Biology I: Chapter 14 Review
Huntington's disease
Caused by a dominant allele and does not appear until late in a person's life?
recessive and located on the X chromosome
Colorblindness is more common in males than in females because the allele for colorblindness is
less soluble
Compared with normal hemoglobin, the hemoglobin of a person with sickle cell disease is
karyotype
A (n) _______can be used to determine whether a person has inherited the normal number of chromosomes.
X
A Barr body is an inactivated _____ chromosome.
haplotype
A _____ is a group of alleles found on the same chromosome that tend to be inherited all together.
mother
A boy who is colorblind inherited the disorder from his ____________________.
Is probably female
A cat that has spots of more than one color...
Turner's syndrome
A female with the disorder _____ inherits only one X chromosome.
two copies of every gene located on the X chromosome
A human female inherits
50% or 1/2
A man who is not colorblind and a woman who is a carrier of the disorder have a son. What is the probability that their son will be colorblind?
three
A person who has Down syndrome has ___ copies of chromosome 21
pedigree
A(n) _____ is a diagram that follows the inheritance of a single gene through several generations of a family.
2%
About how much of our DNA encodes the instructions for building proteins?
50%
According to the figure, what is the approximate probability that a human offspring will be female?
sticky ends
An advantage of using restriction enzymes such as EcoR1 is that it creates ____ that can match to complimentary base pairs.
without an X chromosome
Because the X chromosome contains genes that are vital for normal development, no baby has been born
all caused by nondisjunction
Down syndrome, Turner's syndrome, and Klinefelter's syndrome are
the male is heterozygous and the female is heterozygous
Examine the pedigree. The allele for the presence of a which forelock is dominant. Therefore, we can tell from the chart that in the couple labeled 2
75%
Examine the pedigree. The allele for the presence of a white forelock is dominant. What is the probability of the couple labeled 2 of having a child with a white forelock?
25 %
Examine the pedigree. The allele for the presence of a white forelock is dominant. What is the probability of the couple labeled 2 of having a child without a white forelock?
She has one allele for the disorder
For the pedigree, shaded symbols represent afflicted people. Males are squares; women are circles. If the trait is a sex-linked trait carried on the X chromosome, what is true about the mother represented by circle 1?
The fragments are separated using gel electrophoresis
How are DNA fragments separated for sequencing?
The chromosomes in each pair are similar in shape and size. They also contain the same genes, though no necessarily the same alleles of those genes.
How are the chromosomes that make up each numbered pair similar?
You can tell that nondisjunction occurred because the gametes have an abnormal number of chromosomes
How can you tell that nondisjunction occurred during the formation of the gametes in the figure?
The DNA sequence of the allele that causes cystic fibrosis has a deletion of three bases.
How is the DNA sequence of the allele that causes cystic fibrosis different from that of the normal allele?
46
How many chromosomes are shown in a normal human karyotype?
4
How many generations are shown in the pedigree?
one X chromosome
Human females produce egg cells that have
one X chromosome and one Y chromosome
Human males have
1/2 or 50%
If a couple has five boys, the probability that the next child will be a boy is
A, B, AB, or O
If a man with blood type A and a woman with blood type B produce an offspring, what might be the offspring's blood type?
A sperm that has 23 chromosomes fertilizes an egg that has 23 chromosomes resulting in 23 pairs of chromosomes (46 total) in the autosomal cells of the individual.
If human gametes have just 35 chromosomes, why does a human karyotype show 46?
The frequency of the sickle cell allele would probably decrease because the allele would no longer be beneficial in heterozygous individuals.
If malaria were eliminated from a certain area, how do you think the frequency of the sickle cell allele in that area would change?
some gametes may have an extra copy of some genes
If nondisjunction occurs during meiosis...
Homozyous recessive
If the allele for having a white forelock is dominant, family members without a white forelock are
more
If the gene for a recessive sex-linked trait was on the X chromosome, the trait would be _____ common in males than in females.
autosomes
In a human karyotype, 44 of the chromosomes are
female
In a pedigree, a circle represents a(an)
fold improperly
In cystic fibrosis, a change in a single gene causes the protein called CFTR to
When voltage is applied to the gel, one end of the the gel becomes positively charged. DNA fragments are negatively charged, so they move toward the positive end.
