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DAT Biology > Chapter 2 Origin and Diversity of Life > Flashcards

Chapter 2 Origin and Diversity of Life Flashcards

1
Q

What was the composition of early earth?

A
  • no free O2

- CO, CO2, N2, H2, S, HCl, HCN

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2
Q

How did oceans form?

A

cooling -> condensation of water vapour -> rain -> oceans

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3
Q

What does the Oparian- Haldane hypothesis suggest?

A
  • reducing environment of early earth
  • simple molecules became primordial soup of organic monomers
  • upon exposure to UV light, lightning, radioactivity, heat
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4
Q

Miller-Urey Experiment…

A

tested Oparian Haldane hypothesis by providing early earth conditions (H2, N2, CO, CO2, HCl, HCN) with electric current to simulate lightning
- synthesis of complex organic molecules from simple inorganic

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5
Q

“self-replicating genetic material like RNA was earliest life form that eventually became self-sustaining through metabolic networks” defines what?

A

RNA World (Naked Gene) Hypothesis

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6
Q

“isolated environments allowed formation of metabolic networks that eventually became earliest life form” defines what hypothesis?

A

Metabolism-First hypothesis

hypothesis for early forms of life

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7
Q

What are protobionts?

A

primitive cells that formed isolated environment for chemical reactions to occur

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8
Q

What are 2 types of protobionts?

A

coacervates (lipid spheres)

microspheres (polypeptide spheres)

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9
Q

What is the earliest autotroph and what is it known for?

A

cyanobacteria

  • O2 byproduct
  • formation of ozone layer
  • creation of oxygen rich environment today
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10
Q

What is the endosymbiotic theory?

A

engulfment of one prokaryote led to another mutually beneficial association to form the modern eukaryote
- mitochondria and chloroplast

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11
Q

What are bacterial cell walls made up of?

A

peptidoglycans - sugar polymer with amino acids

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12
Q

What are plant cell walls made up of?

A

cellulose

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13
Q

What are fungal cell walls composed of?

A

chitin - sugar

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14
Q

What is a difference between archaea and eubacteria in terms of DNA?

A
  • archaea is packed in histones

- bacteria is naked circular bacterial DNA

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15
Q

What are Archaea cell walls composed of?

A

polysaccharides

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16
Q

What is an endospore?

A

non-reproductive structure containing bacterium’s DNA (protect DNA)

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17
Q

What are filaments of fungi called? What do they form?

A

hyphae

mycelium

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18
Q

What is the role of septa in fungi?

A

divides it into compartments, each with a single nucleus

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19
Q

Are fungi autotrophs or heterotrophs?

A
  • heterotrophs
  • absorb the breakdown products from digestive enzymes that they secrete
  • therefore parasites or saprobes
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20
Q

What are haustoria?

A

hyphae (fungi filaments) that penetrate host

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21
Q

Do fungi reproduce sexually or asexually

A

both!

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22
Q

How do fungi reproduce sexually?

A
  • fungi are normally haploid,

- must be diploid to reproduce

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23
Q

What is plasmogamy?

A
  • two normal haploid fungi cells fuse to form single cell with 2 haploid nuclei = dikaryon
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24
Q

What is a dikaryon?

A

single cell with 2 haploid nuclei

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25
Q

What is karyogamy?

A

dikaryon forms single diploid nucleus (2 nuclei one cell to one nuclei one cell)

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26
Q

What is the final step to sexual reproduction of fungi?

A

meiosis of the newly formed diploid cell

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27
Q

Fungi asexual reproduction can occur via fragmentation, budding, and asexual spore production. How are spores formed?

A
  • sporangiospores are in sac like capsules = sproangia

- conidia are not in capsules

28
Q

Where are sporangia found?

A

sporangia at stalks of of sporangiophores

29
Q

Where are conidia found?

A

not in capsules at hyphae called conidiophores

30
Q

What is the eumatazoa and parazoa group?

A

eukaryotic anamalia tissue differences

  • eumatazoa tissue layers that develop into organs
  • parazoa group do not have tissue layers or organs
31
Q

Which phyla of kingdom anamalia are deuterosomes?

A

chordates and echinodermata (sea urchins and star fish - most similar phyla to chordata)

32
Q

This organism reproduces asexxually, has asymmetrical symmetry and is a parazoa. What phyla of anamalia is it?

A

Porifera

parazoa means no true tissues
they are immobile and are the earliest form of animals

33
Q

This organism has a two way digestive tract, but no coelom. What phyla does it belong to?

A

Platyhelminthes
(flatworms)
coelom is the main body cavity
excretory system has flame cells - filters harmful substances

34
Q

This organism has a one way digestive tract in the soil. What is this?

