Lc. 11 (cell reproduction) Flashcards
Quizzes & Openstax
A diploid cell has_______ the number of chromosomes as a haploid cell.
a) one-fourth
b) half
c) twice
d) four times
c) twice
An organism’s traits are determined by the specific combination of inherited _____.
a) cells.
b) genes.
c) proteins.
d) chromatids.
b) genes.
The first level of DNA organization in a eukaryotic cell is maintained by which molecule?
a) cohesin
b) condensin
c) chromatin
d) histone
d) histone
Identical copies of chromatin held together by cohesin at the centromere are called _____.
a) histones.
b) nucleosomes.
c) chromatin.
d) sister chromatids.
d) sister chromatids.
Chromosomes are duplicated during what stage of the cell cycle?
a) G1 phase
b) S phase
c) prophase
d) prometaphase
b) S phase
Which of the following events does not occur during some stages of interphase?
a) DNA duplication
b) organelle duplication
c) increase in cell size
d) separation of sister chromatids
d) separation of sister chromatids
The mitotic spindles arise from which cell structure?
a) centromere
b) centrosome
c) kinetochore
d) cleavage furrow
b) centrosome
Attachment of the mitotic spindle fibers to the kinetochores is a characteristic of which stage of mitosis?
a) prophase
b) prometaphase
c) metaphase
d) anaphase
b) prometaphase
Unpacking of chromosomes and the formation of a new nuclear envelope is a characteristic of which stage of mitosis?
a) prometaphase
b) metaphase
c) anaphase
d) telophase
d) telophase
Separation of the sister chromatids is a characteristic of which stage of mitosis?
a) prometaphase
b) metaphase
c) anaphase
d) telophase
c) anaphase
The chromosomes become visible under a light microscope during which stage of mitosis?
a) prophase
b) prometaphase
c) metaphase
d) anaphase
a) prophase
The fusing of Golgi vesicles at the metaphase plate of dividing plant cells forms what structure?
a) cell plate
b) actin ring
c) cleavage furrow
d) mitotic spindle
a) cell plate
Which of the following is the correct order of events in mitosis?
a) Sister chromatids line up at the metaphase plate. The kinetochore becomes attached to the mitotic spindle. The nucleus reforms and the cell divides. Cohesin proteins break down and the sister chromatids separate.
b) The kinetochore becomes attached to the mitotic spindle. Cohesin proteins break down and the sister chromatids separate. Sister chromatids line up at the metaphase plate. The nucleus reforms and the cell divides.
c) The kinetochore becomes attached to the cohesin proteins. Sister chromatids line up at the metaphase plate. The kinetochore breaks down and the sister chromatids separate. The nucleus reforms and the cell divides.
d) The kinetochore becomes attached to the mitotic spindle. Sister chromatids line up at the metaphase plate. Cohesin proteins break down and the sister chromatids separate. The nucleus reforms and the cell divides.
d) The kinetochore becomes attached to the mitotic spindle. Sister chromatids line up at the metaphase plate. Cohesin proteins break down and the sister chromatids separate. The nucleus reforms and the cell divides.
At which of the cell-cycle checkpoints do external forces have the greatest influence?
a) G1 checkpoint
b) G2 checkpoint
c) M checkpoint
d) G0 checkpoint
a) G1 checkpoint
What is the main prerequisite for clearance at the G2 checkpoint?
a) cell has reached a sufficient size
b) an adequate stockpile of nucleotides
c) accurate and complete DNA replication
d) proper attachment of mitotic spindle fibers to kinetochores
c) accurate and complete DNA replication
If the M checkpoint is not cleared, what stage of mitosis will be blocked?
a) prophase
b) prometaphase
c) metaphase
d) anaphase
d) anaphase
Many of the negative regulator proteins of the cell cycle were discovered in what type of cells?
a) gametes
b) cells in G0
c) cancer cells
d) stem cells
c) cancer cells
___________ are changes to the order of nucleotides in a segment of DNA that codes for a protein.
a) Proto-oncogenes
b) Tumor suppressor genes
c) Gene mutations
d) Negative regulators
c) Gene mutations
A gene that codes for a positive cell-cycle regulator is called a(n) _____.
a) kinase inhibitor.
b) tumor suppressor gene.
c) proto-oncogene.
d) oncogene.
c) proto-oncogene.
Which eukaryotic cell-cycle event is missing in binary fission?
a) cell growth
b) DNA duplication
c) karyokinesis
d) cytokinesis
c) karyokinesis
FtsZ proteins direct the formation of a _______ that will eventually form the new cell walls of the daughter cells.
a) contractile ring
b) cell plate
c) cytoskeleton
d) septum
d) septum
Nucleoli are present during
interpahse
cytokinesis often, but not always, accompanies
telophase
chromosomes become visible during
prophase
centromeres divide and sister chromatids become full-fledged chromosomes during
anaphase
spindle fibers attach to kinetochores during
prometaphase
During interphase, the cell’s DNA replicates, producing an identical copy of each DNA molecule. By the end of mitosis, one copy of each DNA molecule has been moved to each daughter cell.
unreplicated chromosome
-> (DNA replication) replicated chromosomes
-> sister chromatid
-> (mitosis) unreplicated chromosomes
Which of the following statements does not correctly describe the role of a cellular structure in mitosis?
a) The centrosomes are the organizing centers for the formation of the mitotic spindle in animal cells.
b) The kinetochore is the structure that holds the sister chromatids together.
c) During mitosis, the attachment of the sister chromatids to each other at the centromere is broken, permitting the chromatids to separate.
d) Every chromosome is attached to the mitotic spindle by two sets of microtubules, one extending from each pole of the cell.
b) The kinetochore is the structure that holds the sister chromatids together.
Which of the following correctly matches a phase of the cell cycle with its description?
a) M: duplication of DNA
b) G1: follows cell division
c) S: immediately precedes cell division
d) none of these are correctly matched
e) G2: cell division
b) G1: follows cell division
A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in
a) G2
b) prophase
c) S
d) G1
d) G1
During mitosis, microtubules attach to the chromosomes at the
kinetochores
in dividing cells, most of the cells growth during
interphase
the ________ are the organizing centers for microtubules involved in separating chromosomes during mitosis
centrosomes
after chromosomes condense, the _______ is the region where the identical DNA molecules are most tightly attached to each other
centromere
DNA replication produces two identtical DNA molecules, called_______, which seperate during mitosis
sister chromatids
the _______ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division
mitotic spindles
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain?
92
No answer text provided.
23
46
92
Which is an enzyme?
a) cyclin-dependent kinase
b) cyclin
a) cyclin-dependent kinase
The cyclin dependent kinase is active when bound to the cyclin. (T/F)
false
