82 terms

Bio 111 Exam 4 Study Set

STUDY
PLAY

Terms in this set (...)

B
If an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can/must have which of the following?

A. up to more than, 18 different traits

B. at most, 2 alleles for that gene

C. up to 18 genes for that trait

D. up to 18 chromosomes with that gene
A
Which of the following descriptions correctly defines a genome?

A. the complete set of an organism's genes

B. a karyotype

C. the complete set of an organism's polypeptides

D. representation of a complete set of a cell's polypeptides
A
If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants?


A. Clone the plant asexually to produce an identical one.

B. Breed this plant with another plant with much weaker traits.

C. Backtrack through her previous experiments to obtain another plant with the same traits.

D. Force the plant to self-pollinate to obtain an identical one
B
In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?

A. length, centromere position, staining pattern, and DNA sequences

B. length, centromere position, staining pattern, and traits coded for by their genes

C. length and position of the centromere only

D. length, centromere position, and staining pattern only
A
The somatic cells of a privet shrub each contain 46 chromosomes. To be as different as they are from human cells, which have the same number of chromosomes, which of the following must be true?

A. Genes of privet chromosomes are significantly different from those in humans.

B. Genes on a particular privet chromosome, such as the X, must be on a different human chromosome, such as number 18.

C. Privet shrubs must be metabolically more like animals than like other shrubs.

D. Privet cells cannot reproduce sexually.
C
A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following?

A. It must be an animal
.
B. It must be human.

C. Its gametes must have 23 chromosomes.

D. It must be sexually reproducing.
A
Which of the following types of cells would be produced by meiosis?

A. a haploid animal cell

B. a diploid unicellular organism

C. a diploid plant cell

D. a diploid animal cell
D
Which of the following is an example of alternation of generations?


A. A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis.

B. A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote.

C. A diploid cell divides by mitosis to produce two diploid daughter cells, which then fuse to produce a tetraploid cell.

D. A diploid plant (sporophyte) produces, by meiosis, a spore that gives rise to a multicellular, haploid pollen grain (gametophyte).
D
For the following question(s), match the key event of meiosis with the stages listed below.

I. prophase I V. prophase II
II. metaphase I VI. metaphase II
III. anaphase I VII. anaphase II
IV. telophase I VIII. telophase II


Centromeres of sister chromatids disjoin and chromatids separate.

A. III

B. IV

C. V

D. VII
B
For the following question(s), match the key event of meiosis with the stages listed below.

I. prophase I V. prophase II
II. metaphase I VI. metaphase II
III. anaphase I VII. anaphase II
IV. telophase I VIII. telophase II

Homologous chromosomes are aligned at the equator of the spindle

A. I

B. II

C. IV

D. VI
B
When we see chiasmata under a microscope, that lets us know that which of the following processes has occurred?
?

A. anaphase II

B. prophase I

C. meiosis II

D. separation of homologs
B
To visualize and identify meiotic cells at metaphase I with a microscope, what would you look for?

A. individual chromosomes all at the cell's center

B. pairs of homologous chromosomes all aligned at the cell's center

C. sister chromatids of a replicated chromosome grouped at the poles

D. an uninterrupted spindle array
B
During mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesins. Such molecules must have which of the following properties?

A. They must persist throughout the cell cycle.

B. They must be removed before sister chromatids or homologous chromosomes can separate.

C. They must be intact for nuclear envelope re-formation.

D. They must be removed before meiosis can begin.
B
Which of the following events occurs in meiosis but not in mitosis?

A. chromosome replication

B. synapsis of chromosomes

C. production of daughter cells

D. condensation of chromatin
D
Which of the following happens during meiosis I?


A. Sister chromatids are separated.

B. Four daughter cells are formed.

C. The chromosome number per cell is conserved.

D Homologous chromosomes of a pair are separated from each other.
A
How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis?

A. They have half the number of chromosomes and one-fourth the amount of DNA.

B. They have the same number of chromosomes and half the amount of DNA.

C. They have half the amount of cytoplasm and twice the amount of DNA.

D. They have half the number of chromosomes and half the amount of DNA.
C
When homologous chromosomes cross over, what is the result?

