Exam 2
Unwinding, Complementary base pairing, and joining
3 steps of DNA replication
One duplication chromosome consisting of two sister chromatids.
A dyad consists of
A zygote with monosomy
A human egg with 22 chromosomes that is fertilized by a normal sperm will result in
Two chromosome with two sister chromatids each
A tetrad is composed of
A;T;G;C
According to Chargaff's rules, __________ always pairs with __________, and ___________ always pairs with __________.
diploidly
All but which one of following results from nondisjunction?
Alternative versions of the same trait
Alleles are
0
An individual with the karyotype 48, XYYY would have how many Barr bodies?
A cell with two or more nuclei
Cytokinesis usually, but not always, follows mitosis. If a cell undergoes mitosis and not cytokinesis, this would result in
The two resulting DNA molecules each have one new DNA strand and one old strand from the original DNA molecules.
DNA replication is called semiconservative because
2
During G1 stage of interphase, a diploid organism contains how many copies of each gene?
Genetic material is exchanged between non sister chromatids, resulting in new combinations of alleles.
During crossing over
Face opposite spindle poles
During meiosis 1, the homologous chromosomes of a tetrad
Chromosomes line up separately, with sister chromatids facing opposite spindle poles
During meiosis 2
The law of independent assortment
During meiosis, each pair of alleles on the homologous chromosomes sorts independently from all other pairs of alleles. This statement corresponds to
Interphase; S
During which stage of the cell cycle do the chromosomes duplicate?
Freckles
Example of phenotype
haploid, haploid, diploid
Following meiosis I, the daughter cells are ______; following meiosis II, the daughter cells are ______; and following mitosis, the daughter cells are _______.
45, XO
How is Turner Syndrome presented on a karotype?
there is DNA damage
If a cell stops at the G1 checkpoint, this is most likely due to what problem?
The trait is an autosomal dominant trait
If both parents express a particular trait, but their child does not, what does this indicate about the trait?
recessive trait
In a one-trait testcross, the phenotype that disappears in the F1 generation of a homozygous dominant and homozygous recessive cross is the
Meiosis produces haploid gametes and fertilization creates a diploid cell that divides by mitosis to produce a new individual.
In human life cycle
The number of chromosomes is cut in half in gametes.
It is essential that germ cells undergo meiosis so that
Crossing-over occurs in prophase of meiosis 1 but not in prophase of meiosis 2
One major difference between meiosis 1 and meiosis 2 is that
False, because both parents could carry the recessive allele.
Parents with the dominant phenotype cannot have offspring with the recessive phenotype.
May double back and base pair with itself ,whereas DNA does not
RNA differs from DNA because RNA
Nondisjunction
The failure of sister chromatids to separate during meiosis is called
All possible combinations of gametes based on a cross between the two parents.
The filled-in squares of a Punnett square represent
There was only one variety of pea available to Mendel.
The garden pea was a good model for Mendel's genetics experiments. Which of the following is not true regarding this model organism?
Adults who are diploid and produce haploid gametes; these gametes fuse to produce a diploid zygote which grows into an adult.
The human life cycle consists of
The possibility of non disjunction increases
The possibility of Down syndrome increases as the mother's age increases because
When the plant self-pollinates, all the offspring resemble the parent, and are homozygous for that gene
What does true-bleeding mean?
Centromere
What is the structure that holds together the two sister chromatids that form a chromosome?
Chromosome
What structure is formed by two sister chromatids being held together by a centromere?
During mitosis
When during the cell cycle are chromosomes visible?
Thymine
Which base is found in DNA , but not in RNA?
one factor must be dominant and one factor recessive in each individual
Which is NOT true according to Mendel's law and meiosis?
Interphase- shortest stage of the cell cycle
Which is not a correct association?
tRNA
Which of the following allows a cell to decipher the genetic codes?
pairing of homologous chromosomes
Which of the following does not occur twice during meiosis?
Turner Syndrome
Which of the following human syndromes is a monosomy?
Exhibit contact inhibition
Which of the following is not a characteristic of cancer cells?
Cause an organism to grow
Which of the following is not a function of meiosis?
Each gamete contains two genes for each trait.
Which of the following is not true with regard to the law of segregation?
prophase, metaphase, anaphase, telophase
Which of the following represents the phases of mitosis in their proper sequence?
Meiosis involves two divisions and produces four non identical daughter nuclei
Which of the following statements is correct?
Translation
Which process requires the participation of all three types of RNA
The regulation of the cell cycle is lost and uncontrolled cell division occurs
cancer occurs when
Translocation
when chromosome parts break off and attach to different chromosomes.