mitosis experiment
Practical 1: Observation of mitosis in garlic root tips
Introduction
The practical will involve the preparation, observation, and classification, of the various stages of mitosis by observing garlic root tips using a microscope. The study comes under the heading of cytogenetics which is the visual characterisation of genetic material and the study of how that material reacts during the life of the cell.
Strictly speaking, mitosis is the division of the nucleus into two daughter nuclei that are identical to one another and to the parent nucleus. Mitosis is part of the cell cycle which also includes chromosome replication and division of the cytoplasm i.e. cytokinesis. The chromosomes are always present in the nucleus but they are most easily seen when the nucleus divides. During this division process chromosomes contract significantly after which they can be seen under the light microscope as distinct thread-like structures. Chromosomes are usually studied by obtaining actively dividing tissue, fixing the material to kill the cells, and to preserve their structure, staining the chromosomes with a dye, and then observing them with a microscope.
By studying mitosis in this way, changes that occur in the chromosomes can be observed and the visible events that bring about the process of heredity in somatic (body) cells can be seen. Furthermore, using certain chemicals it is possible to arrest the division process at the end of prophase and 'catch' the chromosomes in their most condensed form (see karyotyping). This technique permits the study of number, size, and form, of the chromosomes, and enables us to see how these aspects of chromosome organisation vary from one species to another.
General Procedures for making Slides to study Mitosis
Cells, dividing by mitosis, can be found in the actively growing (meristems) part of an organism and in tissues where the cells require continual replacement. It is usual to work with meristematic regions of the roots although
Introduction
The practical will involve the preparation, observation, and classification, of the various stages of mitosis by observing garlic root tips using a microscope. The study comes under the heading of cytogenetics which is the visual characterisation of genetic material and the study of how that material reacts during the life of the cell.
Strictly speaking, mitosis is the division of the nucleus into two daughter nuclei that are identical to one another and to the parent nucleus. Mitosis is part of the cell cycle which also includes chromosome replication and division of the cytoplasm i.e. cytokinesis. The chromosomes are always present in the nucleus but they are most easily seen when the nucleus divides. During this division process chromosomes contract significantly after which they can be seen under the light microscope as distinct thread-like structures. Chromosomes are usually studied by obtaining actively dividing tissue, fixing the material to kill the cells, and to preserve their structure, staining the chromosomes with a dye, and then observing them with a microscope.
By studying mitosis in this way, changes that occur in the chromosomes can be observed and the visible events that bring about the process of heredity in somatic (body) cells can be seen. Furthermore, using certain chemicals it is possible to arrest the division process at the end of prophase and 'catch' the chromosomes in their most condensed form (see karyotyping). This technique permits the study of number, size, and form, of the chromosomes, and enables us to see how these aspects of chromosome organisation vary from one species to another.
General Procedures for making Slides to study Mitosis
Cells, dividing by mitosis, can be found in the actively growing (meristems) part of an organism and in tissues where the cells require continual replacement. It is usual to work with meristematic regions of the roots although