A. Two sister chromatids get tangled, resulting in one altering the sequence of its DNA.

B. Two sister chromatids exchange identical pieces of DNA.

C. Specific proteins break the two strands of nonsister chromatids and re-join them.

D. Each of the four DNA strands of a homologous pair is broken, and the pieces are mixed.
B
Independent assortment of chromosomes during meiosis is a result of

A. the relatively small degree of homology shared by the X and Y chromosomes.

B. the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.

C. the random distribution of the sister chromatids to the two daughter cells during anaphase II.

D. the random nature of the fertilization of ova by sperm.
A
At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?


A. metaphase
B. telophase
C. anaphase
D. prophase
A (prophase I only)
For the following question(s), match the key event of meiosis with the stages listed below.

I. prophase I V. prophase II
II. metaphase I VI. metaphase II
III. anaphase I VII. anaphase II
IV. telophase I VIII. telophase II


Synaptonemal complexes form or are still present.


A. I only

B. I and IV only

C. I and VIII only

D. I, II, III, and IV only
1, 2, and 3
Use the figure and the following description to answer the questions below.

In a particular plant, leaf color 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 in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square.

D d
D 1 2
d 3 4

Which of the boxes marked 1-4 correspond(s) to plants with dark leaves?
2 and 3
In a particular plant, leaf color 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 in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square.

D d
D 1 2
d 3 4


Which of the boxes correspond(s) to plants with a heterozygous genotype?
1 and 4
In a particular plant, leaf color 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 in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square.

D d
D 1 2
d 3 4


Which of the plants will be true-breeding?
B
1) What do we mean when we use the terms monohybrid cross?

A) A monohybrid cross involves a single parent

B) monohybrid cross involves organisms that are heterozygous for only one character being studied.

C) A monohybrid cross is performed for one generation

D) A monohybrid cross results in a 9:3:3:1
B
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

A) There is considerable genetic variation in garden peas.

B) Traits are inherited in discrete units and are not the results of "blending."

C) Recessive genes occur more frequently in the F1 generation than do dominant ones.

D) Genes are composed of DNA.
B
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?

A) 4

B) 8

C) 16

D) 64
A
Which of the following statements about independent assortment and segregation is correct?

A) The law of independent assortment requires describing two or more genes relative to one another.

B) The law of segregation requires describing two or more genes relative to one another.

C) The law of independent assortment is accounted for by observations of prophase I.

D) The law of segregation is accounted for by anaphase of mitosis.
D
Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests

A) that the parents were true-breeding for contrasting traits.

B) incomplete dominance.

C) that a blending of traits has occurred.

D) that the parents were both heterozygous for a single trait.

E) that each offspring has the same alleles.
D
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism?

A) Hh

B) HhTt

C) T

D) HT
50%
When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype?
C
Mendel accounted for the observation that traits that had disappeared in the F1 generation reappeared in the F2 generation by proposing that _____.

A) new mutations were frequently generated in the F2 progeny, "reinventing" traits that had been lost in the F1

B) the mechanism controlling the appearance of traits was different between the F1 and the F2 plants

C) traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1

D) members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait
D
Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties?

A) No genes interacted to produce the parental phenotype.

B) Each allele affected phenotypic expression.

C) The traits blended together during fertilization.

D) One allele was dominant.
C
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?

A) 1/16

B) 3/8

C) 1/2

D) 9/16
D
In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?

A) 1

B) 1/2

C) 1/4

D) 0
D
Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort independently.

If 1,000 F2 offspring resulted from the cross, approximately how many of them would you expect to have red, terminal flowers?


A) 565

B) 250

C) 750

D) 190

E) 65
C
Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort independently.


Among the F2 offspring, what is the probability of plants with white axial flowers?



A) 9/16

B) 1/16

C) 3/16

D) 1/4
D
What can we observe in order to visualize Mendel's Law of Segregation?

A. sister chromatids separating during mitosis

B. the behavior of sex-linked genes

C. homologous chromosomes separating during meiosis II

D. the replication of DNA


E. homologous chromosomes separating during meiosis I
Wild type
What name is given to the most common phenotype in a natural population?
B
When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 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 Y chromosome.

B) The gene involved is on the X chromosome.

C) The gene involved is on an autosome, but only in males.

D) Other male-specific factors influence eye color in flies.
B
A white-eyed female Drosophila is crossed with a red-eyed male Drosophila. Which statement below correctly describes the results?

