Mitotic Spindle Structure and Function

What is the primary function of the mitotic spindle during mitosis?

To control chromosome movement (correct)
To replicate DNA
To synthesize proteins
To degrade unnecessary organelles

Where does the assembly of spindle microtubules begin in animal cells?

In the nucleus
In the centrosome (correct)
In the mitochondria
In the cytoplasm

What is the function of kinetochores during mitosis?

To attach to spindle microtubules (correct)
To degrade proteins
To replicate chromosomes
To separate sister chromatids

What is the term for a radial array of short microtubules that extends from each centrosome?

Aster (B) Signup and view all the answers

What is the term for the plane midway between the spindle's two poles where chromosomes line up during metaphase?

Metaphase plate (D) Signup and view all the answers

What is the term for the microtubules that attach to kinetochores and move chromosomes during prometaphase?

Kinetochore microtubules (C) Signup and view all the answers

What is the process by which prokaryotes, such as bacteria and archaea, reproduce?

Binary fission (B) Signup and view all the answers

What is the starting point of DNA replication in a bacterial chromosome?

Origin of replication (A) Signup and view all the answers

What happens to the replicated chromosomes during binary fission?

They actively move apart (C) Signup and view all the answers

What is the result of the plasma membrane pinching inward during binary fission?

Cell division (B) Signup and view all the answers

What is the outcome of replication in binary fission?

Two identical chromosomes (B) Signup and view all the answers

What is the stage of cell division where the chromosomes line up at the center of the cell?

Metaphase (B) Signup and view all the answers

What is the role of the enzyme separase in anaphase?

To cleave the cohesins (B) Signup and view all the answers

What happens to the sister chromatids during anaphase?

They move along the kinetochore microtubules toward opposite ends of the cell (B) Signup and view all the answers

What is the mechanism by which motor proteins move chromosomes along microtubules during anaphase?

The 'Pac-man' mechanism (A) Signup and view all the answers

What is the fate of the microtubules at the kinetochore ends during anaphase?

They depolymerize to form shorter microtubules (D) Signup and view all the answers

What is the role of the motor proteins on kinetochores during anaphase?

To move the chromosomes along the microtubules (A) Signup and view all the answers

What is the result of the experiment that suggests the 'Pac-man' mechanism of chromosome movement?

Chromosomes move poleward along stationary microtubules (B) Signup and view all the answers

What is the result of replication finishing in a bacterial cell?

Two daughter cells result (B) Signup and view all the answers

What is the likely origin of mitosis?

From binary fission in prokaryotes (A) Signup and view all the answers

What is the main difference between the cell division in bacteria and eukaryotes?

The presence or absence of a nuclear envelope (D) Signup and view all the answers

What is the term for the process by which a bacterial cell divides into two daughter cells?

Binary fission (D) Signup and view all the answers

What is the characteristic of cancer cells in terms of cell division?

They are able to escape the usual controls on the cell cycle (B) Signup and view all the answers

What is the reason for the differences in the frequency of cell division in different types of cells?

Differences in the regulation at the molecular level (D) Signup and view all the answers

What is the most important checkpoint for many cells?

G1 checkpoint (C) Signup and view all the answers

What happens if a cell receives a go-ahead signal at the G1 checkpoint?

It will continue with the S, G2, and M phases and divide (D) Signup and view all the answers

What is the purpose of the mechanism that ensures daughter cells have the correct number of chromosomes?

To ensure proper spindle attachment (D) Signup and view all the answers

What happens if a cell does not receive the go-ahead signal at the G1 checkpoint?

It will exit the cell cycle and enter the G0 phase (B) Signup and view all the answers

What is the name of the non-dividing state that cells can enter if they do not receive the go-ahead signal at the G1 checkpoint?

G0 phase (A) Signup and view all the answers

What is the significance of full chromosome attachment at the metaphase plate?

It allows the cell to proceed with anaphase (A) Signup and view all the answers