Biology 104 - Exam 2 Flashcards Preview

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Flashcards in Biology 104 - Exam 2 Deck (112):
1

Hadean eon

- surface temp. 500-1000 ℃
- volcanic eruptions, earthquakes, intense UV radiation
- bombardment by comets, meteorites, possible asteroids
- atmosphere: pressure & chemical composition very different

2

Extraterrestrial

- molecules of life arrived via meteorite

3

Supernatural

- not within realm of scientific inquiry

4

Miller & Urey

- replicated/simulated Earth's atmosphere and conditioned and added energy
- condensation of liquid containing amino acids
- hypothesized: minerals of dry/hot surfaces (earth) catalyzed reactions

5

stromatolites

sediment and cynobacteria
- some oldest fossils resemble stromatolites

6

Prokaryotes

- 2 billion years --> lived/evolved alone
- found wherever life is found --> outnumber eukaryotes
- can cause disease, be beneficial, important for nutrient cycling, important to organisms
- bacteria and archaea
- reproduce by binary fission

7

nucleiod

where DNA resides

8

plasmids

circles of DNA apart from the chromosome

9

ribosomes

use mRNA to make proteins

10

cell wall

gives cell shape
- bacteria have peptidoglycan --> archaea do not

11

slime layer

sticky layer of proteins/polysaccharides that may surround cell wall

12

pili

protein allow adhering

13

flagella

whiplike extension that acts a propeller, allows cell to move

14

endospore

- dormant inner cell protected by thick coat
- can survive boiling, drying, disinfectants. UV radiation
- have to be superheated to kill

15

living organisms require ___, ___, ___

energy, carbon, liquid medium (body cells in water)

16

Classifying prokaryotes

inorganic = photo(light)autotroph/chemo(carbon)autotroph
organic = photoheterotroph/chemoheterotroph

17

Bacteria

- majority of known prokaryotes
- form symbiosis with other organisms
- may cause disease
- many produce antibiotics
- found in food, food webs, break down organic matter

18

symbiosis

close association between organisms of two species that live together for mutual benefit

19

examples of bacteria

- actinomycete: soil bacteria => decomposition
- cyanobacteria: autotrophic, first to produce O2 via photosynthesis
- giant bacteria: visible to naked eye

20

archaea

- originally characterized as extremophiles
- also found in less extreme environments
- essential to geochemical cycles on land/ in water

21

examples of archaea

halophiles: slaty/saline environment
methanogens: methane gas produced as byproduct of anaerobic respiration
thermophiles: live in extremely hot environments

22

pathogenic

disease causing bacteria

23

nitrogen fixers

convert nitrogen from the atmosphere to available form of nitrogen (ammonia)

24

prokaryotic function

- many do work in human body
- good bacteria crowd out bad --> some essential to digestion
- harmful bacteria can be ingested/inhaled/enter body through wounds or orfices
- ecologically important --> essential decomposers

25

photosynthesis

light energy converted to chemical energy

26

light reactions

- convert solar energy to chemical energy

27

carbon reactions

uses chemical energy to make glucose from carbon dioxide

28

chloroplast

- light absorbing organelle
- most dense interior cells of plant leaves
- green color comes from chlorophyll

29

chlorophyll

a = dark green
b = light green
caratenoids = yellow

30

protons

particles of light absorbed by chlorophyll --> when electron excited, gives off energy when dropping to original state

31

water-splitting photosystem

replenishes electrons that get kicked out of chlorophyll

32

electron-carrying photosystem

NADPH carries electrons to carbon cycle

33

carbon cycle

input: 9 ATP, 6 NADPH, 3 CO2
output: 9 ADP + 9 P, 6 NADP+, 1 G3P
- need for glucose --> power cell respiration
---> cellulose/starch are basis to build organism

34

eukaryotic cell

- nucleus
- other membrane-bound organelles --> i.e. mitochondria

35

evolution of endomembrane system

- hypothesized to be the infolding pf cell membrane

36

evolution of mitochondrion & chloroplasts

- endosymbiont theory
- mitochondria hypothesized to be aerobic bacteria --> chloroplast usually photosynthetic bacteria

37

endosymbiont theory

mitochondrion and chloroplasts originated as free-living prokaryotes

38

evidence - eukaryote evolution

- size, shape, structure similar between organelles and present bacteria
- analysis of DNA revealed similarities of bacterial DNA

39

multicellularity

- 1.2 BYA resulted in explosion of variety of forms/sizes
- evolved independently in several lineages ---> might also be due to symbiosis