A

Nematoda
(roundworms)
- pseudocoelom

35
Q

This organism has one way digestive tract and gills for respiration. It has a mantle as well. What phyla?

A

Mollusca

  • one way digestion
  • coelom
  • gills - live in aquatic or land
  • mantle: thin layer of tissue that builds shells
36
Q

This phyla has one way digestion and a coelomate (true body cavity). They have segmented circular bodies.

A

Annelida

earthworms and leeches

37
Q

Arthropods have one or complete digestive system (start and end)?

A

one way

- exoskeleton

38
Q

Name example of echinodermata.

A

Starfish, sea urchins

39
Q

Do echinodermata have one way or complete digestive systems?

A

complete digestive system

= deuterosome

40
Q

What is the difference between some vertebrates such as birds and reptiles in comparison to humans (chordata) in terms of excreting waste?

A

birds and reptiles secrete uric acid

humans secrete urea

41
Q

Chordates are only vertebrates. True or false?

A

False.
Chordates can be separated into vertebrates and invertebrates.
*chordates means development of the notochord during embryonic development

42
Q

What does the dorsal hollow nerve cord become after embryonic development?

A

spinal cord and brain

43
Q

What does the notochord become after embryonic development of chordates?

A

vertebral column (bone) and muscles

44
Q

Embryonic chordates have gills. True or false.

A

True.

Pharyngeal gill slits becomes gills, pharynx or feeding mechanism

45
Q

Parenchyma, Collenchyma, Sclerenchyma are classes of ____

A

ground tissue of plant cells: these provide structural support

46
Q

What tissue is the site of photosynthesis in ground tissue of plants?

A

parenchyma

47
Q

What is the role of dermal tissue?

- 2 types

A

protection from dehydration

  • epidermal layer
  • guard cells (stomata = opening)
48
Q

Xylem transports __ and Phloem transports ___

A

xylem: water (up)
phloem: sugars (down)

49
Q

Xylem + Phloem = (term)

A

vascular bundles

50
Q

In the vascular bundles, some tissues are dead and some are living at maturity. Which is which?

A

phloem is living - but no nuclei or ribosomes

xylem is dead tissue - therefore no cellular components

51
Q

If there are no cellular components or nuclei in vascular bundles (depending on the type of tissue) how do they carry metabolic needs of the cell?

A
  • metabolism is conducted via parenchyma connection via plasmodesmata
52
Q

What is the casparian strip in roots?

A

band of fatty material between endodermis = suberin

- water impermeable barrier

53
Q

What are the parts of the stem?

A

epidermis
cortex
vascular cylinder (xylem, phloem, pith)

54
Q

Where is vascular cambium located and what is it?

A
  • undifferentiated cells that are between xylem and phloem
55
Q

What are the female parts of a flower (angiosperm)

A

pistil:
ovary (swollen part with gametophytes)
style (stalk)
stigma (top)

56
Q

What are the reproductive male parts of the flower?

A

anther (microspores)

filament (stalk)

57
Q

Prior to fertilization, the megaspore mother cell in the ovule goes through meiosis. What is the result of these divisions?

A
  • embryo sac with micropyle (opening)
  • egg cell
  • two synergid cells
  • 3 antipodal cells
  • 2 haploid polar nuclei
58
Q

What structures are fertilized of the female gametes?

A
  • haploid egg cell fertilized as pollen enteres micropyle
  • polar nuclei forms triploid nucleus to produce endosperm (nourishment)
    = double fertilization
59
Q

What is auxin?

A

plant hormone that promotes ELONGATION

60
Q

What is gibberelins?

A

plant hormone that promotes cell growth

61
Q

What is cytokinin?

A

plant hormone that stimulates cell division

62
Q

What is ethylene?

A

gas that promotes fruit ripening or flower production

63
Q

What is abscisic acid (ABA?

A

growth inhibitor that can maintain dormancy in seeds

64
Q

What is phototropism?

A
  • sunlight affecting the side that plant will gorw - auxin
65
Q

What did lobe-finned fish evolve from?

A

jawless fish -> cartilaginous fish -> lobe-finned fish

66
Q

What are the significant steps of evolution in order for chordates?

A
  • notochord (lancelets and tunicates)
  • head (hagfish)
  • vertebral column (jawless fish)
  • jaw and mineralized skeleton (sharks)
  • lungs (rayfinned fish)
  • lobed fins
  • limbs with digits (amphibians)
  • amniotic eggs (reptiles)
  • production of milk (mammals)
67
Q

Apoplastic vs Symplastic?

A

Water moves through cell walls = apoplastic

Symplastic = moves through one cell to the other via plasmodesmata - through the cytoplasm connected

DAT Biology (12 decks)

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