Brainscape's Knowledge GenomeTM

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


See full index

Biology 102 > Lecture 3 - Speciation II, History of Life on Earth, Intro to Animal Diversity, Invertebrates I > Flashcards

Lecture 3 - Speciation II, History of Life on Earth, Intro to Animal Diversity, Invertebrates I Flashcards

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

How old is earth?

A

4.5 billion years

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

How long has life existed on earth?

How long has human civilization been around?

A

~ 3.8 billion years

.0003% of history of life

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

How is the history of life conceptualized/organized?

A

Eras - Separated by catastrophic extinction boundaries

Periods - Subdivide eras

Differences in fossils in successive layers of rock

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

Pre-Cambrian

A
  • Super eon
  • origin of life
  • first 4 billion years of earths existence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Precambrian to cambrian transition

A
  • “explosion” of new life forms

- just over .5 billion years ago

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

Physical events that have contributed to nature and timing of evolutionary changes among organisms (5)

A
  • Continental drift
  • atmospheric oxygen concentrations
  • climate
  • volcanoes
  • extraterrestrial events (ex. meteorites)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Continental Drift

A
  • Earths crust consists of several plates 40km thick, floating on fluid layer of magma
  • Heat creates convection currents which exert pressure on plates
  • Move apart or together
  • Formation, size and position of continents
  • Oceanic circulation patterns, global climate, sea levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Himalayan Mountains

A

Ex: of continental drift

  • Tallest range in world
  • Created by Indian and Eurasian continental plates colliding
  • Collision caused plates to buckle and get pushed upwards
  • Himalayas continue to rise more than one cm a year
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Super-Continents

List them:

A
  • Caused by continental drift
  • Most recent super-continent was Pangaea
  • Believe that in 250 million years all continents will reform as one again
  • Ur
  • Kenorland
  • Columbia
  • Rodinia
  • Panhotia, Gondwana
  • Pangaea
  • Next super continent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Fossil Configuration and Continental drift

A
  • Fossil patterns in different continents show how they were connected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Continental Shift and Species Survival

What doe is affect? (3)

A
  • Shifting affects:
    1. oceanic circulation patterns
    2. global climates
    3. sea levels
  • Major drops in sea levels have usually been accompanied by massive extinctions, especially of marine organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Atmospheric Oxygen Concentrations

timeline

A
  • have changed over time
  • 2 major increases in oxygen
  • 1 major decrease

Timeline:

  • ~2 billion years ago: 1st photosynthetic bacteria
  • 750 mya - first increase
  • ~400 mya - second increase
  • 250 mya - decrease = great dying
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

First oxygen increase

What did it allow?

A
  • certain bacteria evolve ability to use water in photosynthesis. Oxygen released as a waste
  • Prokaryotes could evolve aerobic respiration
  • Advantages - aerobic metabolism proceeds more rapidly and harvests more energy than anaerobic
  • aerobes replaced most anaerobes
  • made possible: larger cells and more complex multicellular organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Second Oxygen Increase

What did it allow?

A
  • oxygen increased during carboniferous and permian periods
  • evolution of large vascular plants in lowland swamps
  • oxygen was 50% higher than today
  • allowed evolution of giant flying insects that wouldn’t survive in today’s atmosphere
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Drop in Oxygen

A
  • drying of swamps cause rapid drop in oxygen concentrations
  • “the great dying”
  • mass extinction of 96% of earth’s species

diversification of flowering plants helped gradually rebuild oxygen concentrations

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

Climate Change

A
  • Earth was often considerably warmer than today
  • Sometimes colder with extensive claciation
  • Range of average temps has spanned 10c or 18F
  • cold periods separated by long periods of milder climates
  • Short period of major climatic shifts: 5 - 10k years
  • Rapid climate changes typically lead to extinctions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Volcanoes

