Quiz 9 Flashcards
What is the function of centromeres (kinetochores) on chromosome?
initiate DNA replication
site of rRNA synthesis
site of spindle fiber (microtubule) attachment
site of spindle fiber (microtubule) attachment
What is the function of spindle fibers (microtubules)?
they form the metaphase plate
to pull one sister chromatid of each chromosome to opposite sides of the cell
they form part of the cell membrane during cytokinesis
to pull one sister chromatid of each chromosome to opposite sides of the cell
Suppose a somatic cell at G1 phase of interphase had 20 chromosomes with 10 picograms of DNA. Predict the number of chromosomes and DNA content in the G2 phase.
20 chromosomes and 10 picograms
20 chromosomes and 20 picograms
40 chromosomes and 10 picograms
40 chromosomes and 20 picograms
20 chromosomes and 20 picograms
In a comparison of your SOMATIC chromosomes to those of your dad’s, which of the following statements is most accurate?
all of your chromosomes are exactly like your dad’s
all of your chromosomes are partly your dad’s and partly your mom’s
none of your chromosomes are exactly like your dad’s
half your chromosomes are like your dad’s and the other half are like your mom’s
half your chromosomes are like your dad’s and the other half are like your mom’s
How does bacterial DNA differ from the DNA in eukaryotes
it is circular in bacteria and linear in eukaryotes
bacteria use thymine instead of uracil
bacterial chromosomes are “v-shaped”, whereas eukaryotic chromosomes are “x-shaped”.
bacterial and eukaryotic DNA is identical
it is circular in bacteria and linear in eukaryote
In order to complete meiosis and form four gametes from a single starting cell, there must be two cell divisions (meiosis I and meiosis II). Which of the following occurs in meiosis II?
chromatids separate
crossing over occurs
tetrads form
DNA content doubles
chromatids separate
There is a species of mouse that holds the record for number of chromosomes. Each of its gametes has 48 chromosomes. Therefore, how many chromosomes would be found in one of its liver cells?
24
48
96
192
96
The term sister chromatid means:
similar chromosomes shared between brothers (or sisters)
a pair of homologous chromosomes
a pair of chromosomes that are not the sex chromosomes
duplicated identical strands of DNA that make up a chromosome
duplicated identical strands of DNA that make up a chromosome
Besides growth, what is the other normal function of mitosis?
cancer
repair and regenerate body parts
sexual reproduction
repair and regenerate body parts
Which of the following is NOT a correct statement about homologous chromosomes?
they have the same size
they have the same centromere location
they can have different genes in different locations
they can have different versions of genes (alleles)
they can have different genes in different locations
Taxol is a drug that stabilizes spindle fibers and prevents them from shortening so that treated cells fail to complete mitosis. At which phase are cells treated with taxol likely to stop?
interphase
S phase
metaphase
anaphase
telophase
metaphase
What is crossing over and when does it occur?
Chromosomes move to opposite sides of a cell during telophase of mitosis
non-sister chromatids exchange segments of DNA during stage I (meiosis I) of meiosis
chromatids are pulled apart and move to opposite sides of a cell during stage II (meiosis II) of meiosis
non-sister chromatids exchange segments of DNA during stage I (meiosis I) of meiosis
In a somatic cell after the S phase of interphase, how many alleles for each gene are present?
1
2
4
8
4
Which gender determines the sex of the children in humans?
men
women
men
