Exam 5 (11 & 12)
Hair texture is an example of incomplete dominance. A person who is homozygous dominant HH has curly hair and they mate with a person who has straight hair (homozygous recessive hh). What percentage of their offspring will have straight hair?
0%
Hair texture is an example of incomplete dominance. A person who is homozygous dominant HH has curly hair and they mate with a person who has straight hair (homozygous recessive hh). What percentage of their offspring will have wavy hair?
100%
An organism has the following genotype: AaBBDDEEFF. How many different gametes could this organism produce?
2
A human female has how many pairs of homologous chromosomes?
23
How many chromosome pairs would you find in a karyotype from a human?
23
How many chromosomes do human sperm and egg cells have?
23
Cystic fibrosis is an autosomal recessive trait. A healthy young couple are both carriers of the cystic fibrosis trait. What is the chance that each of their future children will inherit this serious illness?
25%
Two normal individuals have a child who has cystic fibrosis, an autosomal recessive disease. What were the chances of this happening?
25%
The number of cells produced by meiosis is ____ and the number of cells produced by mitosis is two
4
Humans have ____ total nuclear chromosomes
46
A heart muscle cell of a person with Down syndrome has _____ chromosomes
47
Albinism is a recessively inherited condition. What is the probability that a child will be born with albinism if the child's mother is albino, the child's father has normal pigmentation, and the child's paternal grandmother was albino?
50%
If Maria and Tom are both carriers of a recessive disorder, such as cystic fibrosis, what is the chance their child will be a carrier too?
50%
In a cross between an individual with Huntington disease and an unaffected individual, what are the chances (percentage) their progeny will have the disease, considering that it is a dominant trait?
50%
What percentage of a man's chromosomes are found in a single sperm cell?
50%
If two individuals were heterozygous for freckles, which is a dominant trait, what percentage of their progeny would have freckles?
75%
A person with the AB blood type expresses which markers on their red blood cell surface? a. only A b. only B c. A and B d. they have no markers on their cell surface e. they have A, B, and O markers on their cell surface
A and B
What would be the genotype for a homozygous dominant for a single trait using the letter "a"?
AA
What would the genotype be for a symptomless carrier of an autosomal recessive disease?
Aa
Which represents a cross between 2 individuals heterozygous for a single trait? a. aa x aa b. aa x AA c. AA x aa d. Aa x Aa
Aa x Aa
True or False: a man with hemophilia can pass hemophilia on to his sons
False
Of all the people who have studied inheritance, the person who made the most lasting impression on the science of genetics is:
Gregor Mendel
Which of the following is a possible gamete for an individual with the genotype PPrr? a. PP b. Pr c. pr d. rr e. all of these are correct
Pr
If red flower color (R) is incompletely dominant to white flower color (r), then what is the genotype of pink flowers?
Rr
A pedigree chart reveals the presence of a disease trait in both a boy and his mother's father. This pattern would suggest ____ linked inheritance
X
Which human chromosome is passed on intact from father to son? ____ chromosome
Y
Which of the following chromosomes does NOT have a homologous partner in human males?
Y
Which of the following human chromosomes usually does NOT exchange DNA during meiosis?
Y chromosome
Which is an example of codominance? a. a homozygous black and homozygous white cow mate and produce a gray calf b. a homozygous black and homozygous white cow mate and produce three black calves and one white calf c. a homozygous black and homozygous white cow mate and produce three white calves and one black calf d. a homozygous black and homozygous white cow mate and produce a black and white spotted cow
a homozygous black and homozygous white cow mate and produce a black and white spotted cow
Human cells have: a. 23 pairs of chromosomes b. one pair of sex chromosomes c. at least one "X" chromosome d. forty six chromosomes e. all of the above
all of the above
Multifactorial inheritance includes what factors in addition to multiple genes interacting: a. diet b. environment c. general health d. amount of exercise e. all of these
all of these
What is the possible outcome of a mutation in terms of protein function? a. it's beneficial b. it's detrimental c. it has no effect d. all of these e. none of these
all of these
Two moths mate and produce bollworm caterpillars that are Bt-resistant and Bt-susceptible. Bt-resistant is an autosomal recessive trait. What are possible genotypes of the parents? a. RR, rr b. Rr, Rr c. RR, Rr d. none of these could be correct
b. Rr, Rr
The ability to roll your tongue into a U-shape is a recessively inherited trait. What is the possible parental combination that would produce a child with this trait? a. RR x Rr b. RR x rr c Rr x Rr d. rr x rr e. Both C and D are correct
both c and d are correct
Under what conditions would two parents have all color-blind children, both sons and daughters? a. the male parent is color-blind b. the female parent is a carrier c. the male parent is a carrier d. both parents are color-blind
both parents are color blind
Two healthy individuals have a child who has Huntington disease, an autosomal dominant disease. How did this happen?
