AP Biology Chapter 15 Review

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1.	When Thomas Hunt Morgan crossed his red-eyed  generation flies to each other, the  generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?
a.	The gene involved is on the X chromosome.	
b.	The gene involved is on the Y chromosome.	
c.	The gene involved is on an autosome.	
d.	Other male-specific factors influence eye color in flies.	
e.	Other female-specific factors influence eye color in flies.	

____	2.	Morgan and his colleagues worked out a set of symbols to represent fly genotypes. Which of the following are representative?
a.	AaBb ´ AaBb	
b.	46, XY or 46, XX	
c.	vg+vgse+se ´ vgvgsese	
d.	+2 ´ +3	

____	3.	Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in Drosophila in which of these ways?
a.	There are four major functional classes of genes in Drosophila.	
b.	Drosophila genes cluster into four distinct groups of linked genes.	
c.	The overall number of genes in Drosophila is a multiple of four.	
d.	The entire Drosophila genome has approximately 400 map units.	
e.	Drosophila genes have, on average, four different alleles.	

____	4.	A man with Klinefelter syndrome (47, XXY) is expected to have any of the following EXCEPT
a.	lower sperm count.	
b.	possible breast enlargement.	
c.	increased testosterone.	
d.	long limbs.	
e.	female body characteristics.	

____	5.	A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype?
a.	Masculine characteristics such as facial hair	
b.	Enlarged genital structures	
c.	Excessive emotional instability	
d.	Normal female	
e.	Sterile female	

____	6.	Males are more often affected by sex-linked traits than females because
a.	males are hemizygous for the X chromosome.	
b.	male hormones such as testosterone often alter the effects of mutations on the X chromosome.	
c.	female hormones such as estrogen often compensate for the effects of mutations on the X.	
d.	X chromosomes in males generally have more mutations than X chromosomes in females.	
e.	mutations on the Y chromosome often worsen the effects of X-linked mutations.	

____	7.	What is the chromosomal system for determining sex in mammals?
a.	Haploid-diploid	
b.	X-0	
c.	X-X	
d.	X-Y	
e.	Z-W	

____	8.	What is the chromosomal system of sex determination in most species of ants and bees?
a.	Haploid-diploid	
b.	X-0	
c.	X-X	
d.	X-Y	
e.	Z-W	

____	9.	SRY is best described in which of the following ways?
a.	A gene region present on the Y chromosome that triggers male development	
b.	A gene present on the X chromosome that triggers female development	
c.	An autosomal gene that is required for the expression of genes on the Y chromosome	
d.	An autosomal gene that is required for the expression of genes on the X chromosome	
e.	Required for development, and males or females lacking the gene do not survive past early childhood	

____	10.	Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?
a.	 and 	
b.	 and 	
c.	 and 	
d.	 and 	
e.	 and 	

____	11.	Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the  males will have cinnabar eyes?
a.	0%	
b.	25%	
c.	50%	
d.	75%	
e.	100%	

____	12.	Calico cats are female because
a.	a male inherits only one of the two X-linked genes controlling hair color.	
b.	the males die during embryonic development.	
c.	the Y chromosome has a gene blocking orange coloration.	
d.	only females can have Barr bodies.	
e.	multiple crossovers on the Y chromosome prevent orange pigment production.	

____	13.	In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female?
a.	2:1 male to female	
b.	1:2 male to female	
c.	1:1 male to female	
d.	4:3 male to female	
e.	3:1 male to female	

Refer to the following information to answer the questions below.

A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was six feet tall, and both the woman's parents were of average height. Achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive.

____	14.	How many of their daughters might be expected to be color-blind dwarfs?
a.	All	
b.	None	
c.	Half	
d.	One out of four	
e.	Three out of four	

____	15.	What proportion of their sons would be color-blind and of normal height?
a.	All	
b.	None	
c.	Half	
d.	One out of four	
e.	Three out of four	

____	16.	They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?
a.	0	
b.	0.25	
c.	0.50	
d.	0.75	
e.	1.00	

____	17.	A Barr body is normally found in the nucleus of which kind of human cell?
a.	Unfertilized egg cells only	
b.	Sperm cells only	
c.	Somatic cells of a female only	
d.	Somatic cells of a male only	
e.	Both male and female somatic cells	

____	18.	Sex determination in mammals is due to the SRY region of the Y chromosome. An abnormality could allow which of the following to have a male phenotype?
a.	Turner syndrome, 45, X	
b.	Translocation of SRY to an autosome of a 46, XX individual	
c.	A person with too many X chromosomes	
d.	A person with one normal and one shortened (deleted) X	
e.	Down syndrome, 46, XX	

____	19.	Which of the following statements is true?
a.	The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.	
b.	The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%.	
c.	All of the traits that Mendel studied—seed color, pod shape, flower color, and others—are due to genes linked on the same chromosome.	
d.	Linked genes are found on different chromosomes.	
e.	Crossing over occurs during prophase II of meiosis.	