40

protist

eukaryote that is not plant, animal, or fungi --> many unicellular, many microscopic

41

algae

- any photosynthetic protist that lives in water
- unicellular/multicellular
- chloroplasts with pigment variety
- functionality: produce atmosphere O2

42

dinoflagellates

- cellulose with protective plates
- red tide --> population explosion, produce toxin

43

diatoms

- silica cell wall
- two cell walls fit together like shoe box

44

red algae

- many large, some microscopic
- occupy deeper water => shorter light wavelengths needed to survive

45

brown algae

- most complex and largest protists
- food/habitat for other life

46

green algae

- share many characteristics to plants
- unicellular, filamentous, colonial, multicellular
- ex. chlamydomonas, volvox, ulva

47

water molds

- decomposers/parasites of plants & animals

48

slime molds

- live in damp habitats
- single cells OR large masses acting like multicellular
- plasmodial --> bacteria/dead organic matter as food

49

protozoa

- "first animal"
- most unicellular/chemoheterotophs
- ingest/absorb energy & carbon
- aquatic --> free-living, some parasitic
- mostly asexual reproduction

50

ciliates

- unicellular, some parasitic/symbiotic

51

apicomplexans

- immobile, spore-forming internal parasites of animals

52

fungi

- eukaryotes
- most multicellular heterotrophs
- more related to animals than plants
---> store excess glucose as glycogen, cll wall made of chitin
- live everywhere
- essential decomposers

53

hyphae

cytoplasm strands, interconnected, secrete enzymes

54

mycelium

mat that maximizes contact with organic matter

55

fungi - reproduction

- release spores produced sexually/asexually
- spores germinate into hyphae where there is moisture and food
- classified by structure

56

fungi - decomposers

- hyphae invasive, digest polymers
- air loaded with spores, colonize/initiate decomposition
- keep ecosystems stocked with inorganic nutrients for plant growth

57

mycorrhizae

fungi + plant root exchange nutrients --> nitrogen + phosphate (fungi) for sugar (plant)

58

lichens

fungi + algae, provide shelter in exchange for nutrients

59

fungi - parasites

- 30% fungi parasitic
- attack agricultural crops/plants
- cause human disease

60

plant

multicellular, photoautotrophic eukaryote
- evolved from aquatic ancestor
- use CO2, H2O, and light to form basis of life

61

origin - plants

- closely related to green algae
- ancestor thought to have lived in water habitat with periods of dryness --> natural selection favored those who could survive both
- terrestrial adaptation used today are basis for defining major groups

62

charophyceans

closest living plant relatives

63

land adaptation

1. must acquire resources in different way
2. new habitat requires support and material transport
3. adaptations for reproduction in new drier environment

64

resources - plants

- light/CO2 aboveground
- water and minerals below ground
- avoid dehydration --> cuticle
- allow CO2 in --> stomata
- distant organs require support --> vascular tissue

65

alternation of generations

- gametophyte + sporophyte => each produces the other but in different ways
- gametes (n) => fertilization => zygote (2n) => mitosis => sporophyte (2n) => meiosis => spores (n) => mitosis => gametophyte (n) => mitosis => gametes (n)
- multicellular diploid sporophyte makes haploid cells by meiosis
- multicellular haploid gametophyte makes haploid gametes by mitosis

66

cuticle

waxy covering to keep plant from drying out

67

gametangium

protective jacket of cells surrounding moist chamber where egg is held

68

bryophytes

- individuals grow in spongy habitats
- not aquatic => require wet habitats to acquire nutrients from reproduction
- liverworts, hornwort, mosses

69

seedless vascular plants

- true roots & stems with lignin and leaves
- resources collected from different places, still need water to reproduce
- xylem (water) and phloem (sugar) tubes
- ferns

70

gymnosperms

- cone-bearing plants with exposed seeds
- appeared at end of carboniferous period > colder and dryer
- complete life cycle on dry land, withstand harsh cold
- pollen sacs produce microspores, female cones produce megaspores

71

angiosperms

- seed enclosed in ovary (fruit) --> facilitates dispersal
- flower facilitates sexual reproduction --> draw attention of animals

72

monocots

- one cotyledon
- usually parallel veins
- scattered vascular bundles
- floral parts in multiples of 3
- fibrous root system

73

eudicots

- two cotyledon
- branched veins
- vascular ring bundles
- multiples of 4/5
- taprous root system

