Genetics

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Genetics
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Whats it all about?
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Questions what we will answer.

• What is genetics?
• How do chromosomes work?
• What is the history of genetics?
• Genetics and probability What are Punnett
  Squares?
• How does the study of genetics affect our lives?
• What is the future of genetics?

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Genetics is the science of heredity.

• Heredity - the passing of traits from parents to
  offspring.
• Traits - characteristics or features of an
  individual, not always apparent or obvious

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Chromosomes the mechanisms that make it all
possible

• Chromosomes are in pairs, found in the nuclei of
  cells.
• A single chromosome is composed of many genes,
  which determine hereditary traits.
• Chromosomes are made of a molecule called
  deoxyribonucleic acid (DNA).
• Human cells contain 46 (23 pairs) of chromosomes
  totally about 35,000 genes on them.
• There are 2 to the 23rd power (or 8,388,608)
  possible gene combinations.
• Gametes (sex cells sperm and eggs) contain only
  half the number of chromosomes.

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Chromosomes are made of DNA. Segments of
chromosomes are called genes.
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Deoxyribonucleic Acid (DNA)

• The double helix shape resembles a spiral
  staircase.
• The shape was first correctly identified in 1953
  by James Watson and Francis Crick, who then won
  the Nobel prize in 1962.
• The unique shape allows the molecule to unfold
  or unzip along a portion of the molecule.
• When a strand of DNA unzips, an exact copy of
  the unzipped portion can be replicated (copied)
• DNA replication is how cells make proteins, which
  build new cells, repair cells, and many other
  functions that keep the cells functioning.

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DNA replication (making copies)

• The unique shape of DNA allows the molecule to
  unzip along a portion of the strand.
• When a strand of DNA unzips, an exact replica
  of the unzipped portion can be replicated
  (copied)
• DNA replication is how cells make proteins, which
  build new cells, repair cells, and countless
  other functions that keep cells functioning.
• DNA replication is happening constantly in cells.