____	20.	How would one explain a testcross involving  dihybrid flies in which more parental-type offspring than recombinant-type offspring are produced?
a.	The two genes are linked.	
b.	The two genes are linked but on different chromosomes.	
c.	Recombination did not occur in the cell during meiosis.	
d.	The testcross was improperly performed.	
e.	Both of the characters are controlled by more than one gene.	

____	21.	New combinations of linked genes are due to which of the following?
a.	Nondisjunction	
b.	Crossing over	
c.	Independent assortment	
d.	Mixing of sperm and egg	
e.	Deletions	

____	22.	What does a frequency of recombination of 50% indicate?
a.	The two genes are likely to be located on different chromosomes.	
b.	All of the offspring have combinations of traits that match one of the two parents.	
c.	The genes are located on sex chromosomes.	
d.	Abnormal meiosis has occurred.	
e.	Independent assortment is hindered.	

____	23.	A 0.1% frequency of recombination is observed
a.	only in sex chromosomes.	
b.	only on genetic maps of viral chromosomes.	
c.	on unlinked chromosomes.	
d.	in any two genes on different chromosomes.	
e.	in genes located very close to one another on the same chromosome.	

____	24.	The following is a map of four genes on a chromosome:

Figure 15.1

Between which two genes would you expect the highest frequency of recombination?
a.	A and W	
b.	W and E	
c.	E and G	
d.	A and E	
e.	A and G	

____	25.	What is the reason that linked genes are inherited together?
a.	They are located close together on the same chromosome.	
b.	The number of genes in a cell is greater than the number of chromosomes.	
c.	Chromosomes are unbreakable.	
d.	Alleles are paired together during meiosis.	
e.	Genes align that way during metaphase I of meiosis.	

____	26.	What is the mechanism for the production of genetic recombinants?
a.	X inactivation	
b.	Methylation of cytosine	
c.	Crossing over and independent assortment	
d.	Nondisjunction	
e.	Deletions and duplications during meiosis	

Refer to Figure 15.2 to answer the following questions.

Figure 15.2

____	27.	In a series of mapping experiments, the recombination frequencies for four different linked genes of Drosophila were determined as shown in the figure. What is the order of these genes on a chromosome map?
a.	rb-cn-vg-b	
b.	vg-b-rb-cn	
c.	cn-rb-b-vg	
d.	b-rb-cn-vg	
e.	vg-cn-b-rb	

____	28.	Which of the following is a map of a chromosome that includes the positions of genes relative to visible chromosomal features, such as stained bands?
a.	Linkage map	
b.	Physical map	
c.	Recombination map	
d.	Cytogenetic map	
e.	Banded map	

____	29.	If a human interphase nucleus contains three Barr bodies, it can be assumed that the person
a.	has hemophilia.	
b.	is a male.	
c.	has four X chromosomes.	
d.	has Turner syndrome.	
e.	has Down syndrome.	

____	30.	If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis?
a.	All the gametes will be diploid.	
b.	Half of the gametes will be n + 1, and half will be n - 1.	
c.	1/4 of the gametes will be n + 1, one will be n - 1, and two will be n.	
d.	There will be three extra gametes.	
e.	Two of the four gametes will be haploid, and two will be diploid.	

____	31.	If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?
a.	n + 1; n + 1; n - 1; n - 1	
b.	n + 1; n - 1; n; n	
c.	n + 1; n - 1; n - 1; n - 1	
d.	n + 1; n + 1; n; n	
e.	n - 1; n - 1; n; n	

____	32.	A cell that has 2n + 1 chromosomes is
a.	trisomic.	
b.	monosomic.	
c.	euploid.	
d.	polyploid.	
e.	triploid.	

____	33.	One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?
a.	Deletion	
b.	Disjunction	
c.	Inversion	
d.	Translocation	
e.	Duplication	

