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
nonextreme archaea
grow in the same environment as bacteria
Eukaryotes appeared about ____ BYA.
2.5
___________ have an extensive endomembrane system that divides the cell into functional compartments.
Eukaryotes
Mitochondria and chloropasts most likely gained entry by _________, or one cell engulfing another.
endosymbiosis
Mitochondria derived from:
purple nonsulfur bacteria
Chloroplasts derived from:
cyanobacteria
4 eukaryotic kingdoms
protista, fungi, plantae, animalia
protista
-unicellular with few multicellular organisms
largely multicellular organisms, each is a distinct evolutionary line derived from a unicellular protist
fungi, plantae, and animalia
key eukaryotic characteristics
compartmentalization, multicellularity, sexual reproduction
compartmentalization
allows for increased sub cellular specialization
multicellularity
allows for differentiation of cells into tissues
sexual reproduction
allows for greater genetic diversity
