Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Origin and the History of Life > Flashcards

Origin and the History of Life Flashcards

1
Q

organism

A

Any living entity that contains one or more cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the general five characteristics of life?

A
  • Energy
  • Cells
  • Information
  • Replication
  • Evolution
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

theory

A

A proposed explanation for a broad class of phenomena or observations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cell

A

A highly organized compartment bounded by a thin, flexible structure (plasma membrane) and containing concentrated chemicals in an aqueous (watery) solution. The basic structural and functional unit of all organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

cell theory

A

The theory that all organisms are made of cells and that all cells come from preexisting cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the two general components of scientific theory?

A
  • describes a pattern in the natural world

- mechanism or process that is responsible for that pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Evolution

A

(1) The theory that all organisms on Earth are related by common ancestry and that they have changed over time, predominantly via natural selection. (2) Any change in the genetic characteristics of a population over time, especially, a change in allele frequencies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Natural Selection

A

The process by which individuals with certain heritable traits tend to produce more surviving offspring than do individuals without those traits, often leading to a change in the genetic makeup of the population. A major mechanism of evolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

heritable

A

Referring to traits that can be transmitted from one generation to the next.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

population

A

A group of individuals of the same species living in the same geographic area at the same time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

artificial selection

A

Deliberate manipulation by humans, as in animal and plant breeding, of the genetic composition of a population by allowing only individuals with desirable traits to reproduce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

fitness

A

An organisms ability to survive and replicate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

adaptation

A

Any heritable trait that increases the fitness of an individual with that trait, compared with individuals without that trait, in a particular environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the two central and unifying ideas of biology?

A
  • The cell is the fundamental structural unit in all organisms
  • All species are related by common ancestry and have changed over time in response to natural selection.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

speciation

A

The evolution of two or more distinct species from a single ancestral species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

phlogeny

A

The evolutionary history of a group of organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the characteristics of a phylogenic tree?

A

-Like a family tree shows relationships between individuals, a phylogenic tree shows relationships between species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

taxonomy

A

Any named group of organisms at any level of a classification system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

taxon

A

Any named group of organisms at any level of a classification system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

domain

A

(1) A section of a protein that has a distinctive tertiary structure and function. (2) A taxonomic category, based on similarities in basic cellular biochemistry, above the kingdom level. The three recognized domains are Bacteria, Archaea, and Eukarya.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

phylum

A

In Linnaeus’ system, a taxonomic category above the class level and below the kingdom level. In plants, sometimes called a division.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

genus

A

In Linnaeus’ system, a taxonomic category of closely related species. Always italicized and capitalized to indicate that it is a recognized scientific genus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

scientific name

A

Name that includes both genus and species name in latin form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

