Biology Unit Test 1 - 1.3
Fungi
(characterized by eukaryotic, multicell, heterotrophic, and cell wall with chitin) Ex. Mushrooms, molds, and yeasts Multicellular - exception: yeast single-celled (only exceptions) Heterotrophic (absorption) *they don't do photosynthesis. Mushrooms feed on already built organic molecules (why you see them growing on a fallen tree) - decomposers Cell walls - made of chitin (not made of same type of molecules that we see in a plant cell wall)
Cells are typically no larger than...
100 um (to view a single cell you would use a light microscope)
Phylogentic tree: Fish
2 groups - cartilaginous v. Bony. Cartilaginous - have a skeleton but its made of cartilage (sharks, sting Rays, etc.) humans have it on their nose, ears, and between joints Bony - like gold fish, trout, sea horses...
Evolution in the protist kingdom created:
3 other Eukaryotic Kingdoms, the Fungi, Plantae, and Animalia
Multicellular Organism
A cluster of small cells of the same total volume maintains a larger surface area
Common Multicellular Protists
Algae (many types) - kelp, seaweed, lake algae. There are even green and red Algae. PROTISTA GAVE RISE TO FUNGI, PLANTAE, and ANIMALIA !!!Kelp aka brown algae is the largest protist!!!!
3 Common Unicellular Protists
Amoeba - Pseudopods, heterotrophic Euglena - flagella, mixotrophic Paramecium - Cilia, heterotrophic ALL THREE LIVE IN WATER
Amphibians v. Reptiles
Amphibians aren't amniotes They require water Reptiles are amniotes They don't require water Eggs are protected from drying out because they have a shell
Chitin is also found in...
Athro pods (animal kingdom like insects) in the exoskeleton
Reptiles are...
ECTOTHERMIC - use behavior and environment for thermoregulation (can't generate own) - not "cold-blooded" - ex. a lizard needs to maintain body temperature at 88F They'll change environment for Homeostasis of thermoregulation to keep body temperature But they have to do this based on behavior. - if too cold - bask on warm rocks, take a swim
Monotreme -
Egg laying mammal
All protists have...
Eukaryotic cells
Cell size from biggest to the smallest
Eukaryotic, Prokaryotic, Virus's (cell function limits cell size)
Protista
Eukaryotic; the first multicellular organisms to evolve (most diverse group of kingdoms)
Plantae
Ex. Moss, ferns, cone-bearing, flowering Autotrophic and multicellular Cell walls - made of cellulose All plants --> sexual reproduction (some can do asexual in addition to sexual but it isn't their "primary" mode of reproduction) All these plants are autotrophic, being able to do photosynthesis
True or False - We were the first organisms to get to land
False
True or false - all mammals have live birth (it is one of our class' defining characteristics)
False
T or F - Life stayed in water
False, some life moves to land, some stays in water
Why move to land?
Fewer predators and new and empty niches (habitat and role). Too much competition in the water --> moving to land that has new places to live, called ecological niches. BUT you CAN'T just live on land because you want to, you need specific traits because land was very hot/dry compared to the water
Chordata Phylum Evolution:
Fish, Amphibians (movement on land), Reptiles---Birds, Mammals
3 multicellular Eukaryotes (evolved from protista kingdom)
Fungi Plantae Animalia
Fungus types...
Fungus-like Protists: gave rise to the fungi kingdom Some animal like: like the amoeba Some plant like protists: that perform photosynthesis - arose by endosymbiosis of cyanobacteria
Fungi and Animalia are both...
Heterotrophic
Special group of bony fish...
Lobe-Finned Fish Many extinct. Not only have skeleton of skull/backbones, but also in their fins. They're called lobed fins because they have much thicker fins as apposed to a typical goldfish for instance that has a flimsy fin w/no bones in it. They are the first with bones in their fin Rod shaped Used their obed fins to "walk" underwater, and swim (setting up for evolution of having four limbed w/bones for walking around)
Mammals 3 major taxa
Monotremes Marsupials Eutherians
The First Land Dwellers
Plants and Arthropod Animals (ex. insects)
Birds are an offshoot from...
Reptiles
Ectothermic differentiates...
