BIO457 GENETICS QUIZ 1

A nucleoside consists of a A) pentose sugar and a nitrogenous base. B) phosphate group and a nitrogenous base. C) pentose sugar and a phosphate group. D) pentose sugar, a phosphate group, and a nitrogenous base.

A

During which phase the chromosomes line up in the center of the cell? a. Metaphase b. Prometaphase c. Telophase d. Anaphase e. Prophase

A

The ABO blood groups in humans are an example of ________. a. multiple allele systems b. epistatic interactions c. gene dosage d. simple Mendelian inheritance e. incomplete dominance

A

The mutation responsible for sickle cell disease affects ___ in the hemoglobin gene. A) a single base pair B) a 13 base sequence C) the promoter region D) the terminator sequence

A

Two individuals who are heterozygous for a given trait are crossed. What will be thephenotypic ratio of their offspring? a. 75% will display the dominant trait, 25% will display the recessive trait b. 100% will display the recessive trait c. 100% will be heterozygous individuals d. 50% will display the dominant trait, 50% will display the recessive trait e. all of the above are possible

A

What is the main function of DNA? A. It stores information for protein synthesis B. It can be mutated C. It directs the process of protein synthesis D. It provides energy for the cell

A

Which of the following could NOT be used to describe a sex limited trait: A) This term refers to a trait controlled by a gene located on the X or Y chromosomes. B) This is a trait that occurs more frequently in one sex than another. C) This is an extreme example of a sex influenced trait. D) This trait is likely to be a secondary sex characteristic.

A

Which of the following is a small multicellular organism that is a useful genetic model? A) Caenorhabditis elegans B) Escherichia coli C) Paramecium D) Saccharomyces cerevisiae

A

Which of the following statements about a lethal allele is NOT correct? A) Lethal alleles are always recessive. B) Lethal alleles may have a late age of onset. C) Lethal alleles may be caused by mutations in essential genes. D) Lethal alleles may affect one individual differently than another.

A

Which of the following traits is NOT important for a model organism in genetics? A) long life cycle B) production of many offspring in a single mating C) well-known genetic history D) easily grown, reared, or maintained

A

____________ is (are) the organelle(s) found in eukaryotic cells that can contain ribosomes and process(es) proteins for distribution throughout the cell. A) Endoplasmic reticulum B) Centrioles C) Mitochondria D) Lysosomes

A

A _____________ is the location of specific gene on the _____________of a chromosome. A) genetic map; DNA molecule B) gene locus; genetic map C) nucleotide; DNA molecule D) gene position; map unit

B

A child born to a man and a woman who are both carriers of the mutant allele responsible for cystic fibrosis (CF) has a ___ chance of having the disease. A) 0% B) 25% C) 50% D) 100%

B

A semilethal allele is an example of which of the following extensions of Mendelian genetics? A) Incomplete dominance B) Incomplete penetrance C) Variable expressivity D) Overdominance

B

A trait that produces a 9:7 ratio in the F2 generation of a two-factor cross is most likely exhibiting which of the following? a. gene redundancy b. epistatic interactions c. overdominanced. multiple allele systems e. sex-limited inheritance

B

Down syndrome is a genetic disorder that occurs when individuals have an extra copy of chromosome 21. How might you confirm this condition in a newborn? A) Determine the DNA content of a cell (C-value). B) Examine the chromosome structure of the newborn. C) Determine the karyotype of cells in metaphase from the newborn. D) All of the above are necessary to establish that the newborn has Down syndrome.

B

Gregor Mendel is credited with discovering the principles of modern genetics. Which of the following was a contribution of Mendel to the founding principles of modern genetics? A) Used pea plants to map genes to locations on chromosomes. B) Studied the quantitative relationships of inheritance of traits to show that a factor is transmitted from parents to offspring in a predictable way. C) Determined that proteins are the products of genes. D) Carried out a detailed analysis of the molecular features of genes, including the regulation of gene expression.

B

If you have true breeding strains that differ only in a single character, how could you determine which trait for that character is dominant? A) Create another true breeding strain for another trait for that character. B) Create a monohybrid for that character and see which trait is present. C) Create a dihybrid and observe the phenotype. D) You cannot easily determine which trait is dominant.

