Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO 80 > Chapter 25 & 27 > Flashcards

Chapter 25 & 27 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the four steps hypothesized to have brought life about

A
  1. Abiotic synthesis of organic molecules
  2. Formation of organic polymers - repeating units
  3. Formation of Protocells: membrane-bound, cell precursors
  4. Formation of ribozymes: protein enzymes made of RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How was the early Earth atmosphere like

A
  • Organic molecules formed from simpler molecules
  • Energy for reactions from lightning/UV radiation
  • Oceans were full of organic molecules (primordial soup)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

______ processes could have produced the early building blocks of life

A

Abiotic

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

Why are bogs good fossil repositories

A
  • Low oxygen
  • Low water flow
  • Acidic soils
  • inhibit microbial and fungal activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are two methods to age fossils

A
  1. Carbon-dating
  2. Radiometric dating
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The geological record is divided into ______, _______, ______, and ______ _____

A

Hadean, Archaean, Proterozoic, Phanerozoic, Eons

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

Approximately how long did the first three Eons add up to

A

4 Billion years

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

How long have we been in the Phanerozoic Eon, and what has arisen since

A

600 Million years, Multicellular Eukaryotic Life

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

What three era’s is the Phanerozoic Eon divided into

A
  1. Paleozoic Era
  2. Mesozoic Era
  3. Cenozoic Era
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What occurred in the Archaean Eon

A

First prokaryotes arose 3.5 BYA, only life form from 3.5 BYA to 2.1 BYA

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

Oxygen Revolution

A

O2 producing photosynthesis became dominant, allowed organisms to gain energy from the sun and enabled cellular respiration

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

Wha occurred in theProterozoic Eon

A

Single-celled eukaryotes arose 1.8 BYA, evolved via endosymbiosis

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

What is endosymbiosis

A

When a prokaryotic cell engulfed another cell, and evolved the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What occured in the Proterozoic Eon

A

Multicellular Eukaryotes evolved 1.3 BYA, which gave way to algae, plants, animals, and fungi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What occured during the Paleozoic eon

A

Cambrian explosion, which is marked by the sudden appearance of fossils

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

Continental Drift

A

The slow movement of Earth’s continents as the underlying mantle moves.

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

What are some consequences of Continental Drift

A
  • Reduction in shallow water habitats
  • Colder and drier climate inland
  • Changes in climate w/ movement away from the poles
  • Changes in ocean circulation patterns (global cooling)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The break of Pangaea lead to ______ ______

A

Allopatric speciation

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

Permian Mass Extinction

A
  • Occurred 252 MYA
  • Separates Paleozoic & Mesozoic Era’s
  • Lasted 5 MY, wiped 95% of marine animals
  • Caused by Volcanism, leading to global warming, and decrease in oceanic oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Cretaceous Mass Extinction

A
  • Occurred 65.5 MYA
  • Separates Mesozoic & Cenozoic Era’s
  • Happened in 10k yrs
  • 75% of species (terrestrial plants & animals) went extinct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Adaptive Radiation

A

The evolution of diversely adapted species from a common ancestor upon introduction to new environmental opportunities (new niches, little competition)

22
Q

What are Prokaryotes

A

Single-celled organisms that make up the Bacteria & Archaea domains

23
Q

What’s special about Prokaryotes

A
  • Adapted to diverse/extreme environments
  • Most abundant organism on Earth
  • First organism to inhabit Earth
  • .5-5 um in length (vs 10-100um eukaryotes)
24
Q

Hypertonic

A

Net movement of water out of the cell, more solute outside

25
Q

Hypotonic

A

Net movement of water into the cell, more solute inside

26
Q

Isotionic

A

Osmotic equilibrium, no net movement, solute concentrations are equal inside and outside

27
Q

most prokaryotes _____ water and ____ in _____ environments

A

Lose, burst, hypertonic

28
Q

peptidoglycan

A

a network of sugar polymers cross-linked by polypeptides

29
Q

Archaeal walls contain ________ and proteins, and lack __________

A

polysaccharides, peptidoglycan

30
Q

Gram-positive

A

Simple walls, with large amounts of peptidoglycan

31
Q

Gram-negative

A

Complex walls with outer membrane, contains lipopolysaccharides and less peptidoglycan

32
Q

Why are gram-negative bacteria more resistant to bacteria

A

Antibiotics target peptidoglycan, which gram-negative bacteria contain very little of in their membrane

33
Q

Capsule V.S. Slime layer

A

Capsule bacteria are dense and well-defined, Slime-layer bacteria are not well organized

34
Q

Endospores

A

Copies of bacterial chromosome surrounded by a multilayered structure produced when water/nutrients are lacking in bacteria

35
Q

Fimbriae

A

hairlike appendages that allow prokaryotes to stick to their substrate or other bacteria

36
Q

Pili

A

Longer (than Fimbriae) appendages that pull bacteria together and allow the exchange of DNA

37
Q

Flagella

A

Tail-like structure used for movement

38
Q

Plasmids

A

Rings of independently replicating DNA in prokaryotes

39
Q

What are some key features of Prokaryote reproduction

A
  1. They are small
  2. Reproduce by binary fission
  3. Short generation times
40
Q

Binary Fission

A

asexual reproduction where identical (except mutations) cells are produced

41
Q

Transformation

A

When prokaryotic cells incorporate foreign DNA from surroundings

42
Q

Transduction

A

When phages (bacteria infecting viruses) carry genes from one host to another

43
Q

Conjugation

A

The process of two prokaryotic cells transferring DNA through a Sex Pili

44
Q

R Plasmids

A

Plasmids that carry antibiotic resistance genes.

45
Q

Phototrophs

A

Cells that obtain energy from light

46
Q

Chemotrophs

A

Cells that obtain energy from chemicals

47
Q

Autotrophs

A

Require CO2 as fuel source

48
Q

Heterotrophs

A

Require organic nutrients (often created by autotrophs) to make the organic compounds

49
Q

Obligate aerobes vs Obligate anaerobes vs Facultative anaerobes

A

Aerobes require O2 for cellular respiration, while Anaerobes are poisoned by O2; Facultative can use O2 if present, if not they use fermentation or anaerobic respiration

50
Q

Nitrogen fixation

A

Prokaryotes that convert N2 to ammonia (NH3)

51
Q

Heterocyst

A

Cells that prevent oxygen penetration in colonies

BIO 80 (12 decks)

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