Bio Exam 3
Chromosomes that are NOT involved in determining gender are known as
. autosomes.
Some daughter cells are described as clones. For this description to be appropriate, the daughter cells must
. contain a set of DNA that is identical to that of the parent cell.
A ________ is a chart that shows genetic relationships within a family over several generations.
. pedigree
If a plant has a total of 18 chromosomes, how many chromosomes would be present in each of its gametes?
9
The hereditary genetic material present in all living cells is
DNA
Because an individual with an XX genotype is a female, is an individual with an XO (no second sex chromosome) a male
No, because the Y chromosome contains the gene that makes an embryo male.
Which of the following genotypes represents a human male?
XY
An allele is
a version of a gene.
The processes of mitosis, meiosis, and binary fission all
are used to produce daughter cells.
If two different alleles for the same trait have an equal effect on the phenotype, the alleles are
codominant
Homologous chromosomes
consist of a maternal and paternal copy of each chromosome.
homologous chromosomes
contain the same genes in the same locations.
Most human genetic characters are
controlled by more than one gene
Along one side of a DNA molecule, the nucleotides are connected to each other by ________ bounds between ________
covalent; phosphate groups and sugar molecules
Two copies of the same gene on a single chromosome would indicate a(n) ________ had occurred.
duplication
Which of the following foods is MOST likely to contain haploid cells?
egg
Mendel's laws
explain how genes are inherited.
The X chromosome in humans is
found as a pair in females.
Mendel used ________ as his research organism to study patterns of genetic inheritance.
garden peas
The two strands of a DNA molecule are held together by ________ bonds between their base pairs.
hydrogen
Replication of DNA cannot begin until ________ bonds between ________ are broken.
hydrogen; complementary bases
A chestnut-colored (red-colored) horse is mated with a cremello (cream-colored) horse. Over a 10-year period, all of their offspring are palominos (gold-colored). This pattern of inheritance is best explained by
incomplete dominance.
What part of a nucleotide accounts for the genetic variation between individuals?
nitrogenous base
A female carrier of the X-linked recessive gene for red-green color blindness will display a phenotype of
normal color vision.
DNA replication
occurs before mitosis in the cell cycle.
If DNA polymerase did not have the ability to proofread, then DNA replication would
result in more mutations.
When examining the rapidly dividing cells of a fish embryo, a researcher notices a cell that seems to contain two nuclei. The middle of the cell is pinched inward. This cell must be in ________ of mitosis.
telophase
In humans, X-linked genetic diseases
tend to be expressed more in males than in females.
In Mendel's controlled mating experiments, the individuals produced by crossing two true-breeding parents are referred to as
the F1 generation.
If two parents are heterozygous for an autosomal recessive disease,
they are both considered genetic carriers for the disease.
In a karyotype of a male, which of the following would indicate an abnormality
three copies of chromosome 22
true/false; uracil is NOT a base found in DNA
true
On chromosomes within an individual, there are ________ alleles for a given gene found on ________ chromosomes.
two; homologous
During meiosis I, the chromosome number is reduced to haploid by separating
. one of each homologous chromosome pair into two different daughter cells.
Most inherited human genetic disorders are inherited as ________ alleles
. recessive
The difference between the alleles of a single gene is
. their DNA base sequences.
An actively dividing cell has six chromosomes. How many sister chromatids are present within this cell at the end of G2 phase?
12
A replicated chromosome consists of ________ sister chromatid(s).
2
Humans have ________ pairs of homologous chromosomes
23
What would promote a cell to move through the G2 checkpoint?
The genetic information has been duplicated.
Why did Mendel analyze thousands of plants while conducting his research?
The likelihood of seeing a clear pattern is higher with a larger data set.
the sequence of DNA differs among individuals within a species. This is the reason for
variations in phenotypes
The successful union of one male and one female gamete forms a new single cell known as a
zygote.
If a segment of double-stranded DNA has 20 percent adenine (A), how much of it is cytosine (C)?
30 percent
If a female who carries the X-linked recessive gene for hemophilia mates with a male who does not have hemophilia, what is the chance that their daughter will be a carrier of the gene
50 percent
Sickle-cell disease is an inherited chronic blood disease caused by an autosomal recessive allele. Suppose a man with sickle-cell disease fathers a child by a woman who is a carrier for sickle-cell disease. What are the chances their children will exhibit the disease?
50 percent
Among children with parents who are both carriers of Tay-Sachs, an autosomal recessive disorder, chances are that
50 percent will be carriers
Among children with parents who are both carriers of Tay-Sachs, an autosomal recessive disorder, chances are that
50 percent will be carriers.
If a genetic disorder is caused by a dominant allele, individuals with which of the following genotypes would be affected by the disorder?
AA and Aa
If one strand of DNA has the sequence CGATT, the sequence of the other strand of the same molecule will be
GCTAA.
What accurately describes crossing over?
Paternal chromosome 7 exchanges segments of DNA with maternal chromosome 7.
In humans, the "master sex switch" that determines whether an embryo will become a male is the
SRY gene.
What is the significance of crossing over?
The resulting gametes will have novel gene combinations compared to their parent cells' gene combinations.
The possible combinations of alleles in gametes ________ due to independent assortment and crossing over.
increases
A pool of cells is treated with a chemical that halts progress through the cell cycle. In which stage of the cell cycle would most cells be found?
interphase
The significance of specific base pairing in DNA is that
it provides a method for making exact copies of DNA.
When Mendel proposed the law of segregation, which of the following pieces of information did he NOT have
knowledge of the location of the alleles for flower color
DNA polymerase is used by the cell to
make copies of a DNA sequence.
Gametes are produced by meiosis rather than mitosis because
meiosis reduces the chromosome number so that zygotes produced will have one full genome
Gametes are produced by meiosis rather than mitosis because
meiosis reduces the chromosome number so that zygotes produced will have one full genome.
Mendel's laws of segregation and independent assortment both have their biological basis in events that take place during
meiosis.
Chromosomes are lined up at the middle of the cell during the ________ portion of cell division.
metaphase
A permanent change in the DNA base sequence due to an uncorrected mismatch error is called a(n)
mutation.
Once replication in a DNA molecule is complete, each new DNA molecule contains
one old strand and one new strand.
A Punnett square is used to
predict the genotypes and phenotypes of a genetic cross.
The sex of a human child is determined by the
presence or absence of the Y chromosome.
The outcome of meiosis is the
production of eggs and sperm.