Reptiles from birds and Mammals
Amphibians
Salamander, frog, toad, and caecilians - still have ties to water (even though they live on land, they need water for their reproduction. Eggs are jelly like which would dry out if not in water) -eggs are jelly- like(like fish) - Baby lives in water until metamorphosis -Breath through their moist skin (needs to keep skin moist or else they can dry out and die) they breath through their skin and need moisture to help them to get oxygen into their bodies
Amphibians
Spend lots of time in water because they need water as part of their life cycle for reproduction to live but yet they can also spend some time on land, like a frog (they are the first tetrapod's)
Animalia
Sponges, coral, worms, insects, fish, birds, reptiles, mammals ALL ARE HETEROTROPHIC and MULTICELLULAR No cell walls!!! (only plasma or cell membrane) Sexual reproduction (some can do asexual) Motile (mobility; able to move) Rapid response to stimuli
Smaller objects have a larger ratio of...
Surface Area to Volume (good for cells)
Everything amphibians and on is a
Tetrapod - evolved from a lobe-fined fish ancestor! in addition to living on land without needing water was the amniotic egg (important to land living)
When discussing the evolution of moving to land in terms of chordate phylum, it the term...
Tetrapod meaning four-limbed animal - including all amphibians, reptiles/birds and mammals (extant and extinct)
T or F - The smaller the cell, typically is more efficient
True
Evolution of Multicellular Organisms:
Unicellular --> Colonial living --> Multicellular - First was a colonial algae --> multicellular algae - Soft bodies aquatic animal (very basic primitive animals) --> sea sponge (They're multicellular organisms, and there was a colonial ancestor that then before that of course there was some single-celled ancestor as well) Multicellular life had to come after we got the first Eukaryotes
Types of Protista
Unicellular like the amoeba Some single celled in a colony that work together Some are multicellular like seaweed Some are plant like and do photosynthesis, and are autotrophic like seaweed There are some that even eat other protists (heterotrophic) Some are both autotrophic and heterotrophic, which is mixotrophic Some have sexual reproduction, some asexual (led to evolution of plants, animals, and fungi, which are multicellular)
Birds have...
amniotic eggs. They are of reptile lineage that adapted scales into feathers for flight - Unlike other reptiles, birds are endothermic meaning that they can GENERATE heat by their metabolism to maintain homeostasis (like mammals)
The increase of the cell size...
decreases the ratio of surface area to volume making the cell LESS EFFICIENT - the surface area won't be big enough to diffuse molecules across to sustain the volume of the cell -Molecules can't move within the cell quick enough
Mammals have....
hair mamary glands (name comes from this): Allows mammals to produce milk for the baby to drink They are Endothermic "The evolutionary transition between single-celled organisms and multicellular organisms is called colonial, and came about in the protista kingdom"
In order to solve this problem of wanting to get larger, the solution is...
having a large organism made of many cells, or multicellular life. We get a good ratio when breaking a large organism into many single cells *multicellular life came about in protists
IF THE CELL IS TOO BIG...
its' not going to be able to survive (can't move things around in and out of the cell)
Mammals
last major group in chordata, we have a common ancestor with reptiles as mammals
Being Endothermic allows you to...
live in many places on the planet. Endothermic animals need to eat a lot to get many many calories, compared to a reptile or an amphibian
Examples of Reptiles
lizards, snakes, turtles, crocs, dinos - 1st fully terrestrial (first to break ties with water) due mainly to the development of the amniotic egg Eggs are now hard sheeld which protects baby from drying out when developing
Cell size
multicellular organisms have to be a specific cell size Just the activities they do to stay alive put a requirment on the cell size: they have to be relatively small
Birds
offshoot of reptiles, which is why they don't have their own stem, but connected to the reptile stem
Eutherians -
placental mammals - complete develop of young in mother's uterus attached to placenta (exchanges nutrients between mom and offspring) - Still amniotic! - babies develop in fluid surrounded by amniotic sac
Marsupial -
pouch mammal Brief gestation followed by birth of tiny embryo into pouch for further development
Metabolic requirments:
set a limit to the size of a single cell - all cells are very small
Chordats are eventually going to reach land (human phylum). WE weren't...
the first organisms to get onto land
Reptiles
the first true terrestrial land dwelling chordates
Colonial
the step before multicellular; this is when we have many single-celled organisms to live in a colony together these are one of the precursors to true plants: Volvox, which is a type of green algae ("Globe Algae").
Fish were the first...
vertebrate members having bones, spinal cord, and spinal backbones encasing our spinal nerve cord
Fish are important because...
we want to look at the transition from fish, to amphibian, that has bones in their legs and can eventually get on to land as a reptile