74

angiosperm - reproduction

- 4 megaspores created, 1 survives
- 1 egg but polar nuclei

75

pollinaiton

pollen lands on stigma of flower --> pollen grain germinates into pollen tube

76

double fertilization

- fertilizes both egg and polar nuclei
- endosperm nucleus (3n) => triploid cell ---> provides resources to growing embryo

77

animals

- eukaryotic, heterotrophic, obtains nutrients by ingestion and internal digestion

78

invertabrates

without a backbone

79

vertabrates

with a backbone

80

bilateral symmetry

if only one plane can divide an animal into mirror image

81

radial symmetry

if a plane through the body from mouth to opposite end creates multiple mirror images

82

cephalization

concentrated sensory organs and a brain in the organisms head
- seen with bilateral symmetry

83

germ layer

in animals with true tissues, groups of cells that interact and contribute to the formation of tissues and organs

84

2 germ layers

endoderm (in), ectoderm (out)

85

3 germ layers

endoderm (in), mesoderm (mid), ectoderm (out)

86

protostomes

mouth develops first

87

deuterostomes

anus develops first, mouth follows

88

coelom

body cavity
- tube within tube body design
- fluid filled --> cushions organs, permit growth and movement, separate from outer body wall
- forms completely within mesoderm

89

pseudoderm

- partly lined with mesoderm
- serves as hydrostatic skeleton

90

incomplete digestive tract

food is ingested and excreted from the same opening

91

complete digestive tract

mouth takes food in, anus expels waste

92

segmentation

- division of body into different parts
- flexibility & specialization of body

93

sponges

- multicellular, lacks true tissues
- phylum: porifera
- spicules: spines to repel predators
- filter feeders: cells specialized to move water, trap/digest food, distribute nutrients
- collar cells: cells lining inner sponge membrane with flagella

94

cnidarians

- multicellular, two layers of true tissues, radially symmetric, incomplete digestion, no segmentation, body wall is hydrostatic skeleton, specialized cells
- phylum: cnidaria
- reproduce sexually/asexually
- cnidocytes: stinging cells
- polyp form --> sessile, medusa form --> free-living
- carnivores
- gastrovascular cavity --> cells secrete enzymes for digestion

95

flatworms

- bilateral symmetry, protostomes, incomplete digestion, organ system, simple cephalization
- phylum: platyhelminthes
- simple bilateral symmetry --> no coelom
- some free-living/some parasitic
- flat body allows exchange of materials with environment

96

planarians

- free-living flatworms
- hermaphroditic
- secrete mucus for protection

97

parasitic

- tapeworms --> live in host (suckers and hooks)
- blood flukes --> intermediate host (snails)

98

Mollusks

- organ system, bilateral symmetry, usual cephalization/simple brain, hydrostatic skeleton, sexual reproduction, complete digestive tract, soft bodied, unsegmented, most protected by hard shell, no segmentation

99

gastropoda

single, spiral shaped shell --> snail

100

bivalves

shell of two halves --> scallop, clam

101

cephalopoda

shell, no shell, reduced shell --> octopus, squid

102

mantle

layer of specialized tissue, covers visceral mass

103

radula

raspy mouthpart used to scrape/tear up food

104

foot

movement (gastropods, cephalopods), attachment/digging

105

annelids

- organ system, bilateral, cephalization, true coelom, complete digestion, repeating segments
- phylum: annelida
- terrestrial, freshwater, marine
- oligochaete --> hermaphroditic (earthworms/leeches)
- polychaete --> separate sexes

106

clitellum

site of fertilization

107

oligochaete

- earthworms/leeches
- leeches --> strong jaws, saliva contains anesthetic and anticoagulant

108

polychaete

- crawl/burrow in sea floor, use hard bristles for movement
- segments used for respiration

109

roundworms

- organ system, bilateral, cephalization, pseudocoelom, complete digestion, no segmentation, molting (cuticle)
- phylum: nematoda
- aquatic, wet terrestrial habitats
- free-living --> decomposers
- parasitic --> live in fluids/tissues of host

110

arthropods

- most abundant/diverse in animal kingdom
- phylum: arthropoda
- segmented animals with jointed appendages, exoskeleton, molting --> segments have specialized functions

111

exoskeleton

- made of chitin & proteins --> flexible but tough
- protection and points for muscle attachment
must be shed for growth --> molting

112

5 subphylla of arthropods

- trilobites (extinct)
- chelicerates - horseshoe crabs, spiders, scorpians, mites, ticks
- crustaceans
- millipedes/centipedes (myriapoda)
- insects