It’s Just a Phase
What stage of the cell cycle takes up most of a cell’s life?
Interphase
What process produces new cells from existing cells?
Cell division
During which stage do chromosomes line up across the middle of the cell?
Metaphase
During which stage of mitosis are chromosomes pulled toward opposite ends of the cell?
Anaphase
What happens during cytokinesis?
The cytoplasm divides.
A cell is growing, carrying out normal functions, and getting ready to divide. Which stage is it most likely in?
Interphase
You scrape your knee, and several days later new skin covers the damaged area. Which function of cell division is responsible?
Repairing damaged tissue
A microscope image shows chromosomes becoming visible and the nucleus beginning to break down. Which stage is occurring?
Prophase
Why must chromosomes be copied before mitosis begins?
So each daughter cell can receive a complete copy of the genetic information.
A cell has completed mitosis but has not completed cytokinesis. How many nuclei would you expect it to contain, and how many separate cells would there be?
Two nuclei, but still one cell.
Put these events in the correct order: cytokinesis, interphase, mitosis.
Interphase → mitosis → cytokinesis
A child grows several inches taller over a few years. Why does cell division help make this possible?
Cell division increases the number of cells in the body.
Saghatel says, “Anaphase happens before metaphase because the chromosomes need to separate before they can line up.” What is wrong with this explanation?
Chromosomes line up during metaphase first, then separate during anaphase.
What would most likely happen if a cell entered mitosis without copying its DNA first?
The daughter cells would not receive complete sets of genetic information.
Why can’t a plant cell simply pinch inward during cytokinesis the same way an animal cell does?
The rigid cell wall prevents the cell from pinching inward.
A scientist observes a cell with two complete nuclei, but the cytoplasm has not yet fully separated. Which major stage has just finished, and what stage must happen next?
Mitosis has finished; cytokinesis happens next.
Two organisms both use cell division, but one uses it to heal a cut while the other uses it to create a completely new organism. Explain the difference in the function of cell division in each case.
The first uses cell division for repair; the second uses it for reproduction.
A cell’s chromosomes line up normally, but the structures that pull them apart fail to work. Which stage would the cell be unable to complete successfully, and why?
Anaphase, because the chromosomes cannot separate and move to opposite sides.
A cell reaches the end of mitosis, but one chromosome never moved to the opposite side. Predict how this could affect the two daughter cells.
They could receive unequal or incomplete sets of chromosomes.
An animal cell and a plant cell are both beginning cytokinesis. Describe how their methods of division differ.
Animal cells pinch inward; plant cells build a cell plate in the center.
A cell successfully copies its DNA but does not grow enough or produce the materials needed for division. Explain why simply copying the DNA is not enough for the cell to divide successfully.
The cell must also grow and prepare the structures/materials needed for division. DNA replication is only one part of interphase.
A multicellular organism suddenly loses the ability to perform cell division. Predict two different problems the organism would eventually face and explain why.
It could not grow or replace/repair damaged or worn-out cells. Accept reproduction if applicable.
A scientist observes one cell in prophase and another in telophase. Describe two major differences they should see between the cells.
In prophase, chromosomes condense and the nucleus breaks down; in telophase, chromosomes are at opposite ends and new nuclei form.
Why is it important for chromosomes to line up in the middle of the cell before they are pulled apart?
Proper alignment helps ensure the chromosome copies separate evenly so each daughter cell receives the correct genetic information.
A plant cell completes mitosis normally, but it cannot form a cell plate. Predict what would happen and explain why.
The cell would not separate properly into two daughter cells because the cell plate is needed to form the new boundary/cell wall between them.