Science Heredity Recap

• DNA


  The molecule that carries the genetic instructions for all living organisms. It is packaged into thread-like structures called chromosomes.
• Chromosomes


  Structures made up of DNA and proteins that carry genes.
• Genes


  Segments of DNA that determine specific traits.
• Alleles


  Different versions of a gene that can affect the expression of a trait.
• Genotype


  The makeup of a specific set of genes.
• Phenotype


  The physical expression of a trait.
• Dominant allele
• Recessive allele
• Dominant allele


  Represented by uppercase letters.
• Recessive allele


  Represented by lowercase letters.
• Bb = brown eyes but carry the recessive blue eye gene
• BB = Brown eyes (dominant)
• bb = Blue eyes (recessive)
• The genotype is Rr
• Genetic Vocabulary


  • Genetics
  • Genes
  • Allele
  • Genotype
  • Phenotype
  • Dominant
  • Recessive
  • Homozygous
  • Heterozygous
• Environmental factors such as diet, light and temperature can affect the expression of genes and thus the animal's phenotype
• The 28th Conference of the Parties to the UN Framework Convention on Climate Change (COP28) that UAE will host from November 30 to December 12, 2023 is important
• A Punnett square is a chart that makes it easy to find the possible genotypes and phenotypes in offspring of two parents
• The different possible combinations of alleles in their offspring can be found by filling in the cells of the Punnett square chart
• BB: 25 % Bb: 50%
• Purple: 75%
• Two tall plants (Tt) can give a short one (tt) with a percentage of 25%