both parents carried dominant gene but displayed the recessive gene
___________ of genetic disorders do not show traits of the disorder
carriers
ABO blood type inheritance is an example of
codominance
Homologous chromosomes: a. only undergo mitosis b. are replicated first c. contain genes for the same traits d. contain different but similar proteins
contain genes for the same traits
Most of the genetic variations produced by meiosis are due to the process of _______ ________
crossing over
The process by which homologous chromosomes exchange genetic material is _______ ___________
crossing over
Which of the following is unique to meiosis? a. nuclear membrane breaks down b. DNA organizes into chromosomes c. crossing over d. chromosomes align along the central plate of the cell
crossing over
What two processes occur during meiosis to aide in genetic diversity?
crossing over and independent assortment
Which of the following is not an x-linked trait? a. cystic fibrosis b. color-blindness c. duchenne muscular dystrophy d. hemophilia
cystic fibrosis
Which of the following is not a mechanism that contributes to diversity? a. random fertilization b. crossing over c. cytokinesis d. independent assortment
cytokinesis
2n is an abbreviation for
diploid
Fertilization results in the formation of a (diploid or haploid) zygote
diploid
According to Mendel, if an individual is heterozygous for a specific gene, the phenotype will be that of the ____________ trait alone
dominant
A carrier is someone who has one copy of a _________ allele and one copy of a __________ allele for a particular gene
dominant, recessive
3 copies of chromosome 21 on a karyotype would be what disorder
down syndrome
Nondisjunction or failure of chromosomes to separate can occur: a. during mitosis of sex cells b. during meiosis I or II of sperm or egg c. during meiosis I only of sperm or egg cells d. during meiosis II of sperm or egg cells e. during meiosis I or II in egg cells only
during meiosis I or II of sperm or egg cells
Two normal individuals have a child who has cystic fibrosis, an autosomal recessive disease. How did this happen?
each parent had one normal and one recessive allele or parents were carriers and passed recessive genes to the child
The process that merges the gametes from two parents is
fertilization
If a human zygote is aneuploid, it has: a. fewer than 46 chromosomes b. more than 46 chromosomes c. exactly 46 chromosomes d. fewer or more than 46 chromosomes e. fewer, more than, or exactly 46 chromosomes
fewer or more than 46 chromosomes
Sexual reproductive cells are called
gametes
The genetic makeup of an individual is a
genotype
Meiosis is a form of nuclear division that: a. is common to asexual life cycles b. does not require fertilization to follow c. prevents evolution d. halves the genetic material
halves the genetic material
A cell having one set of chromosomes is said to be
haploid
Gametes differ from other cells in the body because gametes are _______
haploid
If both alleles for a trait are different, it means that someone is
heterozygous
Crossing over occurs between ________ chromosomes
homologous
Chromosomes that look alike and carry the same sequence of genes for the same traits are __________ ____________
homologous chromosomes
A genetic cross of pure breed red-flowered snapdragons with pure breed white-flowered snapdragons resulted in F1-hyrbid offspring that all had pink flowers. When the F1 plants were self-pollinated, the resulting F2-generation plants had a phenotypic ratio of 1 red: 2 pink: 1 white. What is the most likely explanation? ________ ___________
incomplete dominance
The rate of aneuploidy (increases or decreases) as the age of the mother increases
increases
In humans, which process increases genetic diversity the most? a. mutations b. linkage c. recombination d. independent assortment e. gamete fusion
independent assortment
The principle wherein alleles of maternal and paternal genes are aligned in the cell during meiosis and separated independently of one another is the principle of __________ _______________
independent assortment
How does incomplete dominance affect the phenotype of a heterozygote? a. it results in a blend of the dominant and recessive phenotype b. it results in the expression of only the recessive phenotypes c. the dominant phenotype is still expressed, but only in patches d. the trait is not observed in the individual
it results in a blend of the dominant and recessive phenotype
Which of the following is a phenotype? a. long tongue b. Tt c. T d. Tthh e. Three of these are correct answers
long tongue
Why can you say that males determine the sex of their children? a. since males have two X chromosomes, whichever one is passed along to their offspring will determine the sex b. males will either contribute an X or a Y chromosome, whereas females will always contribute an X chromosome c. male chromosomes are inherited preferentially over female chromosomes d. Y chromosomes are dominant; X chromosomes are recessive e. all of these
males will either contribute an X or a Y chromosome, whereas females will always contribute an X chromosome
What cellular process is responsible for Mendel's law of segregation? a. mitosis b. mutation c. meiosis d. metaphase