In gel electrophoresis, DNA fragments move across a gel. What causes them to move?
X and Y
In humans, sex is determined by the _____ chromosomes
father's gamete
In humans, the _____ determines the sex of the offspring.
the same phenotype
In humans, the inheritance of Rhesus (Rh) factor follow a pattern of simple dominance. This means that a heterozygous person has ______ as a person who has two dominant alleles.
four
In humans, there are three different alleles for blood type and two of these alleles are codominant, so there are ____ possible phenotypes
The chromosomes in each group are called homologous chromosomes
In the human karyotype, what term is used to describe the pair of chromosomes in each numbered group?
heterozygous
if a cat has both orange and black spots, it is _____ for the alleles on the X chromosome that code for spot color
What is illustrated in the picture
nondisjunction
sequence the DNA of every human gene
The Human Genome Project is an attempt to
Nondisjunction
The failure of homologous chromosomes to separate properly during meiosis
one whole X chromosome in a female cell
The formation of a Barr body inactivates
by finding overlapping regions between sequenced DNA fragments
The human genome was sequenced
Genetic Information Nondiscrimination Act (GINA)
The law that protects people from being discriminated against because of information learned in genetic tests is called
2
The pedigree chart shows ____ generations
recessive
The pedigree chart shows that some people can be carriers of the trait without being afflicted. The means the allele for the trait is
genomics
The study of whole genomes, including genes and their functions is known as _____.
Pp
The trait in the pedigree has two alleles: P (dominant) and p (recessive). The black symbols show the dominant phenotype, and the white symbols show the recessive phenotype. What is the gentoype of individual number 1?
mitosis
To make a karyotype, biologists take pictures of cells during _____ when they are condensed and easier to view.
may
Two parents who have Huntington disease _____ produce an offspring who does not have Huntington disease.
restriction enzymes
What can be used to cut DNA so it can be studied?
XX
What combinations of sex chromosomes represents a female?
promoters
What did scientists in the Human Genome Project look for in DNA to identify the locations of genes?
Drawing that shows the genetic relationships within a family
What is a pedigree chart?
cutting large DNA molecules into smaller pieces
What is the role of restriction enzymes in studying the human genome?
bioinformatics
What new field is described by the overlap area in the Venn diagram?
50 percent
What percentage of human sperm cells carry an X chromosome?
Discrimination based on genetic information about genetic disorders
What prevents insurance companies from discriminating against people based on information derived from genetic tests?
The goal of the Human Genome Project is to attempt to sequence all human DNA
What was the goal of the Human Genome Project
shortest
When DNA fragments are separated by gel electrophoresis, the ____fragments move fastest
nucleotide bases marked with dye
When sequencing DNA, replication stops when _____ are added to chains of DNA as the DNA is being synthesized.
The chromosomes in groups 1 through 22 are autosomes.
Which chromosomes in the karyotype are autosomes?
EcoRI and BamI
Which enzyme(s) in the figure would be best for making fragments with sticky ends?
One of the X chromosomes in a female cell
Which of the following form(s) a Barr body?
cutting the DNA into manageable pieces
Which was the first step in sequencing the human genome?
Male cells do not have two X chromosomes
Why are Barr bodies not found in male cells?
Males have just one X chromosome
Why are all X-linked alleles expressed in males, even if they are recessive?
The sex chromosomes are homologous because one sex chromosome is inherited from one parent, and the other is inherited from the other parent.
Why are the sex chromosomes considered homologous, even though they vary in size and appearance?
If human cells have a Y chromosome, the person is male regardless of how many X chromosomes are in the cells.
Why is a person who has Klinefelter's syndrome (XXY) a male, even though he has two X chromosomes in his cells?
Scientists can find how the human genome varies
Why is it helpful to sequence many human genomes, instead of just one?
similar to proteins found in other organisms.
More than forty percent of the proteins coded for in the human genome are
Klinefelter's syndrome
Nondisjunction can lead to the disorder called ____, in which a male has an extra X chromosome.
have some normal hemoglobin in their red blood cells
People who are heterozygous for sickle cell disease are generally healthy because they
two
People who have sickle cell disease inherited ___ copies of the sickle cell allele.
both the X chromosome and the Y chromosome
Sex-linked genes are located on
a change in one allele
Sickle cell disease is caused by a