A
  • Many volcanic eruptions when the continents came together to form Pangaea in Permian period
  • occurred as continents drifted apart during the late Triassic and end of Cretaceous periods
  • Large volcanic eruptions inject ash ans sulfur dioxide into atmosphere –> leads to Sulphurous acid that blocks sunlight
  • Causes drop in temperature glaciations
  • potentially responsible for several mass-extinctions
  • Likely contributed to drying of swamps and killing of plants that caused “great dying”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Extraterrestrial Events

A
  • Collision with large meteorites cause of mass extinctions

Ex:

  • End of mesozoic period - end of dinosaurs
  • 180km crater located in mexico
  • = 100 million megatons of high explosives
  • plume of debrisheated atmosphere, ignited fires, blocked sunlight
  • settling debris formed iridium rich layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Date of Lower sea levels and glaciation mass ext.

A

444 million yrs ago

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

Date of “great dying”

A

251 million yrs ago

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

Date of Yucatan meteorite

A

65.5 million yrs ago

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

When was the first life?

When were the first eukaryotes?

A

Precambrian Era

  • first evolved about 3.5 - 3.8 billion years ago
  • mostly microscopic prokaryotes
  • Eukaryotes evolved part way through
  • 1.5-2.1 billion years ago
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

2 Major Events that set the stage for rapid diversification of Life that occurs upon entry into Cambrian period

A
  1. Evolution of Eukaryotes

2. Increasing oxygen levels

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

Cambrian Explosion

A
  • Begining of Paleozoic Era (542-488 mya)

- Oxygen levels approaching current level

25
Q

Rapid Diversification of Live in Cambrian Explosion

A
  • # individuals and species increased dramatically in the late Precambrian into the Cambrian
  • Many of the major groups of animal species seen today first evolved during the Cambrian
  • Largely or completely aquatic during this time
  • Foundation for most major Phyla of organisms was created
  • then tweaking, radiating, evolving groups of life
26
Q

Diversity of Species in Remainder of Paleozoic

A
  • more complex aquatic species developed
  • colonization of land, early amphibians and insects
  • mass extinction killed 96% of species
27
Q

Radiation of Reptiles and Mammals in Mesozoic and Cenozoic

A

Mesozoic:

  • Age of reptiles, including dinosaurs
  • first mammals appear (small)
  • mass extinction kills most species over ~50lbs

Cenozoic:

  • Extensive radiation of terrestrial vertebrates and flowering plants
  • Especially mammals
28
Q

Three domains of life

A

Archaea, Prokarya and Eukarya

Archaea more closely related to eukarya
have a common ancestor, after the common ancestor with prokarytes

29
Q

Characteristics of Animals

A
  1. Multicellularity
    - complex patterns of dev
    - no cell walls
  2. Heterotrophic Metabolism
    - must take in nutrients from their environment
  3. Internal Digestion
    - most habe internal gut which digestion breaks down molecules from environment into the organic molecules the animal needs
  4. Movement and Nervous System
    - most can move
    - coordinated through nervous system
    - muscle tissue
30
Q

Ancestor of Animals

A
  • colonial flagellated protist related to choanoflagellates
  • colony = individual members of a species living closely together toward mutual benefit, but can survive if separated on their own
  • certain cells began to become specialized
  • evolve into multicellular organisms with specialized cells
31
Q

Major derived traits

“umbrella pattern”

A
  1. Eumetazoa vs Sponges
    • Tissue vs no tissue
  2. Diploblastic vs Triploblastic
    • Tissue
    • 2 embryonic cell layers vs 3
  3. Protostome vs Deuterostome
    • Tissue
    • 3 embryonic cell layers
    • Mouth forms first vs anus forms first

