Biology 104 - Exam 2 Flashcards
(112 cards)
1
Q
Hadean eon
A
- surface temp. 500-1000 ℃
- volcanic eruptions, earthquakes, intense UV radiation
- bombardment by comets, meteorites, possible asteroids
- atmosphere: pressure & chemical composition very different
2
Q
Extraterrestrial
A
- molecules of life arrived via meteorite
3
Q
Supernatural
A
- not within realm of scientific inquiry
4
Q
Miller & Urey
A
- 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
Q
stromatolites
A
sediment and cynobacteria
- some oldest fossils resemble stromatolites
6
Q
Prokaryotes
A
- 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
Q
nucleiod
A
where DNA resides
8
Q
plasmids
A
circles of DNA apart from the chromosome
9
Q
ribosomes
A
use mRNA to make proteins
10
Q
cell wall
A
gives cell shape
- bacteria have peptidoglycan –> archaea do not
11
Q
slime layer
A
sticky layer of proteins/polysaccharides that may surround cell wall
12
Q
pili
A
protein allow adhering
13
Q
flagella
A
whiplike extension that acts a propeller, allows cell to move
14
Q
endospore
A
- dormant inner cell protected by thick coat
- can survive boiling, drying, disinfectants. UV radiation
- have to be superheated to kill
15
Q
living organisms require ___, ___, ___
A
energy, carbon, liquid medium (body cells in water)
16
Q
Classifying prokaryotes
A
inorganic = photo(light)autotroph/chemo(carbon)autotroph organic = photoheterotroph/chemoheterotroph
17
Q
Bacteria
A
- 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
Q
symbiosis
A
close association between organisms of two species that live together for mutual benefit
19
Q
examples of bacteria
A
- actinomycete: soil bacteria => decomposition
- cyanobacteria: autotrophic, first to produce O2 via photosynthesis
- giant bacteria: visible to naked eye
20
Q
archaea
A
- originally characterized as extremophiles
- also found in less extreme environments
- essential to geochemical cycles on land/ in water
21
Q
examples of archaea
A
halophiles: slaty/saline environment
methanogens: methane gas produced as byproduct of anaerobic respiration
thermophiles: live in extremely hot environments
22
Q
pathogenic
A
disease causing bacteria
23
Q
nitrogen fixers
A
convert nitrogen from the atmosphere to available form of nitrogen (ammonia)
24
Q
prokaryotic function
A
- 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
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photosynthesis
light energy converted to chemical energy
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light reactions
- convert solar energy to chemical energy
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carbon reactions
uses chemical energy to make glucose from carbon dioxide
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chloroplast
- light absorbing organelle
- most dense interior cells of plant leaves
- green color comes from chlorophyll
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chlorophyll
```
a = dark green
b = light green
caratenoids = yellow
```
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protons
particles of light absorbed by chlorophyll --> when electron excited, gives off energy when dropping to original state
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water-splitting photosystem
replenishes electrons that get kicked out of chlorophyll
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electron-carrying photosystem
NADPH carries electrons to carbon cycle
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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
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eukaryotic cell
- nucleus
| - other membrane-bound organelles --> i.e. mitochondria
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evolution of endomembrane system
- hypothesized to be the infolding pf cell membrane
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evolution of mitochondrion & chloroplasts
- endosymbiont theory
| - mitochondria hypothesized to be aerobic bacteria --> chloroplast usually photosynthetic bacteria
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endosymbiont theory
mitochondrion and chloroplasts originated as free-living prokaryotes
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evidence - eukaryote evolution
- size, shape, structure similar between organelles and present bacteria
- analysis of DNA revealed similarities of bacterial DNA
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multicellularity
- 1.2 BYA resulted in explosion of variety of forms/sizes
| - evolved independently in several lineages ---> might also be due to symbiosis
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protist
eukaryote that is not plant, animal, or fungi --> many unicellular, many microscopic
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algae
- any photosynthetic protist that lives in water
- unicellular/multicellular
- chloroplasts with pigment variety
- functionality: produce atmosphere O2
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dinoflagellates
- cellulose with protective plates
| - red tide --> population explosion, produce toxin
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diatoms
- silica cell wall
| - two cell walls fit together like shoe box
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red algae
- many large, some microscopic
| - occupy deeper water => shorter light wavelengths needed to survive
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brown algae
- most complex and largest protists
| - food/habitat for other life
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green algae
- share many characteristics to plants
- unicellular, filamentous, colonial, multicellular
- ex. chlamydomonas, volvox, ulva
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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
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ciliates
- unicellular, some parasitic/symbiotic
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apicomplexans
- immobile, spore-forming internal parasites of animals
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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
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hyphae