B

In a Chi square test of a genetic cross there are n different phenotypic classes in the offspring.What is the value for the degrees of freedom for the test? a. n b. n - 1 c. n + 1 d. 2n e. none of the above

B

In general, most bacterial cells contain ___ chromosome(s). A) 0 B) 1 C) 2 D) 3

B

In soybeans, resistance to sudden death syndrome (SDS) is inherited as a dominant condition. In some cases, individuals that are not resistant to SDS (but whose parents were) can pass the trait on to their progeny. This is an example of which of the following? A) Overdominance B) Incomplete penetrance C) Incomplete dominance D) Variable expressivity

B

Laurie met her husband Jim at a support group for families dealing with PKU (phenylketonuria), a recessive genetic disorder. Laurie and Jim both have one sister who is affected with PKU and no other family history of the disorder. They come to you as a genetic counselor to ask what their risk is of having an affected child. What do you tell them? A) They must both be heterozygotes so their risk of having an affected child is ¼. B) They might both be heterozygotes so they should get tested to see if they carry the disease allele or not. C) Since neither one of them is affected, they are not at risk of having an affected child. D) You can't give them any firm answers because you don't know their genotypes.

B

Molecular genetics is the study of the A) transmission of genes from generation to generation. B) structure and function of genes. C) heredity of single--gene traits in groups of individuals. D) heredity of multigene traits in populations.

B

Ribosomes perform important functions in living cells related to cellular genetics. Which of the following statements about ribosomes is INCORRECT? A) All prokaryotic ribosomes are found in the cytosol. B) All eukaryotic ribosomes are found in the cytosol. C) Ribosomes in eukaryotic cells are found associated with the rough endoplasmic reticulum. D) All of the above are correct statements about ribosomes.

B

The DNA and histone proteins in a eukaryotic chromosome are compacted into structures called A) proteosoes. B) nucleosomes. C) telomeres. D) centromeres.

B

The recessive mutant allele that causes cystic fibrosis is much more frequent in Caucasians of eastern European descent than in other populations. Some scientists believe heterozygotes must have had a survival advantage during plagues such as cholera that occasionally swept through this population. What concept does this illustrate? A) Multiple alleles B) Overdominance C) Environmental influence D) Epistasis

B

What are the possible offspring from a type A mother and a type AB father? A) A, B, AB, and O B) A, B, and AB C) A and AB D) A only

B

What is the critical feature that distinguishes prokaryotes from eukaryotes? A) Prokaryotes have walled cells; eukaryotes do not. B) Eukaryotes have genetic material located inside nucleus surrounded by a nuclear membrane, whereas the genetic material of a prokaryote is not surrounded by a nuclear membrane. C) Prokaryotes are always smaller than eukaryotes. D) All prokaryotes are unicellular, whereas all eukaryotes are multicellular.

B

What ratio of phenotypes would you expect if you crossed a heterozygous Pea comb chicken to a heterozygous Rose comb chicken? A) 9 walnut: 3 rose: 3 pea: 1 single B) 1 walnut: 1 rose: 1 pea: 1 single C) 3 walnut: 1 single D) 3 rose: 1 pea

B

Which of the following is the best example of overdominance?A) Two lines of true breeding white parents produce purple flowered offspring. B) Two lines of true breeding tomatoes that are susceptible to verticillium wilt (a fungal infection) produce offspring that are resistant to verticillium wilt. C) Two true breeding lines, one tall and one short, produce offspring of medium height. D) Two true breeding lines, one tall and one short, produce all tall offspring.

B

You find a pink geranium in your flowerbed of red geraniums. Seeds from self fertilization of this plant produce 1/4 red plants, 1/2 pink plants, and 1/4 white plants. When considering the visible phenotype, which explanation is most likely? A) The soil in which the pink plant was growing was deficient in a critical nutrient. B) The pink plant had a new mutation, creating an allele to which the wild type "red" is incompletely dominant. C) The pink plant had a new mutation, creating an allele which is incompletely dominant to red. D) The pink plant had a new mutation, creating an allele which is codominant to "red".

B

A mutation in which most of the protein coding sequence of the gene is removed is most likely to be which type of allele? A) Lethal B) Dominant C) Loss of function D) Sex-limited

C

Consider the following cross: AaBBcc X AabbCc. What proportion of the offspring is expectedto be dominant for all three traits? Assume independent assortment. a. 1/2 b. 3/4 c. 3/8 d. 9/16 e. 9/32

C

During ________ phase of the cell cycle, the sister chromatids are formed. a. G1 phase b. G2 phase c. S phase d. Prophase e. Cytokinesis

C

During which phase the nuclear membrane reforms around the chromosomes? a. Metaphase b. Prometaphase c. Telophase d. Anaphase e. Prophase

C

I know that black coat color in mice is dominant to albino. Black mice get a higher price at the pet store so I am disappointed when I cross a black mouse with an albino mouse and get 6 albino and 2 black mice in the litter. I expected all black. What mistake did I make? A) I assumed that black alleles were more common than white. B) I assumed that white alleles were more common than black. C) I assumed that my black mouse was true-breeding. D) I assumed that my white mouse was true-breeding.