Acoleomate, pseudocoelomate and coelomate
- protostomes and deuerostomes

32
Q

Eumetazoa vs Sponges

A
  • First Derived Trait - Distinct tissues
  • Tissues: Collection of specialized cells isolated from other tissues by a membrane (epithelial, muscle, etc)
  • Sponges have NO distinct tissue types, just specialized loosely arranged cells
  • ALL other animal groups are Eumetazoans, “True Animals”
  • Obvious body symmetry, gut, nervous system, tissue organized into distinct organs
  • Must have at least 2 embryonic cells layers (endoderm and ectoderm) to give rise to tissues
33
Q

Diploblastic vs Triploblastic

A

Radial vs Bilateral Symmetry

Diploblastic Animals

  • 2 embryonic cell layers (ectoderm outside, endoderm inside)
  • Radially Symmetrical
  • Body parts around one main axis (ex: comb jellies, corals, jellyfish, sea anenome)
  • Sedentary, shift with currents or move very slowly

Triploblastic Animals (Bilaterians)

  • 3 embryonic cell layers (ectoderm, medoderm in middle, endoderm)
  • Bilateraly symmetrical
  • cannot be divided into mirror image have by single plane through midline
  • distinct front end and planes: anterior/posterior; dorsal/ventral; left/right
  • correlated with cephalization (conc. of nervous tissue in head)
  • Exception: Echinoderms/starfish (adults are radial, larvae are bilateral_
34
Q

Protostome vs Deuterostome

A
  • Blastomere development in mouth and anus
  • 2 major triploblastic clades

Protostomes

  • blastopore becomes mouth
  • anus arises later

Deuterostomes

  • Blastopore becoems anus
  • mouth forms later
35
Q

Examples of Protostomes

A
  • arrow worms
  • Lophotrochozoans (flatworms, annelids, mollusks)
  • Ecdysozoans (nematodes, arthropods)
36
Q

Examples of Deuterostomes

A
  • Echinoderms (starfish, sea urchins)
  • hemichordates (acorn worms)
  • Chordates (vertebrates)
37
Q

Coelom

A
  • fluid filled body cavity
  • endoderm forms the gut
  • ectoderm froms outer layer, skin
  • mesoderm in middle surrounds cavity

Roles:

  • cushion internal organs
  • provides hydrostatic skeleton to support the organism and allow it to bend and move
  • allow organs to expand
38
Q

Ways Coelm can be organized

A
  • Acoelomate
  • Pseudocoelomate
  • Coelomate
39
Q

Acoelomate

A
  • lack an enclosed fluid-filled body cavity
  • mesoderm forms solid mass in contact with both endoderm and ectoderm
  • animals move by cilia
40
Q

Pseudocoelomate

A
  • animals have fluid-filled space in which many internal organs are suspended
  • Enclosed by mesoderm (muscle) only on the outside (in contact with ectoderm)
  • no inner layer of mesoderm surrounding internal organs (not in contact with endoderm)
41
Q

Coelomate

A
  • Animals have a body cavity that develops within the mesoderm
  • Coelom is enclosed on both inside and outside by mesoderm
  • all deuterostomes are coelomates
42
Q

Can protostomes be coelomates?

A

Yes, all three

43
Q

Major Groups of animals

A
  1. Sponges/Porifera
  2. Diploblasts
    (ctenophores, cnidarians)
  3. Triploblasts/Bilaterians
    (protostomes, deuterostomes)
44
Q

Sponges

A
  • simplest animals
  • no distinct embryonic cell layers, no true organs
  • lack body symmetry
  • considered plants until 1765
  • aggregation of cells built around water canal system

Feeding: filter feeding with intracellular digestion

  • water and food particles enter through pores and pass into open center cavity
  • flagella move the water in central cavity
  • specialized cells facing inside of this avity take up the food
  • no true tissues, no gut, no nervous system or circulatory
45
Q

Diploblasts

characteristics and examples of animals

A
  • Radial symmetry, endoderm/ectoderm

Ctenophores (comb jellies)
Cnidarians (jelyfish, sea anemone, corals)

