective treatment is which of the following?

Cystic fibrosis is an autosomal (not sex-linked)recessive trait.It mostly affects the lungs,and long term issues include frequent lung infections.A man and woman are healthy,and neither have cystic fibrosis,but they have one child out of four who has cystic fibrosis.What are the genotypes of the child's parents?

Use the following information to answer the questions below. Tay-Sachs disease is an inherited genetic disorder in which the gene sequence codes for an enzyme involved in lipid metabolism.Accumulation of lipids in the brain leads to seizures,blindness,loss of neural function,and early death.People can be carriers of this disease and only homozygotic offspring will die from this disorder. -This is an example of

Refer to the following information to answer the questions below. Humanoids on the newly explored planet Brin (in a hypothetical galaxy in ~50 years from the present)have a gene structure similar to our own,but many very different plants and animals. -One species of green plant,with frondlike leaves,a spine-coated stem,and purple cup-shaped flowers,is found to be self-pollinating.Which of the following is true of this species?

Use the following description and figure to answer the questions below. In a particular plant,leaf colour is controlled by gene locus D.Plants with at least one allele D have dark green leaves,and plants with the homozygous recessive dd genotype have light green leaves.A true-breeding dark-leaved plant is crossed with a light-leaved one,and the F₁ offspring is allowed to self-pollinate.The predicted outcome of the F₂ is diagrammed in the Punnett square shown below,where 1,2,3,and 4 represent the genotypes corresponding to each box within the square. -Which of the boxes marked 1-4 correspond to plants with dark leaves?

Refer to the following information to answer the questions below. Humanoids on the newly explored planet Brin (in a hypothetical galaxy in ~50 years from the present)have a gene structure similar to our own,but many very different plants and animals. -Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin.Patients are usually very tall and thin,with long spindly fingers,curvature of the spine,sometimes weakened arterial walls,and sometimes ocular problems,such as lens dislocation.Which of the following would you conclude about Marfan syndrome from this information?

Hydrangea plants of the same genotype are planted in a large flower garden.Some of the plants produce blue flowers and others pink flowers.This can be best explained by which of the following?

Use the following information to answer the questions below. Radish flowers may be red,purple,or white.A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring.The part of the radish we eat may be oval or long,with long being the dominant characteristic. -In the F₂ generation of the above cross,which of the following phenotypic ratios would be expected?

The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following?

Which of the following describes when two alleles separate from each other and end up in separate gametes?

Use the following information to answer the questions below. Drosophila (fruit flies)usually have long wings (+)but mutations in two different genes can result in bent wings (bt)or vestigial wings (vg). -If flies that are heterozygous for both the bent wing gene and the vestigial wing gene are mated,what is the probability of offspring with bent wings only?

Refer to the following information to answer the questions below. Gene S controls the sharpness of spines in a type of cactus.Cacti with the dominant allele,S,have sharp spines,whereas homozygous recessive ss cacti have dull spines.At the same time,a second gene,N,determines whether or not cacti have spines.Homozygous recessive nn cacti have no spines at all. -The relationship between genes S and N is an example of

The following questions refer to the pedigree chart in the figure below for a family,some of whose members exhibit the dominant trait,W.Affected individuals are indicated by a dark square or circle. -What is the likelihood that the progeny of IV-3 and IV-4 will have the trait?

Gray seed color in peas is dominant to white.Assume that Mendel conducted a series of experiments where plants with gray seeds were crossed among themselves,and the following progeny were produced: 302 gray and 98 white. (a)What is the most probable genotype of each parent? (b)Based on your answer in (a)above,what genotypic and phenotypic ratios are expected in these progeny? (Assume the following symbols: G = gray and g = white.)

Why did the F₁ offspring of Mendel's classic pea cross always look like one of the two parental varieties?

Black fur in mice (B)is dominant to brown fur (b).Short tails (T)are dominant to long tails (t).What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails?

Use the following information to answer the questions below. Labrador retrievers are black,brown,or yellow.In a cross of a black female with a brown male,results can be either all black puppies,1/2 black to 1/2 brown puppies,or 3/4 black to 1/4 yellow puppies. -These results indicate which of the following?

Use the following information to answer the questions below. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative.Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r,respectively.A third gene for the MN blood group has codominant alleles M and N. -If both children are of blood type M,which of the following is possible?

A scientist discovers a DNA-based test for one allele of a particular gene.This and only this allele,if homozygous,produces an effect that results in death at or about the time of birth.Of the following,which is the best use of this discovery?

Use the following information to answer the questions below. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative.Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r,respectively.A third gene for the MN blood group has codominant alleles M and N. -Which of the following is a possible partial genotype for the son?