80 Questions
What is a chromosome in eukaryotic cells?
A double helix of DNA wrapped around histones
How many chromosomes do humans typically have?
46
What is the role of cohesins in mitosis?
Form rings that hold sister chromatids together
What are condensins responsible for in mitosis?
Condensing the DNA
What do kinetochore proteins do in relation to chromosomes?
Connect microtubules to chromosomes
What is the function of the spindle apparatus in mitosis?
Move replicated chromosomes during early mitosis
Which structure serves as the MTOC in animal cells?
Centrioles
What is the function of kinetochore microtubules?
Attaching to chromosomes
Which phase of the cell cycle involves cell growth and protein content increase?
G1 phase
What defines the two poles of the spindle apparatus?
Centrioles
Where do polar microtubules extend from?
Spindle poles
Which structure anchors the spindle poles in place?
Spindle poles
What is the main difference between prokaryotic and eukaryotic cell division?
Prokaryotes divide by binary fission, while eukaryotes divide by mitosis and cytokinesis.
What must happen for a cell to divide successfully?
Copying the DNA, separating the copies, and dividing the cytoplasm.
How does a prokaryote differ from a eukaryote in terms of genetic material?
Prokaryotes have a single circular DNA strand, while eukaryotes have linear chromosomes.
What are the three essential events that need to happen for a cell to divide?
Copying the DNA, separating the copies, and dividing the cytoplasm.
How does a prokaryote cell ensure that each daughter cell gets a copy of replicated DNA?
Each daughter cell receives one copy of replicated parental DNA.
What is the difference between prokaryotic and eukaryotic chromosome structures?
Prokaryotes have a single circular DNA strand forming a chromosome, while eukaryotes have linear chromosomes.
What is the name of the arrested state in which nondividing cells get permanently stuck in G1 phase?
G0 state
Which phase of the cell cycle is essentially eliminated in rapidly dividing cells?
G1 phase
What are the two types of defects found in cancerous cells according to the text?
Defects that activate the proteins required for cell growth when they should be active, and defects that prevent tumour suppressor genes from shutting down the cell cycle.
What might happen when cells bypass the cell-cycle checkpoints according to the text?
Cells might form malignant tumours
How do benign tumours differ from malignant tumours as described in the text?
Benign tumours are noncancerous and noninvasive; malignant tumours are cancerous and invasive.
What happens to cells during metastasis according to the text?
Cells invade surrounding tissues.
During which phase of the cell cycle does DNA replication occur?
S phase
What is the main event in mitosis?
Division of the replicated chromosomes
How is cytokinesis different in plant cells compared to animal cells?
Animal cells form a cell plate during cytokinesis.
What is the role of the contractile ring in animal cell cytokinesis?
Pinching the cytoplasm to form a cleavage furrow
Which phase of the cell cycle involves the preparation for mitosis and cytokinesis?
G2 phase
'M Phase' in the cell cycle consists of which two distinct events?
Mitosis and cytokinesis
During binary fission, a prokaryote cell replicates its ______
DNA
To divide successfully, a cell must satisfy the requirement of each daughter cell receiving the full complement of ______ material
genetic
Eukaryotic cells divide by ______ and cytokinesis
mitosis
Binary fission in prokaryotes is the process by which a single cell becomes two ______ cells
daughter
Prokaryotic cells have a single circular strand of DNA, while eukaryotic cells have ______ chromosomes
linear
The process of cell division must ensure that the parent cell contributes sufficient ______ components to each daughter cell
cytoplasmic
In eukaryotic cells, a chromosome is a long double helix of DNA wrapped around proteins called __________
histones
Every species has a characteristic number of __________
chromosomes
Before mitosis, each chromosome is __________
replicated
Chromatids attached together are called sister __________
chromatids
The spindle apparatus produces mechanical forces that move replicated chromosomes during early mitosis and pull chromatids apart in late __________
mitosis
The spindle apparatus is made of __________, formed from microtubule-organizing centres (MTOCs)
microtubules
During mitosis, the division of the replicated chromosomes occurs in the ______ phase
M
In animal cells, MTOCs are centrosomes, each containing a pair of ______.
centrioles
In plant cells, MTOCs are NEDD1 ______.
complexes
Cytokinesis in animal cells is initiated by the formation of a ring of actin filaments called the ______ ring
contractile
Astral microtubules anchor spindle poles in ______.
place
In plant cells, the division of the cell is achieved by constructing a new ______
cell wall
Microtubules that attach to chromosomes are called kinetochore ______.
microtubules
The fusion of the cell plate with the original cell wall completes cytokinesis in ______ cells
plant
The cell cycle consists of two distinct stages: 1) M phase: the time during which the parent cell divides into two daughter ______.
cells
During cytokinesis, the cytoplasm of the cell is pinched to form a cleavage furrow in ______ cells
animal
The ______ phase of the cell cycle consists of interphase, mitosis, and cytokinesis
cell cycle
Cells are growing and preparing for division or are fulfilling their specialized ______.
functions
Cell-cycle length can vary greatly among cell types, mostly due to variation in the length of ______ phase.
G1
Nondividing cells get permanently stuck in ______ phase. This arrested state is called the G0 state.
G1
Cancerous cells have two types of defects: Defects that activate the proteins required for cell growth when they should not be active. Defects that prevent tumour suppressor genes from shutting down the cell cycle. Two types of tumours: Benign tumours are noncancerous and noninvasive. Malignant tumours are cancerous and ______.
invasive
Cells that divide without control may form a ______.
tumour
Cell-Cycle Checkpoints: There are four cell-cycle checkpoints: G1 checkpoint, G2 checkpoint, ______ checkpoints.
M-Phase
Benign tumours are ______ and noninvasive. Malignant tumours are cancerous and invasive.
noncancerous
In animal cells, NEDD1 complexes serve as MTOCs.
False
The spindle apparatus defines a single pole instead of two poles.
False
Polar microtubules extend inward towards each spindle pole.
False
Astral microtubules play a role in moving replicated chromosomes during mitosis.
False
Kinetochore microtubules attach to chromosomes in animal cells but not in plant cells.
False
Centrosomes are the same as MTOCs in animal cells.
False
NEDD1 complexes are primarily found in plant cells during cell division.
False
Spindle apparatus is responsible for moving replicated chromosomes during late mitosis.
False
Kinetochore microtubules attach to the centromere region of replicated chromosomes.
True
MTOCs are essential for anchoring spindle poles in place during cell division.
True
NEDD1 complexes are responsible for anchoring the spindle poles in place during mitosis
False
Centrosomes in animal cells do not contain any microtubules
True
The spindle apparatus is directly involved in the division of the cytoplasm during cytokinesis
False
Kinetochore microtubules are responsible for anchoring the centrosomes in place during cell division
False
Animal cells utilize NEDD1 complexes as their MTOCs during mitosis
False
Centrosomes are found in prokaryotic cells.
False
The NEDD1 complex is involved in forming the spindle apparatus during mitosis.
True
Kinetochore microtubules attach to the centrosomes during cell division.
False
MTOCs are only present in animal cells and not in plant cells.
False
The spindle apparatus is primarily composed of DNA in eukaryotic cells.
False
Learn about the role of Microtubule Organizing Centers (MTOCs) in both animal and plant cells, and understand the functions of different types of microtubules like kinetochore microtubules. Explore how MTOCs define spindle poles and how microtubules contribute to cell division.
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