Lecture #1: Introduction to Genetics and Cells Honors Genetics Ms. Day

What is Genetics? the study of how genes act to produce characteristics of a living organism. This course will be divided into 3 areas of study: molecular genetics how DNA encodes traits classical genetics how traits are inherited genomics how all an organism's genes function and interact.

Central Dogma of Biology Where does it all START? Central Dogma of Biology TRAIT

Did you know? Scientist named Mendel 1st started studying genetics in 1800’s. BUT…DNA’s structure was discovered in 1953. Study of heredity called GENETICS quickly evolved Discovery of DOUBLE HELIX launched era of Molecular Genetics & Biotechnology 

How do scientists study Genetics? Use MODEL ORGANISMS An organism whose genetic material has been altered by genetic engineering techniques Criteria to be a model: easy to grow short life cycle produce many offspring relatively inexpensive easy to manipulate/mutate Used by “KNOCKING OUT” or “TURNING OFF” genes then look for consequences

What are some common MODEL organisms? E. Coli bacteria Yeast Nematode (round) worms called C. elegans Fruit Fly called Drosophila melanogaster Common Mouse

CELL TYPES Three Basic types of cells include: Animal Cell (Eukaryote) Plant Cell (Eukaryote) Bacterial Cell (Prokaryote) **SMALLEST

I look BIG here, I’m very small (1 cell). NUMBER OF CELLS ALL living things are made of cells! organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize into tissues, etc. I look BIG here, I’m very small (1 cell).

MULTICELLULAR ORGANISMS Cells in multicellular organisms often specialize (take on different shapes & functions)

CELL SPECIALIZATION Cells in a multi-cellular organisms become specialized by turning different genes on and off This is known as DIFFERENTIATION

ALL CELLS… Contain 4 basic cell structures: Cell Membrane Cytoplasm Ribosomes DNA

PROKARYOTES: THE FIRST CELLS Simplest and smallest type of cell Ex: bacteria NO nucleus FEW organelles 1 Single, circular chromosome (piece of DNA)

THINK: “You carry a lot…of stuff” EUKARYOTES All eukaryotic cells HAVE: a Nucleus membrane-bound organelles These cell types includes: protists fungi plants animals More complex type of cells THINK: “You carry a lot…of stuff”