Exam 2 Flashcards
What is the prebiotic soup hypothesis?
Organic molecules formed near earths surface
What are the four requirements for Chemical Evolution?
Little to no oxygen
Source of energy
Chemical building blocks
Time
What is the iron-sulfur world hypothesis?
Organic precursors formed at the cracks in the oceans floor
What is a protobiont?
The first cells-
What was most likely the first molecule of life?
RNA
What happens in the Precambrian era?
Life forms, we have the introduction of protobionts, bacteria and archea (prokaryotes) (3.5bya) , photosynthetic organism and oxygenation event (1.7-2.2 bya) and eukaryotes (2.1- 1.5 bya), Protista and fungi (1.0 bya) and animals (.75 bya)
When do the first fossils start appearing?
Precambrian- late Proterozoic
What are the two major events of the Paleozoic era?
Cambrian explosion- 542 mya
Permian extinction- 299 mya
What causes extinction?
Localized distribution Over specialization Interactions with other organisms Habitat change / destruction Natural events
What are the three most important mass extinctions?
Permian extinction- 255 mya
Triassic extinction- 205 mya
Cretaceous extinction- 65 mya
What era is the rise of the mammals?
The Cenozoic era
What groups evolved in the Cenozoic era?
Mammals
Flowering plants
Grasses
Birds
What is photorespiration?
When RuBp uses oxygen instead of CO2
What is mycelium?
The body of the fungi, made up of Hypha- small filaments
What are the 3 different cell wall structures in fungi?
Septate- all cells have cell walls
Septate (n+n) - cells have a cell wall with two nuclei in each
Aseptate- no cell walls
In fungi, which phase of life undergoes mitosis?
Haploid
In fungi, which phase of life undergoes meiosis?
The diploid
What are saprotrophs and what type of organism is one?
Organisms that obtain their nutrients from the dead, fungi are saprotrophs
What are the four types of fungi?
Zygomycetes
Glomeromycetes
Ascomycetes
Basidiomycetes
What are the characteristics of zygotmytotic fungi
Distinctive reproductive “zygospore” that ford around zygote
Examples- rhizopus–> bread mold
- pilobolus–> cow dung fungus
What are the characteristics of glomeromytotic fungi?
Form a obligate endo-mychorrhizal association with plant roots to help the plant absorb nutrients
What are the characteristics of ascomytotic fungi?
Reproductive cups called ascocarps made up of asci that produce spores…. Have a short stage of dikayrotic just before reproduction
What are the subgroups of ascomytotic fungi?
Conidiophores- molds like penicillium, aspergillus
Yeasts- Brewers and bread Yeast
What makes basidiomycetes unique?
Their reproductive structures are extremely large and come in 3 forms
- agaric
- stinkhorns
- shelf fungus
What kind of group is algae?
Polyphyletic- euglenoids, diatoms, grown and golden algae, archeplastids (red and green)
What events were primary endosymbiotic?
The addition of mitochondria and choroplasts
What kind of event was a secondary endosymbiosis?
A whole eukaryote takes in a eukaryotic algae
What are phaeophyta? What are their characteristics?
Brown algae- largest and most complex, multicellular, enveloped a red algae cell
What are coccolithophores?
Golden algae- unicellular with two flagella,protected by calcium carbonate
What are dinoflagellates?
Unicellular with two flagella, walls made of cellulose, causes red tides
What is the male producing part of a plant?
Antheridium
What is the female producing part of the plant?
Archegonium
What is the dominant stage of a bryophyte?
Gametophyte
What are tracheophytes?
Seedless vascular plants….club mosses, ferns
What are microphylls?
Outgrowths of stem tissue that developes into a singular vascular strand
What is the dominate stage of a tracheophyte?
Sporophyte
What is a gymnosperm?
Naked seed- seeded plant no flowers or fruits
What are male gametophytes called?
Microspores
What are female gametophytes called?
Megasporangium
