phenotype and genotype
If a plant is expressing a dominant phenotype, how could you determine if the plant is homozygous dominant or heterozygous? Cross with a another plant expressing the dominant phenotype Cross with a plant expressing the recessive phenotype
Cross with a plant expressing the recessive phenotype
The faulty gene (CFTR) associated with cystic fibrosis is carried by about how many Caucasians in the United States? 1 in 3000 1 in 300 1 in 30 1 in 30,000
1 in 30
If two parents are both affected by an autosomal recessive disorder, what percent of their children will also have the disorder? 50% 25% 75% 100%
100%
Because it is an autosomal recessive disorder, how many copies of the mutated CFTR allele do cystic fibrosis patients have? 1 4 3 2
2
How many alleles for the same gene control the inheritance of ABO blood types? 2 4 1 3
3
How many alleles for the same gene control the inheritance of ABO blood types? 4 3 2 1
3
If two heterozygous parents are both affected by an autosomal dominant disorder, then what percent of their children will be affected? 75 25 0 100
75
Two parents are both heterozygous for unattached earlobes and short fingers (EeSs). How many of the children would be expected to show both dominant traits, unattached ear lobes and short fingers?
9/16
One of the children in a family has freckles and long fingers and another child in the family has no freckles and short fingers. If the mother has a no freckles and long fingers, what is the genotype of the father with respect to these two traits? FFSs FfSS FFSS FfSs
FfSs
In a one-trait cross, if one parents is homozygous dominant and the other is homozygous recessive, what will the genotype of their offspring be?
Heterozygous
In a one-trait cross, if both parents are homozygous dominant, what will the genotype of their offspring be?
Homozygous dominant
______ alleles require two copies to be present in order to exert their effect.
Recessive
Which of the following are ways that a mutation for a genetic disorder can be passed to a child? Select all that apply. The mutation is present in all of a parent's cells. The mutation occurs during the formation of sperm or eggs. The child is exposed to another child with a genetic disorder. The child is exposed to radiation.
The mutation is present in all of a parent's cells. The mutation occurs during the formation of sperm or eggs.
What is a gene locus?
The position of a gene on a chromosome.
EeSs x EESS
Two-trait cross between one individual who is heterozygous for both traits and one individual who is homozygous for both traits
The gene responsible for determining male gender is located on the X chromosome. Y chromosome. autosome 15. autosome 1.
Y chromosome.
What are all the genotypic possibilities for the gametes of a parent that is homozygous recessive for two genes (aabb)? Ab, aB, ab ab aabb AB, Ab, aB, ab
ab
Alternate forms of a gene are called ______
allele
Tay-Sachs disease is NOT sex-linked and so therefore is termed a(n) _____________ recessive disorder.
autosomal
How is sickle-cell disease inherited? autosomal dominant sex-linked incomplete dominant autosomal recessive
autosomal recessive
Even though it affects lysosomes, which are present in nearly every cell, Tay-Sachs disease mainly affects the brain. red blood cells. lungs. liver.
brain
Cystic fibrosis is a relatively common autosomal recessive disease that causes thick mucus to build up mainly in which two areas of the body? lymphatic vessels inner ears bronchial tubes pancreatic ducts large intestine
bronchial tubes pancreatic ducts
All combinations of alleles are possible in the gametes because the ______ align independently during meiosis. chromosomes cells microtubules phenotypes
chromosomes
An AaHh x AaHh cross is an example of a one-trait cross. homozygous cross. monohybrid cross. dihybrid cross.
dihybrid cross
A __________ allele masks the expression of an alternate form of that same gene.
dominant
The ____________ allele of a gene is represented with an uppercase letter.
dominant
True or false: More females than males have X-linked recessive disorders. True False
false
True or false: People who are heterozygous for the sickle-cell mutation show no signs or symptoms of the disease.
false
Marfan syndrome is an autosomal dominant disorder in which the gene coding for what specific protein is mutated? fibrillin collagen hemoglobin huntingtin
fibrillin
Which X-linked recessive disorder is the most common cause of inherited mental disability? color blindness fragile X syndrome Duchenne muscular dystrophy hemophilia
fragile X syndrome
The specific genes or combination of alleles for a trait is called an individual's
genotype.
