Flashcards in Test 1 Deck (51):
Know what gasses were present in the earth’s atmosphere before 2 bya. Know relative proportions (p 508)
Gasses that were present: nitrogen (N), carbon dioxide (CO2), methane (CH3), ammonia (NH3), hydrogen (H) , and hydrogen sulfide (H2S).
· Proportions: Low O2, High N and CO2
Know what autocatalytic RNA molecules are (p.509)
RNA that self replicated and could catalyze
Where was the first hereditary information found? (p. 509)
RNA, it can carry genetic info and also be autocatalytic
Why would the evolution of life switch to DNA to carry the genetic code? (p. 510)
Switched from RNA to DNA b/c DNA is more chemically stable and replicates with fewer errors
What allowed earth’s early chondrites to survive and also allowing the earth’s original amino acids. Know what the source was (p. 509)
The early atmosphere was dense, slowing down the chondrites which contained at least 80 different amino acids
Determining absolute dates by radiometric dating requires what things? (p. 512)
Accumulation of daughter isotopes; loss of parent isotopes
What role did cyanobacteria play in earth’s development? (p. 516)
Cyanobacteria contributed the most to developing the earth’s early atmosphere; made oxygen later it’s why the atmosphere is what it is
What event took place at the end of the snowball earth period? (p. 517 – 518)
The Cambrian Explosion – accelerated growth of life
How far back does the body fossil record go? (p.514, Fig 25.7)
What effects or causes does 2 continental landmasses have when they converge? (p. 520)
Global Climate Change
· Change of ocean currents and wind patterns
· Net loss of inter-tidal zones and habitats
· Extinction of many species
In regards to morphology, how would Linnaeus classify organisms differently than modern biologists would
Linnaeus would have classified the Hawaiian sliver swords as multiple species
What would you expect from an organism with a large number of hox genes?
Hox genes are responsible for the growth of body parts, where they grow, and how big. If you have more hox genes you will be more complex organism. Provides positioning information
Know what Homeotic genes are (p. 526)
Basic features of positional information hox genes are type of homeotic genes
Understand the roles that different anatomical features may have.
For example: feathers were used for warmth before they were used for flight. Or that a lung can be used as a swim bladder when fish evolve. Lung changed into swim bladder in fish. This is called EXAPTATION
What does exaptation mean?
When a body part is utilized for a new purpose than it was before
Know why plants, fungi, and prokaryotes are placed in different Taxa (p. 557)
Their cell walls are made of different stuff
Where is peptidoglycan most commonly found?
Gram + bacterial cell walls, gram + has more peptidoglycan and gram- less peptidoglycan
What is plasmolysis?
When the cell membrane pulls away from the cell wall due to loss of water
sugar will lyse the cell wall of bacteria.
What are the unique characteristics of endospores? (p. 560)
They can survive harsh climates for long periods of time. BUT endospores are NOT present in all bacteria. They are also immune to acidity.
Understand and know what structures/processes are involved in conjugation
Sex pili and stuff
. Know what is produced by Gram – bacterial cell walls
Only in gram negative ENDOTOXINS are released
Know the characteristics of cyanobacteria (p.589, 564)
· Photoautotrophic (photosynthesis)
· Nitrogen fixation
What are ways that prokaryotes protect an enzyme from oxygen? (p. 564)
· Capsules – form capsules to protect
· Obligate Anaerobes – live with out air
What is horizontal gene transfers?
The mitochondria acquire their genes because they are descendants of the Prokaryotes
Characteristics of bacteria lacking peptidoglycan (archae).
· They have an optimal pH that is less than 7.0,so they like an acidic environment
Understand sign between peptidoglycan and a thermoacidophyle
One is Archaean and one is a hot acid
Know and understand why prokaryotes have been so successful on earth
· Large Biomass
· Reproduce Quickly
· More diverse habitat
· More diverse metabolism
What is the danger of over-use of antibiotics?
Bacteria will evolve bacterial resistance
How would a host respond to a broad sense of antibiotics?
Know how intestinal bacteria play a role in our nutritional absorption
Produce vitamins and protect us
Know that protists are Eukaryotes
What are some examples of strong evidence that there are endosymbiotic organisms in eukaryotes? (p. 578)
Know what a mixotrope is and what allows it to survive
They combine photosynthesis and heterotrophic nutrition. So if a mixotroph loses its plastids it can still survive by eating other organisms. Mixotrophs survive by phagocytosis and absorption.
Know a list of bacteria and which would be able to avoid the immune system?
Trypanosome – hide inside cells change antigens,sleeping sickness
· Plasmodium – Malaria
· They can evade the human immune system by changing their surface proteins
What are dynoflagellates? (p. 582)
· They make the red tide
· Have 2 flagella
· Walls composed of cellulose plates
· Many types contain chlorophyll
What are ciliates? (p. 584)
· Use cilia for locomotion
· They are complex organisms
· Primarily live in fresh water
· Have 2 or more nuclei
. Understand why convergent evolution is taking place between the water molds and fungus hyphae
Common need for the decomposers to absorb nutrients by increasing surface area through hyphae (long projectiles)
Know what caused the Irish Potato famine
Oomyctes (water/Slime molds)
What is Silica and where is it found most
Marine sediments consisting of radiolarian shells; built on silica backbone (CLIFFS OF DOVER); They are found in Diatoms
Know what Foraminifera are (p. 589)
Protists, eukaryotic, tests or porous shells and have pseudopodia that extend and function in swimming, test formation, and feeding.
Absorbs blue and reflects red
A-Know how colors are projected and how that pertains to algae (p. 590)
Coloring is what they reflect
What is Brown Algae?
The largest sea weeds belong to brown algae. They are the most abundant
. Know the 5 (or so) main points about protists.(p. 595, 594)
Extremely diverse collection, photoautotrophs,heterotrophs, mixotrophs, so diverse because of endosymbiosis
Know the general characteristics of fungi.Know what they do, and how they absorb food
Decomposers, they throw up/ secrete hydrolytic enzymes and then absorb nutrients. Cell wall composed of chitin
Know what the fungal enzymes do.
They secrete enzymes through hyphae hydrolytic enzymes and then absorb nutrients
Know groups or phylum that have protective chitin shells or coverings (p. 637)
Arthropods, Insects, Fungi
Know what hyphae are as they pertain to fungi
Projections that create mycillium, and secrete hydrolytic enzymes, Underground
Know what pheromones are and what roles they play. (p. 639)
Pheromones are sexual signaling molecules
Know what chytridiomycota is (p. 641)
This is the phylum that contains organisms that most closely resemble the ancient fungi and there are a ton of them