7.5.3 Natural Selection and Evolution
Life on Earth has been around for over 3 billion years. (Who knows how long it has existed elsewhere in the universe?) Starting from the smallest unicellular bacteria billions of years ago, life has adapted and evolved into wondrous forms of unimaginable beauty and diversity. Looking at the existing species of the world is only a glimpse to the 99% of extinct creatures that have once inhabited this Earth, from the dinosaurs to our ancient primate relative, Ida.

How does life change and adapt over time, to eventually create new creatures and new classes of animals? Through natural selection, where the fittest survive and beneficial mutations are passed on to the offspring.

Check out more information at:

http://www.wellcometreeoflife.org./interactive/
http://www.pbs.org/wgbh/evolution/library/03/4/l_034_02.html

Games and Simulations:
Evolution Lab
http://biologyinmotion.com/evol/index.html
Evolution Quiz
http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/environment/evolutionact.shtml
Guess the Embryo
http://www.pbs.org/wgbh/nova/beta/evolution/guess-embryo.html

7.5.2 Genes and HeredityWhy do you look a little like your mom, and a little like your dad? How come some traits skip generations? Why can't Mr. Lee ever have a green eyed baby with Mila Kunis? I know these questions keep you up at night, so learn about genes and heredity to figure it out!

Dominant and recessive alleles, genotypes and phenotypes, inherited vs. learned traits (nature vs. nurture), Punnett Squares, homozygous and heterozygous genotypes, there are lots of new terms you must know to fully understand genetics.

But the short of it all is, we inherit genes (on chromosomes) from each of our parents. That determines most of who we are!

Activities:

Making Punnett Square: http://www.siskiyous.edu/class/bio1/genetics/monohybrid_v2.html

Genetics WebLab Directory: http://www2.edc.org/weblabs/WebLabDirectory1.html
(Try out the Mendel's Peas and Punnett Squares)

Genetics (The University of Utah): http://learn.genetics.utah.edu/

Play the "DNA-The Double Helix" replication game!
http://nobelprize.org/educational_games/medicine/dna_double_helix/dnahelix.html

Dog Breeding
http://pbskids.org/dragonflytv/games/game_dogbreeding.html

Human Genome Project
http://ghr.nlm.nih.gov/BrowseGenes

7.5.4 Body Structure AdaptationsAll living creatures need to satisfy the six basic needs of life: get food, get water, protect themselves from the environment, protect themselves from other organisms, get air (oxygen), and reproduce.

Every single body structure adaptation and behavior must help the organism satisfy one of these basic needs of life. For example, a turtle's shell has evolved over millions of years to help them protect themselves from their predators and a whale's blowhole helps it obtain oxygen easily when it surfaces.

Check out these other strange animals and note their peculiar body structure adaptations. (The one above is the axolotl from Mexico.) What basic needs are satisfied?

http://webecoist.com/2009/02/03/the-9-strangest-animals-on-earth/

http://listverse.com/nature/top-10-strangest-animals/

http://webecoist.momtastic.com/2009/12/21/15-rare-exotic-amazing-plant-species/

Mitosis!

Here is what mitosis looks like:

Here is the Brainpop.
http://www.brainpop.com/science/livingsystems/mitosis/

Video from Twilight!
http://www.youtube.com/watch?v=sOM_u1PY0s0

Asexual and Sexual Reproduction (7.5.1)Organisms have two ways of reproduction: asexually (one parent) and sexually (two parents). Both have their benefits and dangers.

Asexual reproduction (having one parent from which 100% of the DNA is transferred) includes fission (bacteria), mitosis (eukaryotes), regeneration, potatoes and banana suckers. It's fast, no need to find a mate, and the good genes are guaranteed to be passed on. However, the bad genes are also passed on, and the lack of genetic diversity becomes a problem (more about this as we learn about bananas).

Sexual reproduction (having two parents from which 50% of the DNA is transferred from each) includes an egg cell (mother) and a sperm cell (father). We'll cover fertilization, parrotfish populations, and meiosis. Genetic diversity is ensured, but time and energy is needed to find a mate.

Strange Mating Rituals!
More Strange Mating Rituals
Zoo Matchmaker

YouTube Videos:

Asexual Reproduction:
Bacteria Fission
Mitosis

Sexual Reproduction:
Sea Horse
Praying Mantis