If a parent shows a dominant phenotype for a trait and has an offspring with the recessive phenotype, the genotype of the parent has to be homozygous dominant. homozygous recessive. heterozygous.
heterozygous
Although males with Duchenne muscular dystrophy usually die before they are fathers, the recessive allele remains in the population due to females that are homozygous dominant. autosomal carriers. heterozygous carriers. homozygous recessive.
heterozygous carriers.
The most effective medical (drug) treatment for sickle cell disease is uric acid. antibiotics. a clotting inhibitor. hydroxyurea.
hydroxyurea.
Select all common symptoms or signs of sickle cell disease. jaundice anemia caved-in chest joint pain easily broken bones
jaundice anemia joint pain
The position of a gene on a chromosome is called its _____
locus
Because the allele for red-green color blindness is carried on the X chromosome and is recessive, the disorder is much more common in heterozygotes. males. females. twins.
males
Men will inherit X-linked dominant disorders from their father. their mother. both parents.
mother
Several inheritance patterns differ from one trait crosses, in which one gene effects one trait. If multiple genes govern a trait it is said to follow an inheritance pattern called _______. If one gene affects many traits, it follows an inheritance pattern called _______. incomplete dominance; polygenic inheritance multiple-allele; pleiotropy codominance; pleiotropy
multiple-allele; pleiotropy
Huntington disease affects
nervous sytem
A father of blood type AB cannot be the father of a child with which blood type? AB O B A
o
In a one-trait cross, the inheritance of ______ set(s) of alleles is being examined, and in two-trait crosses, the inheritance of ________ set(s) of alleles is being examined.
one, two
Select all of the following that are autosomal dominant disorders. osteogenesis imperfecta sickle-cell disease Huntington disease Marfan syndrome
osteogenesis imperfecta Huntington disease Marfan syndrome
The physical appearance of a trait in an individual is the ______________, although in some cases traits are not easily observable.
phenotype
When one gene affects multiple, seemingly unrelated, traits it is called
pleiotropy
When one gene affects multiple, seemingly unrelated, traits it is called _________
pleiotropy
Traits that are governed by multiple sets of alleles that result in a continuous variation of phenotypes (bell-shaped curve) are called ______ traits. generational polygenic codominant multiple allele
polygenic
A diagram that lists sperm genotypes on one side and egg genotypes on the other side to predict the genotypes of offspring is called a _____ square.
punnet
Because it is _______________ -linked and recessive, color blindness affects more males than females.
sex
A girl is homozygous for long fingers (ss) and homozygous for no freckles (ff). Determine the possible alleles present in her eggs. ssff only SF only SF or sF sf only SSFF or SsFF
sf only
A male with a genotype XbY is red-green color blind because color blindness shows incomplete dominance. he inherited a dominant allele from his mother. the Y chromosome does not carry an allele for that trait. the Y chromosome carries a recessive allele for color blindness.
the Y chromosome does not carry an allele for that trait.
Because it is an autosomal recessive disease, in order for a person to have sickle-cell disease, they must inherit a recessive allele from each parent. both parents must be affected. at least one parent must be affected. the person must be homozygous dominant.
they must inherit a recessive allele from each parent.
In the offspring of a cross between two heterozygotes, ______ phenotype(s) are possible when the trait displays incomplete dominance, and ______ phenotype(s) are possible when the trait displays simple dominance. three; one two; one three; three three; two one; two
three; two
True or false: X-linked recessive disorders are often passed from grandfather to grandson. True False
true
Which of the following represents a monohybrid cross? Aa x Aa aa x aa AA x AA AA x aa
Aa x Aa
A male without freckles (recessive trait) mates with a freckled female (dominant trait). They have two children, one has freckles and the other does not. What is the genotype of the mother? FF Ff ff
Ff
An Ff x Ff cross is an example of a
Monohybrid cross
Osteogenesis imperfecta affects
bones
Marfan syndrome affects
connective tissue, CV system, eye
x-linked dominant disorders can be inherited from -only the father -either or both parents -only the mother
either or both parents
The recessive allele for having no freckles could be represented as f. F.
f
A WwSs genotype is called dihybrid because the individual is ______ for two traits. homozygous heterozygous
heterozygous
True or false: Fragile X syndrome is the most common proven cause of autism. True False
true
Which of the following are classified as human sex chromosomes? autosome 15 Y X autosome 1
x, y
Sickle-cell disease is caused by a mutation that produces an abnormal form of ______, which causes red blood cells to be sickle-shaped. lysosomal enzyme hemoglobin fibrillin CFTR
Hb
How many traits are being considered in a monohybrid cross? 4 8 1 2
1
How many copies of a damaged allele must be present for a recessive genetic disease to be expressed? 2 3 1 4
2
What are all the genotypic possibilities for the gametes of a parent that is heterozygous for two genes (AaBb)?
