Genetics keywords

• haploid - having one of each type of chromosomes / or one complete set. can also describe cells which have half the chromosomes e.g. 23 in humans.
• chromosome - thread-like structures found in the nucleus. the arms are made of very long coils of DNA (contains the genes)
• Genotype - genetic composition of an organism - description of the genes you have
• Alleles - genes occupying the same position on homologous chromosomes - when you have 2 different versions of them they're called alleles instead of genes
• diploid - having 2 types of chromosomes/two complete sets. its a description of cells which have all 46 chromosomes
• phenotype - physical characteristics of the organism
• gene - section of chromosomes concerned with a particular aspect of life - a section of a DNA molecule
• recessive - gene whose instructions are ignored in the presence of a dominant allele - the allele which doesn't usually affect how the organism turns out
• homologous - chromosome which look similar and are concerned with the same aspects of life
• genetics - the study of inheritance
• DNA - a molecule which contains genes - shaped like a double helix
• Dominant - refers to an allele or gene, the one which determines the characteristics that appear
• gamete - sex cell e.g. sperm or egg in humans
• zygote - name given to each newly formed human life, just after the gametes fuse at fertilisation
• alleles - different versions of a particular gene
• Females have XX chromosomes
• Males have XY chromosomes