C

If an organism contains two identical alleles for the same trait, it is said to be a. cross-fertilized. b. heterozygous. c. homozygous. d. a hybrid. e. self-fertilized.

C

In a two-factor cross, if two individuals who are heterozygous for both traits are crossed withone another, what will be the phenotypic ratio of their offspring based on Mendel's work? a. 3:1 b. 1:2:1 c. 9:3:3:1 d. 15:1 e. 9:6:1

C

Neurofibromatosis is a condition in humans which is generally inherited in a dominant fashion. Assuming this disorder is 90% penetrant, what is the chance that a single child born to a father with neurofibromatosis and a mother known not to carry the mutation will have the disorder? A) 90% B) 50% C) 45% D) 5%

C

Organelles that possess their own genetic material include A) centrioles and the Golgi body. B) ribosomes and centrioles. C) mitochondria and chloroplasts. D) the endoplasmic reticulum.

C

Quantitative genetics is the study of A) transmission of genes from generation to generation. B) structure and function of genes at the chemical level. C) heredity of single--gene traits in groups of individuals. D) heredity of multigene traits in populations.

C

The Manx phenotype in cats is caused by a dominant allele that is lethal in the homozygousstate. If two Manx cats are crossed, what phenotypic ratio is expected in kittens that are born? a. all Manx b. 3 Manx : 1 normal c. 2 Manx : 1 normal d. 1 Manx : 1 normal e. all normal

C

The mutant gene responsible for Tay-Sachs disease is located on A) chromosome 3. B) chromosome 10. C) chromosome 15. D) the X chromosome.

C

The physical structure that is formed when two chromatids cross over is called a(n) _________________. a. synaptomenal complex b. bivalent c. chiasma d. karyotype

C

Which of the following events is LEAST likely to occur in a cross involving epistasis by both genes? A) A monohybrid has a different phenotype from either of the two parents. B) Two lines of true breeding white parents produce purple flowered offspring. C) A 9:3:3:1 ratio of F2 phenotypes is seen. D) All of these are likely to be seen in epistatic interactions.

C

Which of the following statements about model genetic organisms is correct? A) Prokaryotic organisms are not used as models because they typically do not reproduce sexually. B) Because humans are multicellular organisms, few genetic model species are single-celled organisms. C) Rapid generation time, small size, and large reproductive capacity all facilitate genetic studies. D) All of the above are important characteristics of genetic model organisms.

C

You set up a cross between true breeding wild type male fruit flies and true breeding female flies with a yellow body color. You notice in the F1 generation that half the flies, specifically all the males, have yellow body color while the females are wild type (gray). Which of the following explanations is the most likely? A) Some of your females had already mated with yellow males before you collected them. B) Some of your parental flies must have had a new mutation in their germ cells. C) The mutation which causes yellow body color is on the X chromosome. D) The mutation which causes yellow body color is on the Y chromosome.

C

A pattern-bald woman is married to a man with normal hair. Which of the following statementsabout their adult offspring is TRUE? a. All of their children are expected to be nonbald b. Half of their children of either sex are expected to be bald c. Half of their sons are expected to be bald, but none of their daughters d. All of their sons are expected to be bald; but none of their daughters e. All of their daughters are expected to be bald; but none of their sons

D

Chlamydomonas reinhardtii, Tetrahymena, Saccharomyces, and Paramecium are all A) model organisms that have contributed to our knowledge of genetics. B) unicellular. C) eukaryotes. D) All of the above are correct.

D

During which phase the sister chromatids separate and head towards opposite poles of the cell? a. Metaphase b. Prometaphase c. Telophase d. Anaphase e. Prophase

D

Eukaryotic cells differ from prokaryotic cells in that only the former contain A) ribosomes. B) cytoplasm. C) DNA. D) a nucleus.

D

Genetic distances between gene loci on genetic maps are usually given in A) nucleotides. B) centimeters C) amino acids D) map units

D

I do a chi square analysis of the offspring from my cross of a black mouse and albino mouse. If the black mouse was heterozygous I should have expected a 1:1 ratio, and I got 6 albino and 2 black mice. What is my chi square value? A) 0.25 B) 0.5 C) 1 D) 2

D

If you performed a dihybrid cross and found that your results were significantly different from the 9:3:3:1 ratio, what would you suspect? A) You miscounted your results. B) You had too small a sample size and need to repeat the experiment. C) You picked two genes that are linked and thus do not assort independently. D) You picked two genes that are linked and thus do not segregate during gamete formation.