____	34.	A nonreciprocal crossover causes which of the following products?
a.	Deletion only	
b.	Duplication only	
c.	Nondisjunction	
d.	Deletion and duplication	
e.	Duplication and nondisjunction	

____	35.	In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald?
a.	0%	
b.	25%	
c.	33%	
d.	50%	
e.	75%	

____	36.	Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual?
a.	47, +21	
b.	47, XXY	
c.	47, XXX	
d.	47, XYY	
e.	45, X	

____	37.	A phenotypically normal prospective couple seeks genetic counseling because the man knows that he has a translocation of a portion of his chromosome 4 that has been exchanged with a portion of his chromosome 12. Although he is normal because his translocation is balanced, he and his wife want to know the probability that his sperm will be abnormal. What is your prognosis regarding his sperm?
a.	1/4 will be normal, 1/4 with the translocation, 1/2 with duplications and deletions.	
b.	All will carry the same translocation as the father.	
c.	None will carry the translocation since abnormal sperm will die.	
d.	His sperm will be sterile and the couple might consider adoption.	
e.	1/2 will be normal and the rest with the father's translocation.	

____	38.	Abnormal chromosomes are frequent in malignant tumors. Errors such as translocations may place a gene in close proximity to different control regions. Which of the following might then occur to make the cancer worse?
a.	An increase in non-disjunction	
b.	Expression of inappropriate gene products	
c.	A decrease in mitotic frequency	
d.	Death of the cancer cells in the tumor	
e.	Sensitivity of the immune system	

____	39.	The frequency of Down syndrome in the human population is most closely correlated with which of the following?
a.	Frequency of new meiosis	
b.	Average of the ages of mother and father	
c.	Age of the mother	
d.	Age of the father	
e.	Exposure of pregnant women to environmental pollutants	

____	40.	An inversion in a human chromosome often results in no demonstrable phenotypic effect in the individual. What else may occur?
a.	There may be deletions later in life.	
b.	Some abnormal gametes may be formed.	
c.	There is an increased frequency of mutation.	
d.	All inverted chromosomes are deleted.	
e.	The individual is more likely to get cancer.	

____	41.	What is the source of the extra chromosome 21 in an individual with Down syndrome?
a.	Nondisjunction in the mother only	
b.	Nondisjunction in the father only	
c.	Duplication of the chromosome	
d.	Nondisjunction or translocation in either parent	
e.	It is impossible to detect with current technology	

____	42.	Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher?
a.	People in Latin or South America	
b.	The Inuit and other peoples in very cold habitats	
c.	People living in equatorial areas of the world	
d.	Very small population groups	
e.	No groups have such higher frequency	

____	43.	A couple has a child with Down syndrome when the mother is 39 years old at the time of delivery. Which is the most probable cause?
a.	The woman inherited this tendency from her parents.	
b.	One member of the couple carried a translocation.	
c.	One member of the couple underwent nondisjunction in somatic cell production.	
d.	One member of the couple underwent nondisjunction in gamete production.	

____	44.	At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?
a.	Early prophase	
b.	Late telophase	
c.	Anaphase	
d.	Late anaphase or early telophase	
e.	Late prophase or metaphase	

____	45.	Which of the following statements describes genomic imprinting?
a.	It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele.	
b.	It is greatest in females because of the larger maternal contribution of cytoplasm.	
c.	It may explain the transmission of Duchenne muscular dystrophy.	
d.	It involves an irreversible alteration in the DNA sequence of imprinted genes.	

____	46.	

Figure 15.4
The pedigree in Figure 15.4 shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely
a.	mitochondrial.	
b.	autosomal recessive.	
c.	sex-linked dominant.	
d.	sex-linked recessive.	
e.	autosomal dominant.	

____	47.	A gene is considered to be non-Mendelian in its inheritance pattern if it seems to "violate" Mendel's laws. Which of the following would then NOT be considered non-Mendelian?
a.	A gene whose expression varies depending on the gender of the transmitting parent	
b.	A gene derived solely from maternal inheritance	
c.	A gene transmitted via the cytoplasm or cytoplasmic structures	
d.	A gene transmitted to males from the maternal line and from fathers to daughters	
e.	A gene transmitted by a virus to egg-producing cells	

____	48.	Correns described that the inheritance of variegated color on the leaves of certain plants was determined by the maternal parent only. What phenomenon does this describe?
a.	Mitochondrial inheritance	
b.	Chloroplast inheritance	
c.	Genomic imprinting	
d.	Infectious inheritance	
e.	Sex-linkage	