meiosis
Which of the two meiotic divisions halves the chromosome number? (meiosis I or meiosis II)
meiosis I
Humans have 23 pairs of chromosomes. How many possible ways can these be sorted out during independent assortment? a. more than 8 million ways b. 46 ways c. 23 ways d. about 100 million ways e. 529 ways (23x23)
more than 8 million ways
Up to 40% of human height can be attributed to environmental rather than genetic factors; thus, we call height inheritance is: a. polygenic b. codominant c. recessive d. multifactorial e. dominant
multifactorial
Aneuploidy is the result of
nondisjunction
The universal donor to all blood types is
o negative
Meiosis I is completed in human females after puberty: a. once each month or every 28 days b. at the end of pregnancy c. prior to her birth d. every other month e. immediately following fertilization
once each month or every 28 days
In humans, a homologous chromosome pair consists of: a. one chromosome from mom and one from dad b. two chromosomes from mom and two from dad c. one chromosome from mom and two from dad d. 22 chromosomes from mom and 22 from dad
one chromosome from mom and one from dad
A ___________ chart is/are used to examine inheritance over several generations
pedigree
A physical trait is a
phenotype
The appearance of an organism is known as its
phenotype
Skin color is controlled by six separate genes, making the inheritance of skin color a good example of __________ inheritance
polygenic
Spina bifida is a disease that is caused by several different genes. This is an example of a __________ trait
polygenic
If a trait is not displayed in the phenotype, it is called
recessive
In humans, germ cells are produced in the ovaries and the
testes
Meiosis occurs in the _______ of the human male (anatomy)
testes
A trait that is exhibited in a varying range of degrees, such as height in humans, is an indication that the trait is due to: a. the contribution of several genes b. the presence of a single mutation c. more than one type of each chromosome d. over-expression of a single protein e. the loss of a segment of a single chromosome
the contribution of several genes
A phenotypically normal woman marries a man with Wilson disease, an autosomal recessive disorder. They have a son who has Wilson disease. If you need two copies of the recessive allele to be affected and the mother doesn't have the disease, how did the son get it?
the mother was a carrier
To express the recessive phenotype: a. it must be masked b. the organism must possess two alleles for the trait c. both of the organisms parents must also express the trait d. one of the organisms parents must also express the recessive trait
the organism must possess two alleles for the trait
Sickle-cell anemia is an autosomal recessive disorder. This means that people with the disorder inherit: a. the same recessive allele from both parents b. one dominant and one recessive allele c. codominant alleles d. sex-linked genes
the same recessive alleles from both parents
Which of the following is a difference between an autosome and a sex chromosome? a. an autosome has more DNA b. a sex chromosome is only present in the germ cells c. only autosomes can be diploid d. there are more autosomes than sex chromosomes in a cell
there are more autosomes than sex chromosomes in a cell
In a diploid organism: a. there are two copies of every gene, both inherited from the mother b. there are two copies of every gene, both inherited from the father c. there are two copies of every gene, one inherited from the mother and the other from the father d. there is one copy of every gene, randomly inherited from either mother or father e. there are only two alleles present in the entire population
there are two copies of every gene, one inherited from the mother and the other from the father
Which of the following is a genotype? a. T b. Tt c. long tongue d. Tthh e. three of these are correct answers
three of these are correct answers
Why is amniocentesis usually performed? a. to detect fetal abnormalities in chromosome number b. to detect problems with the placenta c. to determine the sex of the fetus d. to determine if gene therapy is indicated e. to assess the risk of premature birth
to detect fetal abnormalities in chromosome number
True or False: Females can be color blind
true
You have cystic fibrosis (CF), an autosomal recessive disease, if you have inherited: a. two normal CF alleles b. two normal and two defective CF alleles c. two normal and one defective CF alleles d. one normal and one defective CF alleles e. two defective CF alleles
two defective CF alleles
Human males have: a. only one sex chromosome, an X b. only one sex chromosome, a Y c. two sex chromosomes, both X's d. two sex chromosomes, both Y's e. two sex chromosomes, one X and one Y
two sex chromosomes, one X and one Y
In meiosis I, cytokinesis usually occurs after telophase one and produces (one or two) (diploid or haploid) cells
two, haploid
In human females meiosis II completes: a. before birth b. at puberty c. about every 28 days d. when one of her zygotes is fertilized
when one of her zygotes is fertilized
A sperm and ovum fuse to form a ________ during fertilization
zygote
The first diploid cell of a new organism is a
zygote
