genes, genotypes and phenotypes

• what is meant by a gene


  a sequence of DNA bases that occupies a specific locus
• what are the three main characteristics of genes


  they can be separated and combined, they can mutate and they code for polypeptides
• what forms of chromosomes will be found in a diploid individual


  homologous pairs
• where will each pair chromosomes come from in a homologous pair


  one from the mother and one from the father
• what is meant by heterozygous


  two different alleles
• what is meant by homozygous dominant


  the gene will contain two dominant alleles
• what is meant by homozygous recessive


  the gene will contain two recessive alleles
• What is a genotype?


  this is all of the individuals alleles that they contain
• what is a phenotype


  observable characteristics caused by the genotype
• which allele will always be expressed


  the domianant one
• what is meant by mono-hybrid inheritance


  this is the inheritance of a single gene
• give examples of phenotypes that are expressed though a single gene


  hight or seed colour
• why did Gregor Mendel use pea plants


  they are easy to grow , they can both self and cross fertilise and they produce flowers and fruit in the same year