____	49.	Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore in which body systems would you expect most mitochondrial gene mutations to be exhibited?
a.	The immune system and the blood	
b.	Excretory and respiratory systems	
c.	The skin and senses	
d.	Nervous and muscular systems	
e.	Circulation	

____	50.	A certain kind of snail can have a right-handed direction of shell coiling (D) or left handed coiling (d). If direction of coiling is due to a protein deposited by the mother in the egg cytoplasm, then a Dd egg-producing snail and a dd sperm-producing snail will have offspring of which genotype(s) and phenotype(s)?
a.	1/2 Dd : 1/2 dd; all right coiling	
b.	All Dd; all right coiling	
c.	1/2 Dd : 1/2 dd; half right and half left coiling	
d.	All Dd; all left coiling	
e.	All Dd; half right and half left coiling	

AP Biology Chapter 15 Review
Answer Section

MULTIPLE CHOICE

	1.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	2.	ANS:	C	PTS:	1	MSC:	Knowledge/Comprehension

	3.	ANS:	B	PTS:	1	MSC:	Knowledge/Comprehension

	4.	ANS:	C	PTS:	1	MSC:	Knowledge/Comprehension

	5.	ANS:	D	PTS:	1	MSC:	Application/Analysis	

	6.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	7.	ANS:	D	PTS:	1	MSC:	Knowledge/Comprehension

	8.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	9.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	10.	ANS:	E	PTS:	1	MSC:	Application/Analysis	

	11.	ANS:	E	PTS:	1	MSC:	Application/Analysis	

	12.	ANS:	A	PTS:	1	MSC:	Application/Analysis	

	13.	ANS:	A	PTS:	1	MSC:	Application/Analysis	

	14.	ANS:	B	PTS:	1	MSC:	Application/Analysis	

	15.	ANS:	C	PTS:	1	MSC:	Application/Analysis	

	16.	ANS:	E	PTS:	1	MSC:	Application/Analysis	

	17.	ANS:	C	PTS:	1	MSC:	Knowledge/Comprehension

	18.	ANS:	B	PTS:	1	MSC:	Application/Analysis	

	19.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	20.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	21.	ANS:	B	PTS:	1	MSC:	Knowledge/Comprehension

	22.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	23.	ANS:	E	PTS:	1	MSC:	Application/Analysis	

	24.	ANS:	E	PTS:	1	MSC:	Application/Analysis	

	25.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	26.	ANS:	C	PTS:	1	MSC:	Knowledge/Comprehension

	27.	ANS:	D	PTS:	1	MSC:	Application/Analysis	

	28.	ANS:	D	PTS:	1	MSC:	Knowledge/Comprehension

	29.	ANS:	C	PTS:	1	MSC:	Knowledge/Comprehension

	30.	ANS:	C	PTS:	1	MSC:	Application/Analysis	

	31.	ANS:	A	PTS:	1	MSC:	Application/Analysis	

	32.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	33.	ANS:	D	PTS:	1	MSC:	Knowledge/Comprehension

	34.	ANS:	D	PTS:	1	MSC:	Knowledge/Comprehension

	35.	ANS:	E	PTS:	1	MSC:	Application/Analysis	

	36.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	37.	ANS:	A	PTS:	1	MSC:	Synthesis/Evaluation	

	38.	ANS:	B	PTS:	1	MSC:	Synthesis/Evaluation	

	39.	ANS:	C	PTS:	1	MSC:	Knowledge/Comprehension

	40.	ANS:	B	PTS:	1	MSC:	Synthesis/Evaluation	

	41.	ANS:	D	PTS:	1	MSC:	Knowledge/Comprehension

	42.	ANS:	E	PTS:	1	MSC:	Knowledge/Comprehension

	43.	ANS:	D	PTS:	1	MSC:	Application/Analysis	

	44.	ANS:	E	PTS:	1	MSC:	Knowledge/Comprehension

	45.	ANS:	A	PTS:	1	MSC:	Knowledge/Comprehension

	46.	ANS:	A	PTS:	1	MSC:	Application/Analysis	

	47.	ANS:	D	PTS:	1	MSC:	Synthesis/Evaluation	

	48.	ANS:	B	PTS:	1	MSC:	Knowledge/Comprehension

	49.	ANS:	D	PTS:	1	MSC:	Synthesis/Evaluation	

	50.	ANS:	A	PTS:	1	MSC:	Application/Analysis