Bio 2 Lab - Midterm Flashcards
What is a phylogenetic tree?
A diagram that shows the hypothesized evolutionary relationship among species.
What is a clade?
a group of organisms that share evolutionary characteristics.
What is divergent evolution?
Shared evolutionary characteristics (inherited from a common ancestor) can be modified through natural selection in different organisms.
What are homologous structrures?
Modified characteristics inherited from a common ancestor.
What is convergent evolution?
Some disparate evolutionary characteristics (inherited from different ancestors) can change over evolutionary time to look similar or perform similar functions.
What is a homoplasy?
A similar trait that is found in two (or more) distantly related species,
What is parsimony?
When scientists construct a tree based on the simplest possible evolutionary path.
What is a polyphyletic group?
a group of taxa that includes distantly related species but does not include their most recent common ancestor.
What is a monophyletic group?
Includes a common ancestor and all of its descendants.
What is a paraphyletic group?
a group of taxa that includes distantly related organisms but does not include their most recent common ancestor.
What are prokaryotes?
Organisms that lack membrane-bound organelles.
What are the two types of prokaryotes?
Archaea and Bacteria
What are the three domains of life?
Archaea, Bacteria, and Eukarya
What are Eukaryas?
Protists, fungi, plants, and animals.
Most Archaea are extremophiles, true or false?
True
What are the cell walls of bacteria made up of?
Peptidoglycan
What is gram-negative?
Bacteria that has a thin peptidoglycan layer with an outer membrane.
What is a gram-positive?
Bacteria that has a relatively thick peptidoglycan layer with no outer membrane
Archaea have peptidoglycan in their cell walls, true or false?
False
Where are cyanobacteria found?
freshwater, marine, and terrestrial habitats.
How do cyanobacteria gain energy?
Through photosynthesis, they capture light energy and use it to convert water, carbon dioxide, and minerals into oxygen and organic compounds.
What are the main cyanobacteria?
- Anabaena sp.
- Merispmopedia sp.
- Oscillatoria sp.
- Rhodospirillum
What does anabaena sp. look like?
Form chains
What does Merismopedia sp. looke like?
Spherical bacteria that form grid-like sheets
What does Osillatoria sp. look like?
Filamentous
What color is gram positive?
Purple
What color is gram negative?
pink
What is the mucilaginous sheath?
Sometimes surround cyanobacteria that is jelly-like and made up of glycoprotein to cover and protect the cells.
What are heterocytes?
specialized cells with the ability to fix nitrogen
What are akinetes?
thick-walled dormant cells specialized for survival.
What are protists?
A group consisting of all eukaryotes NOT classified as an animal, plant, or fungi.
What are the three main groups of protistis?
Ciliates, Flagellates, and Sarcodinids
What are Ciliates?
A large group of protists named after their use of cilia to move and feed.
What are flagellates?
Protists named for their use of flagella.
What are Sarcodinids?
Protists that move using pseudopodia or false feet.
What are Eukaryotes?
Organisms with complex cell or cells, whose genetic material is organized into a membrane-bound nucleus or nuclei.
What is Endosymbiosis?
A hypothesized process by which prokaryotes gave rise to the first eukaryotic cells.
What is primary endosymbiosis?
The engulfment of a bacterium by another free-living organism.
What is secondary endosymbiosis?
When the product of primary endocytosis is itself engulfed and retained by another free-living eukaryote.
What is the reasoning behind the name of Supergroup Excavata?
They have a feeding groove seemingly excavated from the cell surface.