Glossary

anaphase

Fourth phase of mitosis after metaphase. Sister chromatids are pulled apart and each chromatid is now a chromosome.

apoptosis

Also known as programmed cell death, is a normal and controlled cellular process where a cell is instructed to die because it is no longer needed or because it may pose a threat to the organism.

binary fission

Binary fission is a method of asexual reproduction used by many prokaryotic organisms, including bacteria and archaea.

cell cycle

Life cycle of a single cell, from its birth until its division into two new daughter cells.

chiasmata

Chiasmata (singular: chiasma) are the points at which paired chromosomes (homologous chromosomes) physically cross over each other during the process of meiosis.

chromosomes

Made of organised and packaged DNA in the form of genes and are found within the cell nucleus.

cyclin-dependent kinases

Positive cell cycle regulator when bound to cyclins to form a complex. These enzymes phosphorylate and activate cyclin proteins enabling the action of cyclins to advance cell replication to the next phase.

cyclins

Proteins associated with progression of cell cycle.

cytoplasmic

Gel-like substance composed of water and dissolved chemicals.

diploid

Following the fusion of two haploid cells, a diploid cell is formed and contains two sets of chromosomes.

diploid cell

Following the fusion of two haploid cells, a diploid cell is formed and contains two sets of chromosomes.

eukaryotic

Plants, animals, protozoans, algae and fungi.

gametes

Reproductive cells that combine during sexual reproduction to form a new organism.

genome

Full complement of DNA within a cell organised into smaller, discrete units called genes, arranged on chromosomes and plasmids.

genomic DNA

Full complement of DNA within a cell organised into smaller, discrete units called genes, arranged on chromosomes and plasmids.

haploid cells

Cells that contain a single copy of each homologous chromosome. Includes sex cells (sperm and egg cells) in humans.

human growth hormone

Growth promoting hormone secreted by the anterior lobe of the pituitary gland and essential from growth in all tissues of the body.

interphase

Entire life cycle of a cell, excluding mitosis.

meiosis

The process by which haploid cells are formed. Consists of one round of chromosome duplication and two rounds of nuclear division.

metaphase

Third phase of mitosis and meiosis, characterised by the linear alignment of sister chromatids in the centre of the cell.

metaphase plate

Also known as equatorial plane. Imaginary plate roughly midway between two poles of the cell that occurs during mitosis and meiosis where sister chromatids line up prior to separation.

mitotic

Part of the cell cycle which includes mitosis and cytokinesis. In this phase DNA replicated in the interphase phase is separated and the cell divides.

mitotic phase

Part of the cell cycle which includes mitosis and cytokinesis. In this phase DNA replicated in the interphase phase is separated and the cell divides.

nucleus

Membrane-bound organelle found in most eukaryotic cells, often considered the control centre of the cell because it houses the cell’s genetic material, DNA (deoxyribonucleic acid).

plasma membrane

Selectively permeable barrier that separates the interior of a cell from its external environment.

prokaryotic

Archaea and bacteria.

prometaphase

Second phase of mitosis and meiosis. Chromosomes continue to condense, kinetochores appear at centromere and kinetochore microtubules attach.

prophase

First stage in mitosis and meiosis. Nuclear envelope begins to break down, spindle fibres start to appear, and chromosome condense and are visible.

proteins

Biological macromolecule comprised of one or more amino acid chains.

telophase

Final stage of mitosis and meiosis, preceding cytokinesis, characterised by the formation of two new daughter nuclei.