DNA and Inheritance

• What is DNA

  Is a double stranded polymer of nucleotides that form a double helix
• What does DNA do?

  Protein so it codes and makes protein
• What does each strand of DNA consist of?

  Alternating sugars and phosphate molecules
• What are the 4 bases

  • A - adenine
  • T - Thymine
  • C - Cytosine
  • G - Guanine
• What base pairs with what base

  C pairs with G

  T pairs with A
• What is a gene

  A section of DNA that codes for a protein
• Triplets

  A sequence of three bases in a gene forms a triplet. Each triplet codes for an amino acid. Order of amino acids determine the structure and function of the protein formed
• What is genetic profiling?

  Is a method of comparing DNA
• Method of Genetic Profiling

  1. Sample of cells collected
  2. DNA extracted from cells
  3. DNA sample cut into fragments using enzymes
  4. Fragments separated into bands, creating a genetic profile
• What can genetic profiling be used for?

  • Paternity Testing
  • Forensics
  • Classification
  • Detecting Genes
• What a gene?

  A length of DNA that codes for the production of a particular protein
• What a Allele?

  A version of a gene
• What is a Gamete?

  Reproductive cells that contain a single copy of each chromosome
• What is a dominant?

  Describes an allele that is always expressed. Represented with a capital letter
• What is a Recessive?

  An allele that is only expressed in the absence of a dominant allele. Represented with a small letter
• What is a Homozygous?

  Having two identical alleles of a gene e.g FF
• What is a Heterozygous?

  Having two different alleles of a gene e.g Ff
• What is a Genotype?

  An organisms genetic composition describes all alleles
• What is a Phenotype?

  An organism observable characteristic
• What is a F1 generation?

  First generation in a genetic cross - the offspring produced when two organism interbreed
• What is F2 generation?

  Second generation in a genetic cross - the offspring produced when two organism from the F1 generation are bred together
• What is a selfing?

  An artificial method of self pollinating plants
• Who first discovered Genetics?

  Gregor Mendel (1800s)
• Diagram

  Diagram:

  
• Dominant and Recessive Alleles

  In the body cells, chromosomes occurs in pairs. This means that the genes on them also occur in pairs.
• Example of Dominant and Recessive Alleles

  For example a pair of chromosomes may each contain a gene that code for eye colour. The different forms of genes are called alleles. In a pair of alleles, one may code for blue eyes and one may code for brown eyes. Alleles are simply different forms of the same type of gene.
• Dominant Alleles

  In most cases one allele is dominant over the other and always hides it. The allele is hidden is called the recessive allele. Because of this recessive alleles are rarer than dominate ones.
• Dominate alleles in leopard

  In coat colours of leopards the spotted form is dominant to the black form. So the black form is recessive. For this reason the normal spotted form of leopard is much more common than the black for or panther
• Single gene inheritance

  Most characteristics of an organism are determined by multiple genes interaction, however some are determined by a single gene
• What is Monohybrid Inheritance?

  What is the inheritance of a single gene
• What do you use a pundit square?

  Can be used to illustrate the single gene inheritance
• Examples of Pundit Squares

  Examples

  
• Examples of Pundit Square

  Questions

  
• Sex determine in humans

  Sex chromosomes are one of the 23 pairs of chromosomes that determine sex
• What are male chromosomes

  X and Y
• What are female chromosomes

  X and X
• Sex determine

  Diagram

  
• What is genetic modification?

  The process of taking a gene from one organism and inserting it into another
• What characteristics might scientists introduce to crops when they genetically modify them?

  • Resistance to pest
  • Resistance to herbicide
  • Resistance to draught
  • Contain more nutrients
  • Ripen early
• State the most common use of genetic modification

  Farm animals, crops and bacteria