Chapters 15-17 Flashcards
(98 cards)
1
Q
when did earth form
A
about 4.6 billion years ago
2
Q
how first life may have evolved
A
- abiotic synthesis of small organic molecules, such as amino acids and nitrogenous bases
- joining of these small molecules into polymers, such as proteins and nucleic acids
- packaging of these molecules into “protocells”
- origin of self-replicating molecules that eventually made inheritance possible
3
Q
what does O2 tend to do?
A
As a strong oxidizing agent, O2 tends to disrupt chemical bonds.
4
Q
next 3 stages of life
A
- Abiotic synthesis of polymers
- Formation of protocells
- Self-replicating RNA
5
Q
macroevolution
A
evolutionary change above the species level. encompasses…
- the origin of a new group of organisms through a series of speciation events and
- the impact of mass extinctions on the diversity of life and its subsequent recovery.
6
Q
radiometric dating
A
- is based on the decay of radioactive isotopes (unstable forms of an element)
- can date rocks and fossils.
- carbon-14 decays to another element
7
Q
plate tectonics
A
the theory that Earth’s crust is divided into giant, irregularly shaped plates that essentially float on the underlying mantle.
8
Q
permian extinction
A
linked to the effects of extreme volcanic activity.
9
Q
cretaceous extinction
A
included most dinosaurs. may have been caused by the impact of an asteroid.
10
Q
adaptive radiations
A
periods of evolutionary change in which many new species evolve from a common ancestor.
11
Q
“evo-devo”
A
combines evolutionary and developmental biology.
12
Q
taxonomy
A
branch of biology concerned with identifying, naming, and classifying species.
13
Q
binomial
A
two-part scientific name
14
Q
phylogeny
A
The evolutionary history of a species or group of species
15
Q
systematics
A
a discipline of biology that focuses on
- classifying organisms
- determining their evolutionary relationships.
16
Q
phylogenetic tree
A
a hypothesis of evolutionary relationships.
17
Q
analogy
A
Similarity due to convergent evolution
18
Q
cladistics
A
groups organisms by common ancestry.
19
Q
clade
A
monophyletic group that consists of an ancestral species and all its evolutionary descendants—a distinct branch in the tree of life.
20
Q
Cladistics two main types of characters
A
- A shared ancestral character
2. A shared derived character
21
Q
shared ancestral character
A
common to members of a particular clade, but originated in an ancestor that is not a member of the clade.
22
Q
shared derived character
A
common to members of a particular clade and is not found in its ancestors.
23
Q
parsimony
A
the adoption of the simplest explanation for observed phenomena.
24
Q
molecular systematics
A
uses DNA or other molecules to infer relatedness.
25
molecular clock
a method that estimates the time required for a given amount of evolutionary change.
26
Earliest form of life
prokaryotes about 3.5 to 2 billion years ago
27
origin of single-celled eukaryotes
1.8 billion years ago. originated when prokaryotic cells became capable of aerobic respiration or photosynthesis
28
origin multicellular eukaryotes
1.2 billion years ago. larger organisms 600 million years ago.
29
earth's eon history
hadean, archaean, Proterozoic, and Phanerozoic
30
paedomorphosis
the retention in the adult body of structures that were juvenile features in an ancestral species
31
hierarchical classification of an animal
species -> genus -> family => orders => classes => phyla => kingdoms => domains
32
taxon
each taxonomic unit at any level
33
convergent evolution
occurs when similar environments and natural selection produce similar adaptations in organisms from different evolutionary lineages
34
outgroup
a species from a lineage that is closely related to but not part of the group of species we are studying
35
horizontal gene transfer
a process in which genes are transferred from one genome to another through mechanisms such as plasmid exchange and viral infection.
36
metagenomics
researchers collect samples from a particular environment, and isolate and sequence the DNA they contain
37
microbiome
genomes of individual species
38
microbiota
the community of microorganisms that live in and on our bodies
39
pathogens
disease-causing agents
40
cocci
spherical prokaryotic cells.
41
streptococci
cocci that occur in chains
42
bacilli
rod-shaped prokaryotes
43
3 most common prokaryote cell shapes
1. cocci
2. bacilli
3. spiral shape
a. Relatively short and rigid cells called spirilla and
b. Longer and more flexible cells called spirochetes.
44
purpose of a cell wall
- provides physical protection
| - prevents the cell from bursting in a hypotonic environment
45
Gram-positive bacteria
have simpler walls with a relatively thick layer of peptidoglycan
46
peptidoglycan
a polymer of sugars cross-linked by short polypeptides
47
gram-negative bacteria
less peptidoglycan and are more complex, with an outer membrane that contains lipids bonded to carbohydrates.