fossil

A

Any trace of an organism that existed in the past. Includes tracks, burrows, fossilized bones, casts, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
fossil record
All of the fossils that have been found anywhere on Earth and that have been formally described in the scientific literature.
26
How are fossils generally formed?
When part or all of an organism is buried under ash, sand, mud or some other type of sediment.
27
Is fossilization common?
No
28
What are the limitations of Fossil Record?
Habitat bias(most likely organisms that lived in areas where sediments are actively being deposited) - Taxonomic and Tissue bias(organisms with more hard parts more likely to survive) - Temporal bias(recent fossils more common than ancient) - Abundance bias(species that survived on earth for greater times leave more evidence)
29
What was the initial way fossils were categorized into time periods? Modern way?
Rock formations or fossilized organisms to identify the boundaries for time intervals. Now radiometric dating used for absolute dates.
30
Precambrian era
The interval between the formation of the Earth, about 4.6 billion years ago, and the appearance of most animal groups about 543 million years ago. Unicellular organisms were dominant for most of this era, and oxygen was virtually absent for the first 2 billion years.
31
Paleozoic era
The period of geologic time, from 543 million to 250 million years ago, during which fungi, land plants, and animals first appeared and diversified. Began with the Cambrian explosion and ended with the extinction of many invertebrates and vertebrates.
32
Mesozoic era
The period of geologic time, from 250 million to 65 million years ago, during which gymnosperms were the dominant plants and dinosaurs the dominant vertebrates. Ended with extinction of the dinosaurs. Also called Age of Reptiles.
33
Cenozoic era
The most recent period of geologic time, beginning 65 million years ago. during which mammals became the dominant vertebrates and angiosperms became the dominant plants. Also called Age of Mammals.
34
prebiotic soup
A hypothetical solution of sugars, amino acids, nitrogenous bases, and other building blocks of larger molecules that may have formed in shallow waters or deep-ocean vents of ancient Earth and given rise to larger biological molecules.
35
adaptive radiation
Rapid evolutionary diversification within one lineage, producing numerous descendant species with a wide range of adaptive forms.
36
What are the three halmarks of adaptive radiation?
1) monophyletic group 2) fast speciation 3) diversified ecologically
37
niche
The particular set of habitat requirements of a certain species and the role that species plays in its ecosystem.
38
What two mechanisms trigger adaptive radiations?
- new resources | - new ways to exploit new resources
39
Ecological Oppurtunity
The availability of new or novel types of resources
40
Why is the evolution of morphological traits so important?
Allowed descendents to live in new areas, exploit new sources of food or move in new ways, triggered many of the important diversification events in the history of life
41
Cambrian explosion
The rapid diversification of animal body types that began about 543 million years ago and continued for approximately 40 million years.
42
fauna
All the animals characteristic of a particular region, period, or environment.
43
What are the three major fossil assemblages of the cambrian explosion?
- doushantuo microfossils(tiny sponges) - edicarian faunas(sponges, jellyfish,..) - Burgess Shale faunas(most complicated organisms)
44
What triggered the Cambrian explosion?
- higher oxygen levels - the evolution of predation - new niches beget more new niches - new genes, new bodies
45
mass extinction
The extinction of a large number of diverse evolutionary groups during a relatively short period of geologic time (about 1 million years). May occur due to sudden and extraordinary environmental changes.
46
background extinction
The average rate of low-level extinction that has occurred continuously throughout much of evolutionary history.
47
What are the differences between mass and background extinctions?
no set rule or differences, scientists study 5 mass extinctions. However, background extinction is generally regarded as a function of natural selection and mass extinctions a genetic drift.
48
What caused the end-Permian extinction?
Unknown, one of the most important unsolved questions in the history of life.
49
Impact hypothesis
Asteroid struck the earth and killed 60-80 percent of multicellular organisms around 65 million years ago.
50
Where did the oxygen in earth's atmoshpere come from?
Cyanobacteria
51
cyanobacteria
A lineage of photosynthetic bacteria formerly known as blue-green algae. Likely the first life-forms to carry out oxygenic photosynthesis.
52
Why was the evolution of aerobic respiration such a crucial event in the history of life?
Because oxygen is extremely electronegative, it is an efficient electron acceptor, more efficient than other substances.
53
nitrogen fixation
The incorporation of atmospheric nitrogen (N2) into forms such as ammonia (NH3) or nitrate (NO3–), which can be used to make many organic compounds. Occurs in only a few lineages of bacteria and archaea
54
LUCA
Last Universal Common Ancestor
55
What's the average lifespan of an average species?
1-10 million years
56
Evolutionary Radiations
Periods of major diversification
57
Who are the Fathers of Geology?
James Hulton | Charles Lyell
58
Index Fossils
Fossils used to indicate time period of rock formation
59
What are the different eras from oldest to youngest?
Precambrian, Paleozoic, mesozoic, cenozoic
60
holotype
Physical example of a species
61
Unstable radioisotopes are used for measuring what?
Useful for dating igneous rocks
62
What is the key for measurement of radioisotopes?
Half-lives
63
Where does the energy for continent movement originate?
Core of Earth
64
How were the mega-continents of the past discovered and mapped?
Fossil records
65
Formula for decay of radioisotope
N = N0 e^-lambda t lambda = decay constant , N = # atoms present
66
half-life
time required for half the atoms initially present to decay. | Formula:T(half life) = 0.693/ lambda
67
Type specimen
Ideal of species
68
Error rate DNA
1 nucleotide per million
69
How many base pairs in humans?
3.2 billion
70
Alfred Wallace
Scientist who came up with similar ideas to Darwin at same time period. Postulated the occurrence of adaptation in response to natural selection

Biology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions