Friday, 12/13/13 Please quietly take your homework out (15.1) and prepare for the Daily Quiz.

Please copy these notes! Main Idea: Genetic processes result in the continuity of life-forms over time.

Key Concepts  Common genetic structures in all species: nucleic acids (DNA, RNA) proteins  Passing genetic information: sexual reproduction (meiosis makes gametes, fertilization makes offspring) asexual reproduction (binary fission, budding, fragmentation)

For continuity of life-forms on Earth:  Species must succeed in passing genes to the next generation.  Many organisms that lived long ago resemble those still alive today!!  because heredity has passed the genetic info across generations!  all organisms share the same methods of heredity and passing traits

All life that has ever existed on Earth, share 2 structures: (1) Nucleic acids RNA or DNA carry the code for the synthesis of the organism’s proteins (2) Proteins All species, EVER: composed of the same 20 amino acids Transcription and translation is the same The same sequences of nucleotides code for the same specific amino acids.

All organisms have reliable means of passing genetic info to offspring through reproduction. Both Asexual & Sexual Repro: offspring receive essentially the same genetic information as the parent(s), but there may be some genetic variability.

Sexual Reproduction meiosis creates gametes Fertilization embryo receives alleles from each parent for each trait Offspring will express a combination of traits (variation) Genetic variability also due to gene shuffling crossing-over recombination of DNA mutations

Genetic changes or variability result in transcription and translation of new or different proteins results in changes in phenotype of individual organisms

Sexual Reproduction When it results in allele combinations producing traits that improve an individual’s chance of survival ensures the continuity (survival) of that life form (species) over time!

Asexual Reproduction involves only 1 parent that produces the offspring Offspring are for the most part genetically identical to that parent. · Examples Budding Fragmentation Vegetative propagation

Genetic variability can only occur through mutations in DNA passed from parent to offspring Through cell division: binary fission (prokaryotes) mitosis (some eukaryotic organisms use asexual repro)

Asexual Rep.Sexual Rep. Rate of reproduction Much fasterMuch slower # offspring produced Many moreMany fewer Adapted to survive current environmental conditions? YesYes, in general (except mutations, etc.) Adapted to future changes in environ. conditions?? NOT likely b/c most are genetically identical. If they don’t have the traits to survive and reproduce, whole population could die. Likely b/c lots of genetic variation (discussed earlier today)

Summary The genetic view of evolution: transfer of genetic material through these processes of reproduction. The survival of a species is contingent upon these genetic processes! And….

Summary, contd. If an organism can reproduce both sexually and asexually, they have an adaptive advantage for survival!!! Parthenogenesis in reptiles… look it up FOR BIOBUCKS!!!

Check it out! Pay attention Don’t worry about the details of the life cycle, but get the MAIN IDEA SciShow: Jellyfish (click for youtube video)SciShow: Jellyfish After the video: write a brief paragraph summary for today’s D3. Keep in your notebook.