46
Q

Cnidarians

A

Jellyfish, sea anenome, corals
- radial symmetry, diploblast

  • mouth connected to gastrovascular cavity
  • only one opening (mouth and anus), NO complete gut
  • cavity functions in digestion, circulation, gas exchange, hydrostatic skeleton
  • specialized musle-like fibers (from ectoderm) whose contractions allow movement
  • simple nerve nets to integrate body activities
  • specialized carnivores (toxins in tentacles ot capture large prey)
  • polyp and medusa life stage
47
Q

Eumetazoans

A

“True tissue”

Everything but sponges

48
Q

Ctenophores

A

COMB JELLIES

  • radial symmetry, diploblast
  • two cell layers separated by mesoglea
  • “jelly”
  • Complete gut
  • food enters through mouth and waste eliminated through anal pores
  • gas exchange but not a true circulatory system
  • Nerve net
  • move via beating comb-like rows of fused cilia
  • feed on small plankton
  • tentacles have adhesive materials that stick to prey
49
Q

Triploblasts

A

Bilaterians

Protostomes - blastopore becomes mouth first
Deuterostomes - blastopore becomes anus first

50
Q

Cnidarian Life cycle

movement, position of mouth, reproduction

A
  1. Polyp Stage
    - Sessile (don’t move)
    - Mouth faces up
    - Produce medusa by asexual budding
  2. Medusa Stage
    - free-swimming
    - floats with mouth and tentacles facing down
    - reproduce sexually
51
Q

Corals

A

Cnidarians
- diploblasts, radial symmetry, complete gut

  • polyps secrete a matrix of organic molecules on which they deposit calcium carbonate, which forms a skeleton
  • living polyps form a layer on top of a growing mass of skeletal remains. forms coral reefs and islands
  • grow in nutrient poor tropical waters (light is clear so light shines through)
  • photosynthetic dinoflagellates live endosymbiotically in their cells
  • warming leads to loss of endosymbionts/coral bleaching
  • conditions favor algae growth over coral growth
52
Q

Timeline of Mass Extinctions and causes

A
  • 444 mya - Lower sea levels and glaciation
  • 251 mya - The “Great dying, Oxygen levels
  • 65.5 mya - Yucatan meteorite (Extraterrestrial event –> climate, oxygen, etc)
53
Q

Ctenophores vs Cnidarians

A

Ctenophores (comb jellies)
- Complete gut

Cnidarians (jellyfish, corals, anemones)
- incomplete gut

BOTH:

  • diploblasts
  • radial symmetry
54
Q

What makes prokarya and archaea similar?

A
  1. DNA is not found in a nucleus and is usually circular
  2. no membrane bound organelles including nucleus
  3. divide by binary fission instead of mitosis
55
Q

Major Eras and Periods of Earth

A
  1. Precambrian
  2. Paleozoic
    • Cambrian
    • Ordovician
    • Silurian
    • Devonian
    • Carboniferous
    • Permian
  3. Mesozoic
    • Triassic
    • Jurassic
    • Cretaceous
  4. Cenozoic
    • Quaternary
    • Tertiary

“PPMC - please pass my cup”

56
Q

Paleozoic - Main Ideas

A

3 mass extinction

  • Development of SEA creatures
  • MASS EXT: sea levels dropped by 50 m
  • vascular plants
  • MASS EXT: 75% of marine species extinct- 2 meteorites
  • animals appear on land, giant insects
  • MASS EXT: 96% of species on earth - oxygen levels, “Great Dying”
57
Q

Mesozoic - Main Ideas

A
  • conifers develop
  • frogs
  • dinosaurs
  • flowering plants
  • radiation of plants and animals on land and sea
  • MASS EXT: most dinosaurs - meteorite
58
Q

Cenozoic - Main Ideas

A

Tertiaty

  • flowering plants dominate
  • grasslands spread, climate cools

Quaternary

  • 4 ice ages
  • homo sapiens

Biology 102 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions