Uark ShadwicK Bio Exam 3 Chapter Questions
A normal male marries a color-blind woman. What percent of their female children will be color-blind?
0%
In guinea pigs, B = black, b = brown, S = short hair, s = long hair. A heterozygous black, short-haired animal reproduces with a brown, long-haired animal. What is the expected phenotypic ratio of the offspring?
1 black short hair, 1 black long hair, 1 brown short hair, 1 brown long hair
A cross is made between two parents with genotypes AaBB and aabb. If there are 32 offspring, how many of them would be expected to exhibit both dominant characteristics?
16
What are the chances that two individuals with wavy hair (an incomplete trait) will have a curly-haired child? Curly hair and straight hair exhibit incomplete dominance.
25%
What will the genotypic ratio be of a monohybrid cross of two individuals who are both heterozygous for a trait? Use the link in the instructions to an online Punnet square frame.
25% homozygous dominant, 50% heterozygous, 25% homozygous recessive
Color-blindness is inherited as an X-linked recessive trait. A male who is color-blind marries a heterozygous woman. What percent of their total children will be color-blind?
50%
The four o'clock flower is an example of incomplete dominance: R = red, r = white, and Rr = pink. If two hybrids are crossed, what are the chances that an offspring will have pink flowers?
50%
If a woman is a carrier for the color-blind recessive allele and her husband has normal vision, what are their chances that a son will be color-blind?
50%, since the mother is only a carrier.
In guinea pigs, B = black, b = brown, S = short hair, s = long hair. Two heterozygous individuals reproduce. The expected results are
9 black short hair, 3 black long hair, 3 brown short hair, 1 brown long hair.
In humans, aniridia, a type of blindness, is due to a dominant allele A. Migraine headaches are due to another dominant allele M. If a man who suffers from both conditions (AaMm) marries a woman who suffers from both (AaMm), what are the chances of an offspring expressing both traits.
9/16
Which piece of evidence did Darwin observe during his 5-year journey aboard the HMS Beagle?
A South American species of finch is most likely the ancestor of the Galápagos Island finches.
When only a few individuals survive unfavorable times, thereby losing the majority of genotypes in the next generation, it is called
A bottleneck effect.
During allopatric speciation
A geographic separation occurs between subpopulations.
In peas, yellow is dominant over green in seeds. With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous?
A green-seeded plant
The location of a gene on a chromosome is called
A locus
A pheasant breeder starts with two birds in the P generation, one of which is AA and the other is aa. If he takes two of the birds from the F1 generation and breeds them together, what can he expect in his F2 offspring?
AA, Aa, aa
Some plants fail to produce chlorophyll, due to a recessive trait. If we locate a pea plant that is heterozygous for this trait, self-pollinate it, and harvest the seeds, what are the likely phenotypes of the resulting offspring?
About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross
A color-blind (recessive trait) woman will pass the allele to
All her children
Alternative forms of a gene that influence the same trait and are found at the same location in homologous chromosomes are called
Alleles
The model of speciation that requires some time with geographic barriers between two populations, allowing evolution of reproductive isolation, is
Allopatric speciation.
What are Alleles? A. genes for different traits, such as hair color and eye color B. alternative forms of a gene for a single trait, such as blue eyes or brown eyes C. the locations of genes on a chromosome D. recessive forms of a kind of characteristic carried by genes
Alternative forms of a gene for a single trait, such as blue eyes or brown eyes
Which is NOT true according to Mendel's law of segregation? A. Each individual contains two alleles for each trait. B. An individual can have either both dominant alleles, both recessive alleles, or a dominant and recessive allele. C. Alleles separate from each other during gamete formation. D. Each gamete contains one copy of each allele. E. Fertilization restores the presence of two alleles.
An individual can have either both dominant alleles, both recessive alleles, or a dominant and recessive allele.
The fin of a tuna and the flipper of a dolphin are
Analogous structures.
A new classification by domains separates prokaryotes into
Archaea and Bacteria.
What is the evolutionary relationship among archaea, bacteria, and eukarya?
Archaea and eukarya share nucleic acid similarities, so eukarya split off from archaea.
Mendel's law of segregation implies that the two members of an allele pair A. are distributed to separate gametes. B. are distributed to the same gamete. C. are assorted dependently. D. are segregated pairwise.
Are distributed to separate gametes.
In peacock spiders, a male displays before a female. If the male is of the wrong species then the female will reject him because he does not do the correct courtship display or have the correct color patterns. This is an example of a ___________________ isolating mechanism.
Behavioral
Consider the above phylogenetic tree. Which of the following species are most closely related? A. chimpanzee and rhesus monkey B. gibbon and capuchin C. rhesus monkey and capuchin D. galago and green monkey
Chimpanzee and rhesus monkey
You have two true-breeding rose bushes, one with red flowers and one with white flowers. A cross between these two roses yields a bush with white flowers that have red splotches. What condition does this demonstrate?
Codominance
Which of these is a correct description of a form of horizontal gene transfer in bacteria?
Conjugation occurs when a cell passes DNA to another cell by means of a sex pilus.
One bacterial cell passes DNA to a second cell through a sex pilus in the process of
Conjugation.
Fruit flies of the species Drosophila melanogaster are an important model organism for eukaryotic genetics. The genes for olive body color and purple eye color are on the same chromosome. Consider an organism with the chromosomes in the diagram above. What process is capable of producing a gamete with the alleles "pO"?
Crossing over
Which refers to the loss of a portion of a chromosome?
Deletion
Which type of natural selection increases the frequency of one extreme phenotype?
Directional
If a chromosomal segment appears more than once in the same chromosome, it is termed a(n)
Duplication
Which refers to the addition of a repeat segment of a chromosome?
Duplication
Hydrangeas are a flowering plant with large showy blooms. When a plant is grown in aluminum-rich soil it has blue flowers. If the same plant is transplanted into soil that is lacking aluminum, the flowers produced will be pink. This is an example of
Environmental effects
In a Mendelian monohybrid cross involving two homozygous genotypes, the ____ generation is always completely heterozygous.
F1
A man with AB blood type can have a child with type O. True or False
False
All cases of Down syndrome are caused by trisomy of chromosome 21. True or False
False
Which evidence for evolution uses impressions of plants and animals pressed into sedimentary rock?
Fossil Record
Movement of alleles between populations such as by the migration of breeding individuals is called
Gene Flow
A random alteration in the sequence of DNA nucleotides that provides a new variant of the gene is
Gene mutation
A population of mice live in a grassy area near a stream. Some individuals have alleles that give them white fur while other have alleles for brown fur. One day the stream floods killing a higher percentage of mice wtih the brown alleles basically at random. This changes the genetic makeup of the population and a higher percentage of the next generation of mice have white fur. This is an example of
Genetic Drift
The _____ indicates the gene combination of an individual.
Genotype
Consider the above phylogenetic tree. Which of the following species are most closely related? A. gibbon and green monkey B. gibbon and capuchin C. green monkey and capuchin D. galago and capuchin
Gibson and Green Monkey
Red-legged frogs and Bullfrogs can interbreed in the lab. However, Red-legged frogs only breed in fast-moving streams and Bullfrogs only breed in ponds. This is an example of a _______________ isolating mechanism.
Habitat
Which of the following sex-linked diseases is characterized by the absence of a clotting factor? A. hemophilia B. color-blindness C. Duchenne muscular dystrophy D. None of the answer choices is true.
Hemophilia
In a testcross, an organism with a dominant phenotype, but unknown genotype is crossed with which of the following to establish its genotype? A. homozygous dominant B. heterozygous C. homozygous recessive D. heterozygous dominant
Homozygous recessive
Consider the above phylogenetic tree. Which of the following species are most closely related? A. human and green monkey B. gibbon and capuchin C. green monkey and capuchin D. galago and green monkey
Human and green monkey
Which of the following is an example of the blending of phenotypes? A. codominance B. polygenic inheritance C. simple Mendelian inheritance D. incomplete dominance
Incomplete Dominance
You have two true-breeding rose bushes, one with red flowers and one with white flowers. A cross between these two roses yields a bush with pink flowers. What condition does this demonstrate?