AB,Ab,aB,ab
How many copies of a mutated allele need to be inherited for an autosomal dominant genetic disorder to be displayed?
1
How many copies of a damaged allele must be present for a recessive genetic disease to be expressed? 4 2 1 3
2
If there are four possible alleles for a specific gene, how many different alleles does each individual inherit? 1 2 8 4
2
If there are four possible alleles for a specific gene, how many different alleles does each individual inherit? 8 2 1 4
2
If there are three possible alleles for a specific gene, how many different possible genotypes exist in the population for this gene (assume none are lethal)? 4 6 10 8
6
Which of these is an example of alleles? -A gene on a chromosome coding for an antibody and a gene on the same chromosome coding for an enzyme -A gene on a chromosome coding for a structural protein and a gene on a non-homologous chromosome coding for a different structural protein -A gene on a chromosome coding for brown eyes and a gene at the same locus of a homologue coding for blue eyes
A gene on a chromosome coding for brown eyes and a gene at the same locus of a homologue coding for blue eyes
In a Punnett square what is written horizontally above the columns and vertically to the left of the rows? -Parent phenotypes -Offspring genotypes -Alleles of gametes
Alleles of gametes
An X-linked disorder that causes muscle degeneration due to the absence of a protein involved in calcium release is hemophilia. Duchenne muscular dystrophy. Huntington disease. sickle-cell disease.
Duchenne muscular dystrophy.
SS x Ss
One-trait cross between one homozygous individual and one heterozygous individual
EE x ee
One-trait cross between two homozygous individuals
EEWw x eeww
Two-trait cross between one individual who is homozygous for one trait and heterozygous for the other, and an individual who is homozygous recessive for both traits
An individual's genotype is the specific ______ an individual has for a trait.
genes
Select all correct descriptions of autosomal dominant disorders. heterozygotes have an affected phenotype affected children typically have unaffected parents both males and females are affected with equal frequency more males are affected than females two unaffected parents will not have children with an affected phenotype
heterozygotes have an affected phenotype both males and females are affected with equal frequency two unaffected parents will not have children with an affected phenotype
A child with wavy hair has a parent with straight hair and a parent with very curly hair. What genetic phenomenon explains this? multiple alleles polygenic inheritance incomplete dominance codominance
incomplete dominance
A genetic system in which a heterozygous individual displays a phenotype intermediate between that of an individual homozygotic for either allele is called _______________ _______________.
incomplete dominance
Both Huntington disease and fragile X syndrome exhibit anticipation, in which the number of repeats in a gene can ______ in each generation. decrease increase stabilize cross over
increase
A defect in the production of a connective tissue protein causes________ syndrome, which causes long limbs and fingers, a caved-in chest, and dislocated lenses of the eye.
marfan
Marfan syndrome, in which a mutation in a gene leads to a weakened aorta, poor eyesight, and long limbs, is an example of pleiotropy. continuous variation. a polygenic trait. codominance.
pliotropy
Color blindness is an X-linked ______ disorder. dominant pleiotropic codominant recessive
recessive
A young African American patient who is anemic, has yellow sclera of the eye, and is complaining about pain in the joints most likely has which genetic disease? Marfan syndrome hemophilia sickle cell disease osteogenesis imperfecta
sickle cell disease
The best definition of phenotype is -specific genes that determine a person's physiology. -easily observable traits determined by genes. -the physical manifestation of a genetic trait. -all the genetic information in an organism's genome.
the physical manifestation of a genetic trait.
True or false: If both parents are affected by an autosomal recessive disorder, all children will be affected.
true
Humans normally inherit _________ allele(s) for each gene.
two, 2
Humans normally inherit ____________ allele(s) of each gene
two, 2
For each gene, an individual inherits ______ allele(s) with ______ being contained in the sperm and ______ being contained in the egg. one; one; one two; one; one three; one; two four; two; two
two; one; one