Review

An organism has 24 chromosomes in most of its cells. How many chromosomes are in the organism's egg cells?

12

In recombinant DNA technology, a piece of DNA from one organism is joined to the DNA of another organism. What may result from further work with this altered DNA?

35 000 to 40 000

What is the percent chance of producing blue-feathered offspring when crossing a blue-feathered hen with a white-feathered rooster?

50

A male shark has 40 chromosomes in each of its sex cells. How many chromosomes would be present in a normal body cell of a shark?

80

Which is a step in the process of producing transgenic bacteria?

A human gene is inserted into a bacterial plasmid.

The inheritance of short wings in Drosophila fruit flies is an x-linked, recessive trait. Which would most likely result if a short-winged female mates with a long-winged male?

All females will be long-winged, and all males will be short-winged.

Which of the following is an example of codominance in genetic traits?

An orange cat and a black cat produce an orange-and-black kitten.

When gametes are produced from a parent cell during normal meiosis, which of the following describes the number of chromosomes in each resulting cell?

Each resulting cell has the same number of chromosomes as the parent cell.

Body cells of fruit flies contain only 8 chromosomes, compared to human cells that contain 46. Scientists used studies of fruit flies to discover how egg and sperm cells (gametes) are formed. What did they observe?

Egg cells from the female had 4 chromosomes.

Given that a maple tree has sprouted from a cut maple stump, which inference about the new plant is most likely correct?

It has the same DNA as its parent.

The pedigree below shows the occurrence of red-green colorblindness in four generations of a family. Use the information in the pedigree to answer the following question(s). Which of these best explains the pattern of inheritance for the colorblindness trait?

The allele for colorblindness is carried on the X-chromosome.

A substitution of thymine with adenine in one DNA codon causes a particular disorder. Which statement explains how the change in DNA leads to this disorder?

The point mutation causes a different amino acid to be added to the hemoglobin protein.

A pedigree is a diagram that traces the inheritance of a trait through a family. Which of the following patterns is typical in a pedigree for an autosomal dominant trait?

The trait appears in every generation.

Which statement best describes a cloned population?

There are usually no variations in genotypes.

Which of the following is the primary advantage of sexual reproduction when compared to asexual reproduction?

There is greater genetic variety in offspring.

Which of the following statements correctly describes meiosis?

Which of the following statements correctly describes meiosis?

One kind of chromosomal mutation can occur during meiosis when a pair of chromosomes that carry genes for the same trait fail to separate. Which of these represents the sex chromosomes of a male organism when this type of chromosomal mutation has occurred?

XXY

Which of the following best describes the inheritance of a sex-linked trait?

a dominant allele carried by females that affects only males

Assume that brown eyes (B) are dominant over tan eyes (b) in guinea pigs. When a brown-eyed male is mated with a tan-eyed female, 50% of the litter has brown eyes and 50% has tan eyes. What is the genotype of the female guinea pig?

bb

Which of the following would be an example of gene therapy technology?

development of a nasal spray that contains copies of the normal gene that is defective in persons with cystic fibrosis

Which of these processes occurs during sexual reproduction but not during asexual reproduction?

meiosis

The original strand of DNA looks like this ACGTCTCGA, the mutated strand looks like this ACGTTCGA. What type of mutation is this?

nucleotide base deletion

Sickle cell anemia is a disease that affects red blood cells. This is the result of a mutation called a ___.

nucleotide base substitution

An inherited metabolic disorder called phenylketonuria (PKU) can result in serious problems in infancy. The chance that two parents who are heterozygous will have a child with PKU is 25%. Which of the following terms best applies to the inheritance pattern for PKU?

recessive

Which of the following terms best applies to the inheritance pattern for PKU?

recessive

Which of these would most likely cause a mutation?

the insertion of a nucleotide into DNA