Chromosome Behaviour in Mitosis (CIE AS Biology)

The photomicrograph shows cells in different stages of mitosis.

In which order do these stages occur?

Each of the following events takes place during mitosis.

In which order do the events take place?

The mitotic spindle has a key role in mitosis.

What macromolecule is the spindle made from?

The diagram shows the chromosomes of a squashed cell during mitosis.

Which stage of mitosis is the cell in and what is the haploid chromosome number in this species?

The diagram shows a plant cell’s chromosomes during metaphase.

Which row correctly describes this plant cell during metaphase?

What row correctly describes an animal cell’s nuclear envelope, centrioles and spindle during mitosis?

Colchicine is a drug that is used to treat imflammaton and pain. Its action within cells is to stop chromatids from separating during mitosis.

Which phase will the cell reach and then stop dividing?

Which is the correct statement concerning cell and nuclear division?

Which statement about stages in mitosis is correct? 

What of the following does not happen in an animal cell cycle? 

The graphs show measurements taken from metaphase of mitosis onwards. 

The graphs are to scale when compared to one another.

Which row correctly identifies each graph?

What features would be observed in a human cell immediately before the onset of mitosis?

The graph shows the changes in the quantity of DNA present in the nucleus of one cell at different stages of a mammal’s life cycle.

Which stage takes place at X?

The protein called mitosis-promoting factor (MPF) has been discovered in cells and is known to cause prophase to start. Usually MPF breaks down and stops functioning during anaphase.

What is a possible consequence of MPF not breaking down?

Some chemotherapy treatments used to stop tumour growth work by preventing the DNA double helix from uncoiling and separating.

During which stage of the cell cycle would they act?

Nocodazole is a chemical used in the study of mitosis. It causes all mitotic cells to stop dividing at metaphase.

Which statements correctly identify how this chemical might work?

Cancer cells have distinctive differences from normal cell, for example they are sometimes much bigger and sometime smaller and they don’t produce proteins required on the cell surface for cell adhesion and signalling.

Which stage of the cell cycle is most affected in cancer cells?

A student studied a garlic root tip under a microscope and records the following data.

What percentage of studied cells have chromosomes visible and have pairs of chromatids joined together?

The graph shows three measurements obtained following metaphase of mitosis.

What measurements do the curves represent?

Cells of a root tip meristem were studied and the number of cells in each phase of the cell cycle are noted in the table below.

A complete cell cycle of a root tip meristem cell is 24 hours. 

How long do these cells take to line chromosomes up on the cell equator?