Wednesday, September 13, 2017
Biology 1201a
Lecture #1- Diversity of Life
- Earth is the only known planet to harbour life
- All life is defended from a single common ancestor (called last universal common
ancestor, LUCA)
- The further you go back, eventually you will be related to every living thing on this
planet, including bacteria
Homo Sapiens
- Part of a group called primates
- Closely related to chimpanzees
- We are mammals, closes relatives are rodents (ex. beaver)
- We are vertebrate (have a back bone, spine)
- Chordates (have a nerve cord but no boney structure (spine) )
- Deuterostome - anus develops from blastopore, mouth from second opening (star
fish)
Animal
- Motile (at some point in their life)
- Heterotrophs - oxidize organic molecules for energy (ex. carbs, sugars, fat)
- Depend on other life forms for food (unlike plants)
- Require oxygen
- Eukaryotic, multicellular organism (comprised of 10 trillion cells aka multicellular)
- One cell can not survive on its own, it depends on other cells in the body
- Human skin has epidermis on top with dermis underneath
- Nucleus houses you DNA, DNA is also in the mitochondria
1
Wednesday, September 13, 2017
Human Genome
- 46 chromosomes consisting of linear double stranded DNA
- 23 chromosomes, 2 of each
- = 3,200,000,000 nucleotide base pairs
- Mitochondrial genome, each mitochondrion contains 1 chromosome (circular dsDNA)
= 16,569 nucleotide base pairs
Fungi
- Multicellular eukaryotes
- Have spores that come out by gills and are c carried by wind so they spread
- Heterotrophic, by absorption, often decomposing dead plants/animals
- They do not consume carbs they absorb them from the outside of the cell and bring
them in
- They are decomposers
Plants
- Multicellular eukaryotes
- Most are photoautotrophs (via photosynthesis)
- Use light energy to produce carbohydrates from CO2
- Have cell walls, are non-mobile
- Have a large vacuole
- They have a chloroplast (organelle that captures light and uses that energy to make
carbohydrates)
- In plant cells the chloroplast also has DNA
Seaweeds
- Multicellular eukaryotes
2
Wednesday, September 13, 2017
- Most are photosynthetic
- Have cell walls
- non-motile
- but are NOT pants (aquatic, do not make embryo/seed that develop within parental
gametophyte)
Is That It?
- Does that natural world only consist of animals, plants, fungi, seaweed, minerals
- There is life on this planet that you cant see
- People thought animals sound be placed higher up because they have a “higher
affinity for energy” because they can move
Animals
Fungi
Plants
Seaweed
Multicellular?
Yes
Yes
Yes
Yes
Motile?
Yes
No
No
No
Carbohydrate
Storage
Glycogen
Glycogen
Starch
Lamination
Seeing is Believing
- Existence of microorganisms - not proven or observed until the invention of the
microscope in the 17th century
- Antonie van Leeuwenhoek was an early inventer microscope
- He observed “animalcules” in pond water
- Robert Hooke’s microscope observed and coined the term cells
3