Inheritance

• Genes from the father are inside the sperm nucleus, and genes from the mother are inside the egg nucleus.
• Nucleus contains thread-like chromosomes. These carry the genes that control characteristics. Total of 46 chromosomes. 23 from Mum and 23 from Dad. Arranged in pairs.
• Chromosomes are made up from DNA that codes for a protein.
• DNA - Deoxyribonucleic Acid
• DNA - Ladder-like structure. Four Bases:

  A (adenine)

  T (thymine)

  C (cytosine)

  G (guanine)
• Proteins are made from 20 different amino acids, found in the cytoplasm. It is the order of the bases that decide the order of amino acids.
• Each amino acid is coded for by a sequence of 3 bases in the strand of DNA. Every 3 bases form a triplet code.
• DNA Structure:

  1. Double helix structure
  2. Made out of sugar
  3. Phosphate backbone
  4. Complementary bases
• Genetic Profiling is the process of determining the genetic makeup of an individual. Can identify suspects from evidence at a crime scene. Used in paternity cases. Used for comparisons between species for classification.
• The DNA in your cells is unique, unless you have an identical twin.
• Genetic Profiling Stages:

  1. Isolation - Separate DNA from the cytoplasm of cells.
  2. Fragmentation - Enzymes are used as chemical scissors to break DNA into short lengths.
  3. Separation - DNA fragments placed in a well one at a time with a layer of gel. An electrical current will separate fragments according to size.
  4. Comparison - The patterns of the fragments on the gel are compared to other DNA
• Haploid - 1 set of chromosomes

  Diploid - 2 sets of chromosomes
• Every cell nucleus has two of each type. Normal body cells have 46 chromosomes in 23 pairs
• Reproductive cells reproduce sperm or egg cells which are also known as gametes
• Egg + Sperm = Zygote = Embryo
• Boy - Y

  Girl - X
• Male - XY

  Female - XX
• Alleles - Two forms of the same gene, and we use letters to represent them
• Genotype - The genetic make-up, i.e. your alleles (pair of letters)
• Phenotype - The characteristic that is shown because of your genotype.
• Dominant Allele - Allele will always show in the phenotype when present. (Capital letter)
• Recessive Allele - Will be hidden when a dominant allele is present. (Lower case letter)
• Homozygous - Two alleles for a gene are identical.
• Heterozygous - Two alleles for a gene are different.
• Genetic modification is the artificial transfer of genes from one species to another.

  Adv - Disease resistant

  Disadv - Effect environment
• GM crops increase yields and are useful for feeding a growing population. Some believe it is unethical and should be banned