cytoplasm strands, interconnected, secrete enzymes
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mycelium
mat that maximizes contact with organic matter
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fungi - reproduction
- release spores produced sexually/asexually
- spores germinate into hyphae where there is moisture and food
- classified by structure
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fungi - decomposers
- hyphae invasive, digest polymers
- air loaded with spores, colonize/initiate decomposition
- keep ecosystems stocked with inorganic nutrients for plant growth
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mycorrhizae
fungi + plant root exchange nutrients --> nitrogen + phosphate (fungi) for sugar (plant)
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lichens
fungi + algae, provide shelter in exchange for nutrients
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fungi - parasites
- 30% fungi parasitic
- attack agricultural crops/plants
- cause human disease
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plant
multicellular, photoautotrophic eukaryote
- evolved from aquatic ancestor
- use CO2, H2O, and light to form basis of life
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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
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charophyceans
closest living plant relatives
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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
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resources - plants
- light/CO2 aboveground
- water and minerals below ground
- avoid dehydration --> cuticle
- allow CO2 in --> stomata
- distant organs require support --> vascular tissue
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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
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cuticle
waxy covering to keep plant from drying out
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gametangium
protective jacket of cells surrounding moist chamber where egg is held
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bryophytes
- individuals grow in spongy habitats
- not aquatic => require wet habitats to acquire nutrients from reproduction
- liverworts, hornwort, mosses
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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
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angiosperms
- seed enclosed in ovary (fruit) --> facilitates dispersal
| - flower facilitates sexual reproduction --> draw attention of animals
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monocots
- one cotyledon
- usually parallel veins
- scattered vascular bundles
- floral parts in multiples of 3
- fibrous root system
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eudicots
- two cotyledon
- branched veins
- vascular ring bundles
- multiples of 4/5
- taprous root system
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angiosperm - reproduction
- 4 megaspores created, 1 survives
| - 1 egg but polar nuclei
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pollinaiton
pollen lands on stigma of flower --> pollen grain germinates into pollen tube
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double fertilization
- fertilizes both egg and polar nuclei
| - endosperm nucleus (3n) => triploid cell ---> provides resources to growing embryo
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animals
- eukaryotic, heterotrophic, obtains nutrients by ingestion and internal digestion
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invertabrates
without a backbone
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vertabrates
with a backbone
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bilateral symmetry
if only one plane can divide an animal into mirror image
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radial symmetry
if a plane through the body from mouth to opposite end creates multiple mirror images
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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
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2 germ layers
endoderm (in), ectoderm (out)
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3 germ layers
endoderm (in), mesoderm (mid), ectoderm (out)
86
protostomes
mouth develops first
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deuterostomes
anus develops first, mouth follows
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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
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pseudoderm
- partly lined with mesoderm
| - serves as hydrostatic skeleton
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incomplete digestive tract
food is ingested and excreted from the same opening
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complete digestive tract
mouth takes food in, anus expels waste
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segmentation
- division of body into different parts
| - flexibility & specialization of body
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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
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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
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polychaete
- crawl/burrow in sea floor, use hard bristles for movement
| - segments used for respiration
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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
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arthropods
- most abundant/diverse in animal kingdom
- phylum: arthropoda
- segmented animals with jointed appendages, exoskeleton, molting --> segments have specialized functions
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exoskeleton
- made of chitin & proteins --> flexible but tough
- protection and points for muscle attachment
must be shed for growth --> molting
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5 subphylla of arthropods
- trilobites (extinct)
- chelicerates - horseshoe crabs, spiders, scorpians, mites, ticks
- crustaceans
- millipedes/centipedes (myriapoda)
- insects