A. None of the females will have red eyes.

B. None of the females will have white eyes.

C. Twenty-five percent of the females will have white eyes.

D Fifty percent of the females will have red eyes.

E. Twenty-five percent of the females will have red eyes.
C
In humans, what determines the sex of offspring and why?

A) The male determines sex because the sperm can fertilize either a female egg or a male egg.

B) The female gamete determines sex because only the female gamete provides cytoplasm to the zygote.

C) The male gamete determines sex because each male gamete can contribute either an X or a Y chromosome.

D) The chromosome contribution from both parents determines sex because the offspring uses all the parents' chromosomes.

E) The female gamete determines sex because only the female gametes can have one of two functional sex chromosomes.
B
Which of the following is true of an X-linked gene, but not of a Y-linked gene?

A) It is only expressed in female offspring.

B) The gene is present in both males and females.

C) It is expressed in half of the cells of either male or female.

D) It does not segregate like other genes.

E) Sister chromatids separate during mitosis.
A
Which of the following statements correctly describes the meaning of the chromosome theory of inheritance as expressed in the early 20th century?

A. Mendelian genes are at specific loci on the chromosome and in turn segregate during meiosis.

B. Individuals inherit particular chromosomes attached to genes.

C. Natural selection acts on certain chromosome arrays rather than on genes.

D. No more than a single pair of chromosomes can be found in a healthy normal cell.

E. Homologous chromosomes give rise to some genes and crossover chromosomes to other genes.
D
Males are more often affected by sex-linked traits than females because _____.

A. male hormones such as testosterone often alter the effects of mutations on the X chromosome

B. female hormones such as estrogen often compensate for the effects of mutations on the X chromosome

C. X chromosomes in males generally have more mutations than X chromosomes in females

D. males are hemizygous for the X chromosome
C
SRY is best described as _____.

A) a gene present on the X chromosome that triggers female development

B) an autosomal gene that is required for the expression of genes on the Y chromosome

C) a gene region present on the Y chromosome that triggers male development

D) an autosomal gene that is required for the expression of genes on the X chromosome
D
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) XnXn and XnY

B) XNXN and XnY

C) XNXN and XNY

D) XNXn and XNY
100%
White eyes is a sex-linked recessive characteristic in fruit flies. If a female having white eyes is crossed with a wild-type male, what percentage of the F1 males will have white eyes?
B
Normally, only female cats have the tortoiseshell phenotype because
Normally, only female cats have the tortoiseshell phenotype because

A. the males die during embryonic development.

B. a male inherits only one allele of the X-linked gene controlling hair color.

C. only males can have Barr bodies.

D. the Y chromosome has a gene blocking orange coloration.
B
Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human X chromosome. The patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. They rarely live past their 20s.

A. How likely is it for a woman to have this condition?

B. One-half of the daughters of an affected man would have this condition.

C. Only if a woman is XXX could she have this condition.
Women can never have this condition.

D. One-fourth of the daughters of an affected father and a carrier mother could have this condition.

E. Very rarely: it is rare that an affected male would mate with a carrier female.
B
What event causes all female mammals to have one active X chromosome per cell instead of two?

A. activation of the BARR gene on one X chromosome, which then becomes inactive

B. activation of the XIST gene on the X chromosome that will become the Barr body

C. inactivation of the XIST gene on the X chromosome derived from the male parent

D.crossing over between the XIST gene on one X chromosome and a related gene on an autosome
None
A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was 6 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.


How many of their daughters might be expected to be color-blind dwarfs?
Half
A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was 6 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.


What proportion of their sons would be color-blind and of normal height?
100%
A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was 6 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.


They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?
A and G
the figure shows a map of four genes on a chromosome.

The figure shows a map of four genes on a chromosome:
A, W, E, and G from left to right. The distance between A and W is 5, between W and E is 3, and between E and G is 12.
A
Which of the following statements correctly describes linkage?

A. The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.

B. Linked genes are found on different chromosomes.

C. The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%.

D. All of the traits that Mendel studiedseed color, pod shape, flower color, and othersare due to genes linked on the same chromosome.
C
What does a frequency of recombination of 50% indicate?

A. What does a frequency of recombination of 50% indicate?

B. Independent assortment is hindered.

C. The two genes are likely to be located on different chromosomes.

D. The genes are located on sex chromosomes.

E. All of the offspring have combinations of traits that match one of the two parents.
E
One map unit is equivalent to which of the following values?

