2.1 what is genetics

• chromosome: a strand of DNA that contains the instructions for making proteins. Chromosomes become x-shaped before cells divide
• gene: a segment of DNA that carries instructions that result in the production of proteins
• deoxyribonucleic acid (DNA): the twisted ladder-shaped molecule that contains the genetic information of cells
• genetics: the science of gene function and inheritance
• karyotype: the image that organizes the chromosomes of a cell in relation to the number, shape and size
• centromere: the region of a replicated chromosome that attaches the two identical copies during cell division
• enzyme: speed up chemical reactions where molecules are broken apart or put together
• structural: structural support and frameworks are created to attach other proteins
• transport: materials are moved within the cell or body
• hormone: act as signals to co-ordinate and regulate activities in the body
• contractile: change shape and can create larger movements when they work together
• defensive: protect the body against disease
• energy: serves as a source of chemical potential energy that can be released by its decomposition
• amniocentesis: a prenatal test done to look at the karyotype of an unborn child
• autosomal cells: a cell of the body not involved in sexual reproduction
• homologous chromosomes: a pair of chromosomes that would be matched during karyotyping because they have the same length, centromere position, and staining pattern
• replicate: to produce an exact copy of a DNA strand
• daughter cells: the two identical cells produced during mitosis
• mitosis: the division of an autosomal cell into two identical daughter cells
• diploid cells: cells with pairs of homologous chromosomes
• asexual reproduction: the production of genetically identical offspring from one individual
• gamete: a sex cell, such as a sperm and an egg, produced during meiosis with only one copy of each chromosome type
• meiosis: a two-stage form of cell division that produces gametes with only half of the number of chromosomes as the origonal cell
• crossing over: the exchange of corresponding segments of DNA between maternal and paternal chromosomes during meiosis
• haploid cell: a cell that has only one member from each pair of homologous chromosomes
• cross-pollinate: transferring pollen between genetically different plants
• self-pollenate: transferring pollen from one plant to the female part of the same plant or to another plant with the same genetic makeup