CHAPTER 16 - Chromosomes, genes, and proteins

• Chromosomes are a length of DNA, found in the nucleus of a cell which contains genetic information in the form of many different genes
• DNA is a molecule that contains genetic information
• Gene is a length of DNA that codes for one protein
• Alleles are alternative forms of a gene
• Haploid cells are one set of chromosomes
• Diploid cells are two sets of chromosomes
• Mitosis is cell division where cells are genetically identified
• Meiosis is cell variation where the cells are genetically different
• Homozygous alleles are two identical alleles e.g. BB or bb
• Heterozygous alleles are two different alleles e.g. Bb
• Phenotype is an organism's observable characteristics
• Genotype is the genetic makeup of an organism in terms of the alleles present e.g. BB, bb
• Dominant alleles are expressed if it is present; big letter e.g. B
• Recessive alleles are only expressed when there is no dominant allele present; small letter e.g. b
• Inheritance is the passing of genetic information from one generation to the next.
• Punnett squares are diagrams that show the possible combinations of alleles that can be produced in a cross
• Test crosses are used to determine whether a particular gene is dominant or recessive
• A sex chromosome is a chromosome that determines the sex of an organism
• X chromosomes are a woman's sex chromosome
• Y chromosomes are a man's sex chromosome
• Sex linkage refers to the inheritance pattern of traits linked to specific sex chromosomes