Flashcards
1 of 30
Cell Division | Definitions
Deck complete
You’ve reviewed 30 terms. Keep up the good work!
tap to flip
Print
Cell Division | Definitions
Cell Continuity
All cells develop from pre-existing cells. Existing cells divide and become new cells.
Cell Division
The process of a living cell splitting to form two separate living cells.
Chromosomes
Tightly-coiled threads of DNA and protein which become visible in the nucleus of a cell at cell division. They are a very efficient way of carrying genetic information.
Chromatin
When a cell is not dividing, the chromosomes are in long thin threads called chromatin.
Genes
A gene is a section of a chromosome that codes for the production of a particular protein. Genes are units of inheritance in living organisms, controlling the characteristic features of that organism.
Haploid Cell
Haploid cells are the product of meiosis and they have one set of chromosomes. For example, in humans, they contain 23 chromosomes (n=23). The reproductive cells, the sperm and the egg are examples of haploid cells.
Diploid Cell
Diploid cells are the result of the fusion of two haploid cells. They can undergo mitosis and they have two sets of chromosomes. For example, in humans, they contain 46 chromosomes (2n=46). All cells in the body, except the reproductive cells, are diploid cells.
Karyotype
A karyotype is a picture of a complete set of a person's chromosomes.
Homologous Chromosomes
Homologous chromosomes are matching pairs of chromosomes.
The Cell Cycle
The cell cycle is the collective term for when the cell is in a non-dividing state called interphase and when the nucleus divides during either mitosis or meiosis.
Interphase
Interphase is the time when the cell is not dividing and makes up 90% of the cell cycle. During Interphase, the cell is preparing for nuclear division and the chromosomes can be found in the nucleus as long thin strands called chromatin.
DNA Replication
This is where chromosomes produce identical copies of themselves. DNA replication occurs during interphase.
Mitosis
Mitosis is the division of the nucleus to produce two identical daughter nuclei, each containing the same number and type of chromosomes with identical genes.
Prophase
At the end of interphase, the chromatin shorten to become chromosomes. The chromosomes are seen as double-stranded structures attached at centromeres. Spindle fibres form at the pole of each cell in centrioles. The nuclear membrane starts to break down which allows the chromosomes to move around the cytoplasm. The nucleolus breaks down and disappears.
Metaphase
By metaphase, the nuclear membrane is completely broken down. The chromosomes line themselves up at the middle of the cell. Spindle fibres attach to the chromosomes at the centromere from the poles.
Anaphase
The spindle fibres shorten and the centromere breaks. The double-stranded chromosomes are pulled apart and a chromosome from each pair is pulled towards opposite poles.
Telophase
The spindle fibres break down and disappear. A new nuclear membrane forms around the two sets of chromosomes. Nucleoli start to reform. The chromosomes elongate into chromatin. At the end of telophase, mitosis is complete as the original nucleus has divided into two identical nuclei.
Unicellular Organisms
Also known as single-celled organisms, these are organisms of one cell only. All prokaryotes are unicellular. Examples of single-celled organisms include all bacteria, amoeba from the Kingdom Protista and yeast from the Kingdom Fungi.
Multicellular Organisms
Organisms composed of more than one cell. Examples of multicellular organisms include humans and animals.
Cleavage Furrow
A cleavage furrow is an indentation of the cytoplasm that occurs along the equator of the cell. It begins on the outside of the cell an deepens until it divides the cytoplasm in two which then splits the animal cell into two identical cells.
Cell Plate
In plant cells, the cell wall prevents a cleavage furrow from forming. Instead, a cell plate forms. Small, membrane-enclosed sacs called vesicles, which contain cellulose, line up along the centre of the cell. These vesicles fuse to form a cell plate.
Cancer
Cancer is a group of disorders in which cells lose control over both the rate of mitosis and the number of times mitosis takes place.
Carcinogens
Cancer-causing agents are known as carcinogens. These carcinogens cause cancer by causing genetic mutations or changes to the DNA found in cells.
Tumour
Tumours are the mass or growth of cells that form as a result of the carcinogens. There are two types of tumour: benign and malignant.
Benign Tumour
Benign tumours are not life-threatening. They stop dividing after some time. Fibroids in the uterus are an example of a benign tumour.
Malignant Tumour
Malignant tumours can be life-threatening. They have the ability to invade other cells and continue dividing indefinitely. Carcinomas are an example of a malignant tumour.
Metastasis
Metastasis is the movement of malignant cells.
Meiosis
A type of nuclear division where four daughter nuclei are produced, each containing half the number of chromosomes as the parent nucleus. Meiosis can only occur in diploid cells. The four daughter nuclei that are produced are haploid cells.
Somatic Cells
All normal body cells that are not gametes.
