Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIO 80 > Chapter 25 & 27 > Flashcards

Chapter 25 & 27 Flashcards

(51 cards)

Start Studying
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

Study These Flashcards
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

Study These Flashcards
A

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

23
Q

What’s special about Prokaryotes

Study These Flashcards
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

Study These Flashcards
A

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

25
Hypotonic
Net movement of water into the cell, more solute inside
26
Isotionic
Osmotic equilibrium, no net movement, solute concentrations are equal inside and outside
27
most prokaryotes _____ water and ____ in _____ environments
Lose, burst, hypertonic
28
peptidoglycan
a network of sugar polymers cross-linked by polypeptides
29
Archaeal walls contain ________ and proteins, and lack __________
polysaccharides, peptidoglycan
30
Gram-positive
Simple walls, with large amounts of peptidoglycan
31
Gram-negative
Complex walls with outer membrane, contains lipopolysaccharides and less peptidoglycan
32
Why are gram-negative bacteria more resistant to bacteria
Antibiotics target peptidoglycan, which gram-negative bacteria contain very little of in their membrane
33
Capsule V.S. Slime layer
Capsule bacteria are dense and well-defined, Slime-layer bacteria are not well organized
34
Endospores
Copies of bacterial chromosome surrounded by a multilayered structure produced when water/nutrients are lacking in bacteria
35
Fimbriae
hairlike appendages that allow prokaryotes to stick to their substrate or other bacteria
36
Pili
Longer (than Fimbriae) appendages that pull bacteria together and allow the exchange of DNA
37
Flagella
Tail-like structure used for movement
38
Plasmids
Rings of independently replicating DNA in prokaryotes
39
What are some key features of Prokaryote reproduction
1. They are small 2. Reproduce by binary fission 3. Short generation times
40
Binary Fission
asexual reproduction where identical (except mutations) cells are produced
41
Transformation
When prokaryotic cells incorporate foreign DNA from surroundings
42
Transduction
When phages (bacteria infecting viruses) carry genes from one host to another
43
Conjugation
The process of two prokaryotic cells transferring DNA through a Sex Pili
44
R Plasmids
Plasmids that carry antibiotic resistance genes.
45
Phototrophs
Cells that obtain energy from light
46
Chemotrophs
Cells that obtain energy from chemicals
47
Autotrophs
Require CO2 as fuel source
48
Heterotrophs
Require organic nutrients (often created by autotrophs) to make the organic compounds
49
Obligate aerobes vs Obligate anaerobes vs Facultative anaerobes
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
Nitrogen fixation
Prokaryotes that convert N2 to ammonia (NH3)
51
Heterocyst
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