Incomplete Dominance
If a chromosomal segment is turned around 180°, the chromosomal mutation is termed a(n)
Inversion
Which of the following is NOT correct concerning the law of independent assortment? A. It is based upon the process of meiosis. B. Each pair of factors separates independently. C. All possible combinations of factors can occur in the gametes. D. It follows the observation that all maternal chromosomes end up in the egg.
It follows the observation that all maternal chromosomes end up in the egg.
Which of the following is true about genetic drift? A. It may lead to an allele becoming fixed in a population when its alternative allele is lost from the population. B. It increases the number of heterozygotes in a population. C. It increases the level of rare alleles in a population. D. It reduces the chances of mutation in a population.
It may lead to an allele becoming fixed in a population when its alternative allele is lost from the population.
An individual who has an XXY combination of sex chromosomes is said to have _____ syndrome.
Klinefelter
Considering that males can have Klinefelter (XXY) syndrome, XYY, and normal XY chromosomal combinations, and females can have Turner (XO) syndrome, poly-X (XXX, XXXX), and normal XX combinations, it is obvious that
Maleness results from the minimal presence of one Y chromosome.
Two species of peas are visited by the same species of bee. Each species of pea has its stamens positioned to place pollen on different parts of the bee's body. Upon visiting other flowers, the pollen from the bee can only get on the female parts of the same species. This is an example of a ___________________ isolating mechanism.
Mechanical
Consider the above diagram. The eggs and the resulting gametes would be the result of nondisjunction in
Meiosis 1
Which refers to the loss of a complete chromosome?
Monosomy
A population of mice live in a grassy area near a stream. Some individuals have alleles that give them white fir while others have alleles for brown fur. One day a mouse is born in which an allele for brown fur has change and causes the mouse to be tan. This is an example of
Mutation
A population of mice live in a grassy area near a stream. Some individuals have alleles that give them white fur while others have alleles for brown fur. A family of hawks move in and nest nearby. The hawks catch the white mice at a higher rate because those mice do not blend into the surroundings so well. This changes the genetic makeup of the population and a higher percentage of the next generation of mice have brown fur. This is an example of _______.
Natural Selection
If the Hardy-Weinberg equilibrium is met, what is the net effect?
No evolution because the alleles in the population remain the same
When homologous chromosomes fail to separate during meiosis, this is termed
Nondisjunction.
Inbreeding within a population is an example of
Nonrandom mating.
Which of the following kinds of molecules is thought to have been absent from the primitive reducing atmosphere? A. water vapor (H2O) B. methane (CH4) C. hydrogen (H2) D. oxygen (O2)
Oxygen
Cold weather can change the ______ of a Himalayan rabbit.
Phenotype
Which of the following represents the physical characteristics of the individual? A. phenotype B. genotype C. alleles D. dominance
Phenotype
What genetic disorder is associated with the lack of an enzyme necessary for the normal metabolism of the amino acid phenylalanine?
Phenylketonuria (PKU)
Microbiology is the study of microbes. These include all but which of the following? A. Archaea B. Bacteria C. viruses D. plants
Plants
Traits that are controlled by several sets or pairs of alleles, such as skin color and height in humans, are the result of what form of inheritance?
Polygenic
When two or more genes with multiple alleles affect the same trait in an additive fashion, it is termed
Polygenic inheritance
During sympatric speciation
Reproductive isolation between certain subpopulations occurs.
Which genetic disorder is associated with an irregular shape of the red blood cells?
Sickle Cell Disease
What general feature is necessary to consider an organism a microbe?
Small enough that a microscope is required to see them
Which of these conditions is NOT among the requirements of the Hardy-Weinberg equilibrium?
Small population with genetic drift
Considering the various theories, the energy used in forming organic molecules in the primitive atmosphere could have come from all EXCEPT
Sound
Which type of natural selection occurs when an intermediate phenotype is favored?
Stabilizing selection
In Arkansas, the gray tree frog breeds in March, while the closely related species Harpers frog breeds at the end of May. This is an example of a ___________________ isolating mechanism.
Temporal
According to Lamarck, which variable would have the greatest influence on the evolution of an organism?
The Environment
Cheetahs are very genetically similar, meaning there is not a lot of genetic diversity in their gene pool. It appears that at least 2 times in the last 10,000 years cheetah populations crashed to very low numbers. The present day low genetic diversity is due to _____________.
The bottleneck effect.
Lamarck's proposal of the inheritance of acquired characteristics included the idea that
The continual stretching of giraffe's necks to reach leaves led to longer necks in offspring.
Which statement is NOT true about the founder effect?
The founder effect occurs when a population is subjected to near extinction and then recovers, so that only a few alleles are left in survivors.
Lizards on a small island are more likely to have to mate with close relatives. The form of microevolution is
The founder effect.
What evidence would NOT be studied by a biogeographer?
The genetic makeup of organisms that evolved in separate but similar conditions
Miller's laboratory experiments showed that
The primitive gases can react together to produce small organic molecules.
Disruptive selection is described in the text with the case of British land snails. In the grassy fields, the light-banded snails escape bird predators. In the darker forest, the dark snails survive and the light-banded snails are eaten. As long as the snails continue to cruise across the British landscape mating at the same season and having access to each other, why doesn't this "disruptive selection" eventually lead to two separate species?
There is no reproductive isolation to prevent gene flow.
When he arrived at the Galápagos Islands, Darwin did not observe the amazing tool-using "woodpecker finch" that can modify twigs to pry out grubs. Because there are no true woodpeckers on the Galápagos Islands, this behavior allows this finch to exploit an untapped food source. However, not all members of this species exhibit this behavior, which is probably learned from watching other finches. Therefore, which of the following is NOT true? A. Young isolated at hatching will not know how to do this. B. It is probably not "hardwired" in the brain as a behavior passed on genetically. C. There must be a great advantage to reaching this food source for this learned behavior to be repeated by most descendants each generation. D. This "learned" behavior will not lead to evolutionary change in the woodpecker population.
This "learned" behavior will not lead to evolutionary change in the woodpecker population.
Which type of genetic exchange occurs among bacteria in which DNA is carried into a bacterial cell by means of a virus?
Transduction
Bacterial cells pick up free pieces of DNA from the medium pieces that were released from dead bacteria in a process called
Transformation
Which refers to the movement of a piece of one chromosome to another nonhomologous chromosome?
Translocation
A person who has an extra copy of a chromosome is said to have
Trisomy.
A person with an XO genotype is classified as having
Turner syndrome.
In which kind of cross could you expect to find ratios of 1:1:1:1 among the offspring?
Two-trait test cross
Which of the following conditions does NOT contribute to evolution? A. mutations B. gene flow C. genetic drift D. unchanging environmental conditions
Unchanging environmental conditions
Anatomical features that are fully developed and functional in one group of organisms but reduced and functionless in a similar group are termed
Vestigial
A woman who can roll her tongue (presumably dominant) is married to a man who cannot. Two of their four children can roll their tongues and two cannot. If A = roll tongue and a = cannot roll tongue, then what is the genotype of the parents?
Woman Aa; Man Aa
Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis. However, it is possible to assert that _____ resulted in nondisjunction in ____.
XYY; spermatogenesis
Genes on the ___ chromosome determine if the sex of a child will be male or female.
Y
Common fruit flies, Drosophila melanogaster, have been used as model organisms to study inheritance in animals for many years. Flies with the yellow body phenotype make no melanin. Look at the image above to see diagrams representing the "wild-type" and "yellow body" flies. In an experiment, Karen crossed a true-breeding line of wild-type flies with yellow body flies. All the offspring of those crosses were wild-type. Then Karen crossed the offspring with each other. She got 328 yellow body flies and 1014 wild-type flies. What is the probably inheritance pattern for the yellow body allele?
Yellow body is recessive to wild-type