Diversity
The large variety of organisms on earth.
Cut dotted horizontal lines. Fold vertical line.
Cell Continuity
All cells develop from pre-existing cells. Existing cells divide and become new cells.
Cell Division
The process of a living cell splitting to form two separate living cells.
Chromosomes
Tightly-coiled threads of DNA and protein which become visible in the nucleus of a cell at cell division. They are a very efficient way of carrying genetic information.
Chromatin
When a cell is not dividing, the chromosomes are in long thin threads called chromatin.
Genes
A gene is a section of a chromosome that codes for the production of a particular protein. Genes are units of inheritance in living organisms, controlling the characteristic features of that organism.
Haploid Cell
Haploid cells are the product of meiosis and they have one set of chromosomes. For example, in humans, they contain 23 chromosomes (n=23). The reproductive cells, the sperm and the egg are examples of haploid cells.
Diploid Cell
Diploid cells are the result of the fusion of two haploid cells. They can undergo mitosis and they have two sets of chromosomes. For example, in humans, they contain 46 chromosomes (2n=46). All cells in the body, except the reproductive cells, are diploid cells.
Karyotype
A karyotype is a picture of a complete set of a person's chromosomes.
Homologous Chromosomes
Homologous chromosomes are matching pairs of chromosomes.
The Cell Cycle
The cell cycle is the collective term for when the cell is in a non-dividing state called interphase and when the nucleus divides during either mitosis or meiosis.
Interphase
Interphase is the time when the cell is not dividing and makes up 90% of the cell cycle. During Interphase, the cell is preparing for nuclear division and the chromosomes can be found in the nucleus as long thin strands called chromatin.
DNA Replication
This is where chromosomes produce identical copies of themselves. DNA replication occurs during interphase.
Mitosis
Mitosis is the division of the nucleus to produce two identical daughter nuclei, each containing the same number and type of chromosomes with identical genes.
Prophase
At the end of interphase, the chromatin shorten to become chromosomes. The chromosomes are seen as double-stranded structures attached at centromeres. Spindle fibres form at the pole of each cell in centrioles. The nuclear membrane starts to break down which allows the chromosomes to move around the cytoplasm. The nucleolus breaks down and disappears.
Metaphase
By metaphase, the nuclear membrane is completely broken down. The chromosomes line themselves up at the middle of the cell. Spindle fibres attach to the chromosomes at the centromere from the poles.
Anaphase
The spindle fibres shorten and the centromere breaks. The double-stranded chromosomes are pulled apart and a chromosome from each pair is pulled towards opposite poles.
Telophase
The spindle fibres break down and disappear. A new nuclear membrane forms around the two sets of chromosomes. Nucleoli start to reform. The chromosomes elongate into chromatin. At the end of telophase, mitosis is complete as the original nucleus has divided into two identical nuclei.
Unicellular Organisms
Also known as single-celled organisms, these are organisms of one cell only. All prokaryotes are unicellular. Examples of single-celled organisms include all bacteria, amoeba from the Kingdom Protista and yeast from the Kingdom Fungi.
Multicellular Organisms
Organisms composed of more than one cell. Examples of multicellular organisms include humans and animals.
Cleavage Furrow
A cleavage furrow is an indentation of the cytoplasm that occurs along the equator of the cell. It begins on the outside of the cell an deepens until it divides the cytoplasm in two which then splits the animal cell into two identical cells.
Cell Plate
In plant cells, the cell wall prevents a cleavage furrow from forming. Instead, a cell plate forms. Small, membrane-enclosed sacs called vesicles, which contain cellulose, line up along the centre of the cell. These vesicles fuse to form a cell plate.
Cancer
Cancer is a group of disorders in which cells lose control over both the rate of mitosis and the number of times mitosis takes place.
Carcinogens
Cancer-causing agents are known as carcinogens. These carcinogens cause cancer by causing genetic mutations or changes to the DNA found in cells.
Tumour
Tumours are the mass or growth of cells that form as a result of the carcinogens. There are two types of tumour: benign and malignant.
Benign Tumour
Benign tumours are not life-threatening. They stop dividing after some time. Fibroids in the uterus are an example of a benign tumour.
Malignant Tumour
Malignant tumours can be life-threatening. They have the ability to invade other cells and continue dividing indefinitely. Carcinomas are an example of a malignant tumour.
Metastasis
Metastasis is the movement of malignant cells.
Meiosis
A type of nuclear division where four daughter nuclei are produced, each containing half the number of chromosomes as the parent nucleus. Meiosis can only occur in diploid cells. The four daughter nuclei that are produced are haploid cells.
Somatic Cells
All normal body cells that are not gametes.
Diversity
The large variety of organisms on earth.