D

In a group of fruit flies homozygous for an allele that causes a reduced number of thoracic bristles, you notice that the number of bristles varies from about half the normal number to only a few bristles. This is an example of which of the following? A) Incomplete dominance B) Overdominance C) Incomplete penetrance D) Variable expressivity

D

In a rare blood type referred to as the Bombay phenotype, individuals are unable to attach the A or B antigens to their red blood cells. Individuals that are homozygous recessive for gene "H" have the Bombay phenotype and their blood type is type "O" regardless of their ABO genotype. This is an example of what extension of Mendelian inheritance? A) Multiple alleles B) Overdominance C) Environmental influence D) Epistasis

D

In all types of cells, there is (are) at least ___ type(s) of RNA molecules. A) 0 B) 1 C) 2 D) 3

D

Mendel's single factor crosses led to which of the following rules of inheritance? a. concept of dominance b. law of segregation c. support for the particulate theory of inheritance d. all of the above

D

Pedigrees for human genetic traits are important because: A) Humans tend to have small numbers of offspring. B) Matings between humans cannot be established by experimenters. C) Knowledge about family history can help determine probabilities for individuals. D) All of the above. E) None of the above.

D

The most common allele in the population is called the _______. a. mutant allele b. essential allele c. dominant allele d. wild-type allele e. recessive allele

D

The one-gene- one-enzyme idea was replaced with ______________ as knowledge of gene structure improved. A) two-genes- one-enzyme B) the notion that genes do not encode enzymes C) one-gene- many-enzymes D) one-gene- one-polypeptide

D

The pea plant, Pisum sativum, was used by Mendel as a model organism for which of thefollowing reason(s): a. there were easily scorable traits such as flower color and seed shape. b. self-fertilization was possible. c. it was relatively easy to grow. d. all of the above are correct.

D

Which statement about nucleic acids is not correct? A. They are macromolecules B. They are organic molecules C. They are typically long, linear molecules D. None; all of these statements are correct

D

Women have two copies of the X chromosome, whereas men have an X and a Y chromosome. Sons always receive their X chromosome from their mother. Lesch- Nyhan syndrome is caused by a recessive mutation of a gene on the X chromosome that codes for hypoxanthine guanine phosphribosyl transferase, and that is a lethal gene. A woman heterozygous for the Lesch-Nyhan allele could have an affected A) son only. B) daughter and son. C) son, and grandson through this son. D) son, and grandson through her daughter.

D

You cross true breeding lizards that are either green or albino and discover that all the offspring are striped green and white. Which is the most likely result if you cross two striped lizards? A) All striped offspring. B) 3 striped: 1 albino C) 3 green: 1 albino D) 1 green: 2 striped: 1 albino E) None of the above are likely outcomes.

D

During which phase the chromosome start to condense? a. Metaphase b. Prometaphase c. Telophase d. Anaphase e. Prophase

E

Interphase of the cell cycle includes all of the following except __________. a. G1 phase b. G2 phase c. S phase d. G0 phase e. metaphase

E

Three populations of an organism, each with drastically different external markings, but still members of the same species, would be called _______. Select one: a. homologs b. mutants c. communities d. alleles e. morphs

E

Which of the following CANNOT possibly be the offspring of a man with type A blood and awoman with type B blood? a. a child with type A b. a child with type B c. a child with type AB d. a child with type O e. choose this answer if all of the above are possible

E

While studying for your genetics exam, a fellow student comments that the albino coat color gene in mice must be recessive. What mistake did they make? A) The gene that controls the coat color character comes in both dominant and recessive forms. B) The black coat color gene is actually dominant. C) The albino coat color gene is actually dominant. D) Coat color in mice cannot be easily described in dominant/recessive relationships.

A

You set up a monohybrid cross between true breeding round winged and true breeding oval winged insects. Your F1 offspring have round wings, and you collect the following numbers of F2: Round wings: 302; Oval wings: 86. Which of the following statements is NOT correct? A) The critical value for this chi square calculation is 7.815. B) The chi square value for this calculation is 1.663. C) Mendel's rules accurately predict the outcome of this cross. D) None of these; all are correct statements. E) A and B only

A