Theme 2 Flashcards
What’s the difference between paraphyletic, polyphyletic, and monophyletic?
Monophyletic- is all sister taxa and ancestor included in group.
Paraphyletic- ancestor included in group, but not all sister taxa, one or more missing.
Polyphyletic- common ancestor not included in group.
What are Opisthokonts?
Is a clade of organisms, includes choanoflagellates, fungi, and animals
What are choanoflagellates?
A organism that belongs to the clade of opisthokonts, single celled, and paraphyletic.
In the opisthokonts, what choanoflagellates more related too?
They are more closely related to animals then fungi.
What process intially created animals?
Gastrulation
What is gastrulation? Describe it.
A process in which a digestive cavity as well as a two layered embryo forms.
The process begins with a colony of flagellate protists, then some cells begin to specialize for feeding, and then cells cave in forming the digestive cavity as well as a two layered embryo.
What are the seven features of animals (Opisthokonts), explain them.
Multicellular eukaryote
Chemoheterotrophic- eat other things to digest chemicals which they then use for energy to build molecules using organic carbon.
Cell membranes contact adjacent cell membranes (no cell walls)- cell membranes all touch at cell cell junctions.
Motile (at some life stage)- some animals are sessile, but at one point all animals were motile.
Oxidative phosphorylation to supply ATP
Sense and respond to the environment
Diploid stage is dominant (usually), haploid short lived
What three diagnostic characteristics are only found in animals (Opisthokonts)?
- Develop from a Blastula
- Have Certain extracellular matrix molecules (e.g. the proteoglycan collagen)
Have Certain cell-cell membrane junctions
What is a blastula?
When a cell develops you start of with fertilized cell that divides, becomes a hollow ball of cells and is called a blastula. All animals go through blastula stage during early development.
What is an example of extracellular matrix molecules?
molecules in/near the plasma membrane, example proteoglycan collagen.
What are cell-cell membrane junctions?
Are structures that allow contact/adhesion between cells.
What are three types of cell-cell membrane junctions? Describe them.
Tight junctions- are in vertebrates (formed by fusion of plasma membrane proteins)
Septate junctions- are in invertabraes
These two junctions keep things out
Desmosomes are leaky- allow fluid between the cells
Gap junctions allow some things to move across cells, mainly electrical current, and small molecules. Are cylindrical array of proteins that give access between cells.
Name and Describe 5 Kingdom Plantae traits
Multicellular eukaryote
Photoautotrophic (mostly)
Cell walls
Sessile
Alternation of generations life cycle
haploid (gametophyte) stage alternates with a diploid (sporophyte) stage
both are prominent/multicellular
Photoautrophic- provide food to themselves by sunlight. Each cell has a cell wall with these, has membrane and cell wall. Plants are rooted where they are growing, however stay in one place.
Plants have alternation of generations life cycle, alternated between haploid and diploid stage.
Both gametophytes and sporophyte are big and multicellular whereas ours are single celled.
What are the three sister taxa in kingdom plantae?
Green algae and landplants, red algae, and Glaucophytes (unicellular algae)
What are trace fossils?
Are foot prints/belly traces- basically signs of life tracked through mud.
What organisms developed photosynthesis? What does this mean?
Glacuocystophytes, red algae, green algae, land plants, diatoms, brown algae, dinoflagellates, apocomplexans, cercozoans, cryptophytes, haptophytes, euglenids. All came from different clades, so capture of plastids def happene dmore than once.
What’s the difference between opisthokonts and plantae (How do cells diverge)?
Cell structures are different, plant cells have everything opisthokonts cells do, except they also have a vacuole, cell wall, and chloroplasts. Plants can be photoautotrophic, animals directly can’t.
Name 3 animals that can “photosynthesize” indirectly and describe how they do it.
Elysia chlorotica- This snail eats algae that are photosynthetic and keep its in its digestive track, allows light through its digestive track and then gains energy from algae which uses light to produce products.
Spotted salamander- secretes algae into its eggs, important as it provides extra oxygen for eggs, eggs give off CO2 as waste product that feeds algae.
Corals- happens when water gets too warm and they expel symbionts which bleaches corals, the symbionts are photosynthetic organisms that are in their tissues.
How are plants mobile, what is the defintion of phototropic.
- Plants don’t need to move to get energy and carbon.
- Are sessile but can move by:
Grow up/down/laterally
Phototropic- move in direction of light
Move in response to physical stimuli ex: touch me nots)
Disperse pollen/seeds
What’s an example of plants moving?
Plants shift north as climate is warming, can see this in spruce. Sending offspring further north which allows them to move through generations.
What some consequences of animals needing to move?
Need mechanisms to be mobile, these mechanisms are derived by features such as muscles, nervous system (get you where ur going), digestive system (allows you to process food after eating, excretory system- allows you excrete waste, skeletal system- muscles need to attach to something to move, limbs- need appendage such as limbs or tentacles, allow you to work against environment, need higher metabolic rates as we move fast.
What are some examples of sessile animals?
Barnacles, coral, tube worms, mussles
How do sessile animals eat?
Filter feed, have arms that pull food, or though endosymbiosis (an organism lives inside it and brings food to it) ex: choanocyte cells bring food to sponges.
Do sessile animals have a head?
All don’t have a developed sensory sytem, sessile organisms tend to be missing heads as they have no need to search for food. Food is obtained near them.