-often more toxic and more threatening
48
fimbriae
hairlike projections that enable some prokaryotes to stick to a surface or to one another.
49
endospore
a specialized resistant cell
50
prokaryotic phototrophs
capture energy from sunlight
51
chemotrophs
prokaryotes that harness the energy stored in chemicals, either organic or inorganic chemicals
52
autotrophic
when organisms make their own organic compounds
53
autotrophs
prokaryotes that obtain their carbon atoms from carbon dioxide
54
photoautotrophs
prokaryotes that harness sunlight for energy and use C0(2) for carbon
55
photoheterotrophs
prokaryotes that obtain energy from sunlight but get their carbon atoms from organic sources
56
chemoautotrophs
prokaryotes that harvest energy from inorganic chemicals and use carbon from C0(2) to make organic molecules.
57
chemoheterotrophs
prokaryotes that acquire both energy and carbon from organic molecules
58
biofilms
highly organized colonies of prokaryotes
59
bioremediation
use of organisms to remove pollutants from the soil, air, or water.
60
extreme halophiles
archaea that thrive in very salty places
61
extreme thermophiles
archaea that thrive in very hot water
62
methanogens
archaea that live in anaerobic environments and give of methane as a waste product.
63
proteobacteria
bacteria all gram-negative and share a particular rRNA sequence.
64
symbiosis
a close association between organisms of two or more species
65
cyanobacteria
the only group of prokaryotes with plantlike, oxygen-generating photosynthesis.
66
chlamydias
live inside eukaryotic host cells.
67
five groups bacteria
-proteobacteria
-gram-positive bacteria
cyanobacteria
-chlamydias
-spirochetes
68
spirochetes
helical bacteria that spiral through their environment by means of rotating, internal filaments. include notorious pathogens
69
exotoxins
proteins that bacterial cells secrete into their environment
70
endotoxins
lipid components of the outer membrane of gram-negative bacteria that are released when the cell dies or is digested by a defensive cell.
71
protists
diverse collection of mostly unicellular eukaryotes
72
SAR
largest and most diverse supergroup of eukaryotes. Protist clades Stramenopila, Alveolata, and Rhizaria.
73
diatoms
unicellular algae that are one of the most important photosynthetic organisms on Earth
74
charophytes
photosynthetic eukaryotes. plants and green algae
75
how do plants maintain moisture?
C0(2) and O(2) diffuse across leaf surfaces through stomata (tiny pores)
76
apical meristems
growth-producing regions of cell division
77
vascular tissue
a network of thick-walled cells joined into narrow tubes that extend throughout the plant body.
78
two types of vascular tissue
xylem and phloem
79
xylem
include dead cells that form microscopic pipes conveying water and minerals up from the roots
80
phloem
consists entirely of living cells. distributes sugars throughout the plants
81
lignin
thickens and reinforces the cell walls of some plant tissues
82
gametangia
gametes in male and female structures
83
pollen grains
structures that contain the sperm-producing cells
84
seed
consists of an embryo packaged with a food supply within a protective covering
85
alternation of generations
the diploid and haploid stages are distinct, multicellular bodies
86
gametophyte
haploid generation of a plant produces gametes
87
sporophyte
diploid generation produces spores
88
pollination
when a pollen grain lands on a compatible female structure, it undergoes mitosis to produce a sperm
89
fruit
ripened ovary of a flower
90
hyphae
feeding structures of a fungus that are a network of threadlike filaments
91
mycorrhiza
symbiosis between fungi and plant roots
92
mold
any rapidly growing fungus that reproduces asexually by producing spores
93
yeast
any single-celled fungus
94
lichens
symbiotic associations of millions of microscopic green algae or cyanobacteria held in a mass of fungal hyphae
95
what opportunities did life on land offer adaptations?
- bright and abundant sunlight,
- abundant atmospheric CO2,
- initially, few pathogens or plant-eating animals.
96
disadvantages that life on land had
- maintain moisture inside their cells,
- support the body in a nonbuoyant medium,
- reproduce and disperse offspring without water,
- anchor their bodies in soil
- obtain resources from soil and air.
97
Three key events occurred in the history of the plant kingdom.
1. Origin of land plants
2. Origin of vascular plants
3. Origin of seed plants
98
bryophytes
include mosses, hornworts, and liverworts
