Chapter 26-The Tree of Life Flashcards
The Earth formed as a hot mass of molten rock about ___ BYA.
4.5
Hypothesis that life arose spontaneously from chemically-rich early waters and life may have infected Earth from some other planet.
Panspermia
Contains gases that act as reducing agents
reducing atmosphere; gases include CO2, N2, H2O, and H2
Who experimented and reproduced the early reducing atmosphere?
Miller and Urey
___ may have been the first genetic material.
RNA
building blocks of amino acids
proteins
What innovations contributed to diversity od life?
- Eukaryotic cells
- sexual reproduction
- multicellularity
________ divided living things into plants and animals.
Aristotle
Linnaeus instituted the use of…
two-part names
binomials
two-part names
The science of classifying living things.
Taxonomy
A level of classification is called a _____.
Taxon
Levels of the Linnaean Hierarchy from most shared to least shared.
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
“tree of life” generated by cladistics
cladograms
__________ proposed a six-kingdom system.
Carl Woese
Transfer of genes by means other than traditional reproduction.
Horizontal Gene Transfer (HGT)
most abundant organism on Earth
bacteria
species
a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding
“nature’s recyclers”
bacteria; extract nitrogen from the air and recycle carbon and sulfur
prokaryotes that are more closely related to eukaryotes
archaea
characteristics of archaea
- cell walls lack peptidoglycan
- membrane lipids are branched
- distinct rRNA sequences
- divided into 3 main groups
3 main groups of archaea
methanogens, extremophiles, nonextreme archaea
methanogens
use H2 to reduce COs and CH4
extremophiles
- thermophiles=high temps
- halophiles=high salt
- acidophiles=low pH