A. the recombination frequency between two genes assorting independently

B. the physical distance between two linked genes

C. 1 nanometer of distance between two genes

D. the distance between a pair of homologous chromosomes

E. 1% frequency of recombination between two genes
D
Which of the following events causes recombination between linked genes to occur?


A. Nonrecombinant chromosomes break and then re-join with one another.

B. When genes are linked they always "travel" together at anaphase.

C. Mutation on one homolog is different from that on the other homolog.

D. Crossovers between these genes result in chromosomal exchange.
E
What is the reason that closely linked genes are typically inherited together?

A. The number of genes in a cell is greater than the number of chromosomes.

B. Chromosomes are unbreakable.

C. Genes align that way during metaphase I of meiosis.

D. Alleles are paired together during meiosis.

E. The likelihood of a crossover event between these two genes is low
Translocation
One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?

duplication
transversion
deletion
translocation
inversion
47, +21
Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual?

45, X
47, +21
47, XXY
47, XYY
47, XXX
A
Down syndrome has a frequency in the U.S. population of ~1/830 live births. In which of the following groups would you expect this frequency to be significantly higher?

A. No groups have a significantly higher frequency.

B. people in Latin or South America

C. the Inuit and other peoples in very cold habitats

D. very small population groups

E. people living in equatorial areas of the world
A
Which of the following is known as a Philadelphia chromosome?

A. a human chromosome 22 that has had a specific translocation

B. a human chromosome 9 that is found only in one type of cancer

C. an imprinted chromosome that always comes from the mother

D. an animal chromosome found primarily in the mid-Atlantic area of the United States
A
A woman is found to have 47 chromosomes, including three X chromosomes. Which of the following describes her expected phenotype?

A. healthy female of slightly above-average height

B. enlarged genital structures

C. masculine characteristics such as facial hair

D. sterile female
B
Which of the following transmits genes from both parents to child, or from one generation of a family to another?

A.DNA

B.gametes

C.somatic cells

D.mitosis

E.nucleotides
E
In animals, fertilization is to zygote as meiosis is to which of the following?

A.mitosis

B.diploid


C.chromosome


D.replication

E.gamete
A
What allows sister chromatids to separate in which phase of meiosis?

A.release of cohesin along sister chromatid arms in anaphase II

B.crossing over of chromatids in prophase I

C.release of cohesin at centromeres in anaphase I

D.crossing over of homologs in prophase I
C
Imagine crossing a pea heterozygous at the loci for flower color (Pp) and seed color (Yy) with a second pea homozygous for flower color (pp) and seed color (yy). What genotypes of gametes will the first pea produce?

A.two gamete types: pp and Pp

B.two gamete types: pY and Py

C.four
gamete types: pY, py, PY, and Py


D.four gamete types: Pp, Yy, pp, PP
D
Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that

A.peas show easily observed variations in a number of characters, such as pea shape and flower color.


B.it is possible to control matings between different pea plants.

C.it is possible to obtain large numbers of progeny from any given cross.

D.peas have an unusually long generation time.

E.many of the observable characters that vary in pea plants are controlled by single genes.
C
A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates

A.the blending model of genetics.

B.true breeding.

C.dominance.

D.a dihybrid cross.

E.the mistakes made by Mendel.
C
Imagine a genetic counselor working with a couple who have just had a child who is suffering from Tay-Sachs disease. Neither parent has Tay-Sachs, nor does anyone in their families. Which of the following statements should this counselor make to this couple?

A."Because no one in either of your families has Tay-Sachs, you are not likely to have another baby with Tay-Sachs. You can safely have another child."


B."Because you have had one child with Tay-Sachs, you must each carry the allele. Any child you have has a 50% chance of having the disease."

C."Because you have had one child with Tay-Sachs, you must each carry the allele. Any child you have has a 25% chance of having the disease."

D."Because you have had one child with Tay-Sachs, you must both carry the allele. However, since the chance of having an affected child is 25%, you may safely have three more children without worrying about having another child with Tay-Sachs."E."You must both be tested to see who is a carrier of the Tay-Sachs allele."
B
Why did the improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics?

A.It revealed new and unanticipated features of Mendel's pea plant varieties.

