Genetics plants and organisms study guide.txt

4.5-5 Bil years old

RNA

• no nucleus
• no membrane bound organelles
• circular chromosome
• circular DNA

• has nucleus
• has membrane bound organelles
• linear chromosomes
• larger ribosome (80S) vs prokaryotes

Idea that mitochondria and chloroplasts were once free floating organisms BUT then were engulfed into eukaryotes

• 1. RIBOSOMES (70S ribosomes in mitochondria & chloroplasts as seen in prok)
• 2. STRUCTURE (mitochondria & chloroplasts similar structure to prok)
• Both have their own DNA and have CIRCULAR chromosomes

• multicellular organisms ~1bil yr (in water)
• then plants released O2 to produce O3 which protects from UV radiation, aiding evolution of things on land
• then humans

• 3.2BIL bps
• 23chromosomes
• haploid = 23 (# of chrom in sperm or egg)
• 2n = 46 (somatic cells have 46 chrom)

• Mus musculus
• Diploid 2n = 40chromosomes
• 99% homology w/humans
• seq 2002

• Drosophilia
• 50% homology w/humans
• LOTS of mutants
• 1 female has lots of eggs
• 2n = 8
• seq 2000

• C elegans
• can visualize exact DIVISION patterns cuz its see thru
• 25% homology to humans
• 2n = 10 (5autosomes)
• seq 1998

• S cerevisiae
• n=16 chromosomes
• 25% homology to humans
• 2 mating types: schmoo (sexual reprod..genetic exchange due to receptor signaling, then split apart into haploid again) and budding
• seq 1996

• 2n= 10
• LOTS of mutants
• similar protein fxns in animals and plants
• seq 2000

• female:
• Meiocyte goes thru meiosis and only 1 of 4n survive
• mitosis occurs and result is: MEGASPORE mother cell
• fertilizes with the sperm and 2n + sperm n = 3n endosperm (1n from dad, 2n from mom)
• endosperm provides nutrients for embryo to grow!
• male:
• meiocyte goes thru meiosis and all 4n sperm survive
• mitosis occurs and result is: MICROspore

• contains 2 haploid sperm cells
• 1 used to fertilize egg nucleus (create 2n diploid embryo)
• 1 used to fertilize 2 polar nuclei (creates the endosperm, provides nutrients for embryo growth)

• contains:
• egg nucleus (n), which is fertilized by one sperm (n) = 2n
• 2 haploid polar nuclei (n), which fertilized by one sperm (n) = 3n