B.It allowed the study of meiosis and mitosis, revealing parallels between behaviors of the Mendelian concept of the gene and the movement/pairing of chromosomes.


C.It allowed scientists to see the nucleotide sequence of DNA.


D.It led to the discovery of mitochondria.

E.It showed genes functioning to direct the formation of enzymes.
C
Morgan and his colleagues worked out a set of symbols to represent fly genotypes. Which of the following are representative?

A. AaBb x

B. 46 or 46w

C. w+ or w on X

D. +2 x +3
B
Imagine that Morgan had used a grasshopper (2n 24, and sex is determined as follows: male has X, and female has XX) to study sex linkage. Predict where the first mutant would have been discovered.

A.on the O chromosome of a male

B.on the X chromosome of a male

C.on the X chromosome of a female

D.on the Y chromosome of a male
B
Determination of sex in Drosophila is similar to that in humans. In some species of Drosophila, there are genes on the Y chromosome that do not occur on the X chromosome. Imagine that a mutation of one gene on the Y chromosome reduces the size by half of individuals with the mutation. Which of the following statements is accurate with regard to this situation?

A. This mutation is transmitted to all offspring of a male with the mutation.

B. This mutation is transmitted to all male but no female offspring of a male with the mutation.

C. This mutation is transmitted to all offspring of a female with the mutation.

D. This mutation is transmitted to all male but no female offspring of a female with the mutation.

E. This mutation is transmitted to all offspring of both males and females with the mutation.
D
Chromosomal rearrangements can occur after chromosomes break. Which of the following statements is most accurate with respect to alterations in chromosome structure?

A. Chromosomal rearrangements are more likely to occur in mammals than in other vertebrates.

B. Translocations and inversions are not deleterious because no genes are lost in the organism.

C. Chromosomal rearrangements are more likely to occur during mitosis than during meiosis.

D. An individual that is homozygous for a deletion of a certain gene is likely to be more damaged than one that is homozygous for a duplication of that same gene because loss of a function can be lethal.
C
Recall that in Drosophila, white eyes are due to an X-linked recessive allele (Xw). Describe a genetic cross that could result in white-eyed female Drosophila.

A.no possible cross

B.white-eyed females with red-eyed males

C.heterozygous red-eyed females with white-eyed males

D.heterozygous red-eyed females with red-eyed males
C
Which statement best describes the relationship between recombination frequency and the physical distance of genes on chromosomes?

A. There is no relationship. All genes have random recombination frequencies.

B. There is no relationship. All genes have the same, fixed recombination
frequencies.

C. The farther apart two genes are, the higher the recombination frequency

D. The closer together two genes are, the higher the recombination frequency
9%
What is the expected recombination frequency for a testcross between the black and cinnabar loci?
50% ( Even though subtracting 104.5 - 48.5 = 56 %, it is important to remember that the maximum RF (recombination frequency) for genes in the same chromosome = 50%.)
What is the expected recombination frequency for a testcross between the black and brown loci?
D
In tomatoes, a heterozygous plant with yellow flowers and red fruit is crossed with a recessive plant having white flowers and yellow fruit. The following distribution of offspring is observed:
yellow flowers, red fruit 42.5%
white flowers, yellow fruit 42.5%
yellow flowers, yellow fruit 7.5%
white flowers, red fruit 7.5%

What conclusion can be made regarding the loci for flower color and fruit color?
A.The loci may be on the same chromosome more than 50 map units apart, or they may be on separate chromosomes.

B.The loci are on separate chromosomes

.C.The loci are on the same chromosome, at an unknown distance from each other.

D.The loci are on the same chromosome 15 map units apart.
A
In tomatoes, a heterozygous plant with purple stems and normal leaves is crossed with a recessive plant having green stems and broad leaves. The following distribution of offspring is observed:

purple stems, normal leaves 25%
green stems, broad leaves 25%
purple stems, broad leaves 25%
green stems, normal leaves 25%

What conclusion can be made regarding the loci for stem color and leaf shape?

A.The loci may be on the same chromosome with equal or more than 50 map units apart, or they may be on separate chromosomes.

B.The loci are on separate chromosomes.

C.The loci are on the same chromosome, at an unknown distance from each other.

D.The loci are on the same chromosome 25 map units apart.