ch 40, 39, + ecology Flashcards
(190 cards)
1
Q
4 main stages of food processing
A
- ingestion
- digestion
- absorption
- elimination
2
Q
can animals use macromolecs in their polymer state?
A
no; must be broken down into monomers first
3
Q
digestion
A
the process of breaking down food into molecs small enough to be absorbed
4
Q
monomers
A
fuel for ATP prod or for biosynth
5
Q
what does mechanical fragmentation do?
A
incs SA for digestive enzymes
6
Q
food vacoules
A
organelles in which hydrolytic enzymes break down food (intracellular digestion)
7
Q
what is one advantage of having extracellular digestion?
A
much larger food than by phagocytosis
8
Q
what groups do not have complete digestive tracts (2)?
A
cnidaria, platy’s
9
Q
complete digestive tract (3)
A
- mouth
- digestive tube
- anus
10
Q
crop/stomach
A
storage & preliminary digestion
11
Q
gizzard
A
grinding
12
Q
intestine
A
absorption of nutrients into blood
13
Q
what does a complete digestive tract enable?
A
ingestion of additional food before earlier meals are completely digested
14
Q
peristalsis
A
rhythmic waves of contraction by smooth muscles in gut wall push food along
15
Q
sphincters
A
muscular ring-like valves that regulate passage of material btwn specialized chambers
16
Q
4 accessory glands
A
- gall bladder
- liver
- pancreas
- salivary glands
17
Q
what does saliva lubricate food with?
A
a glycoprotein (mucin) + salivary amylase
18
Q
what does salivary amylase do?
A
hydrolyzes starch and glycogen into smaller polysaccharides
19
Q
tongue
A
tastes, manipulates, shapes food into a bolus
20
Q
pharynx opens to both
A
- esophagus
- trachea
21
Q
epiglottis
A
a cartilaginous flap that blocks the glottis when swallowing
22
Q
rugae
A
accordion-like folds in the stomach that stretch to accommodate food
23
Q
what does the stomach secrete and for what?
A
gastric juices to churn
24
Q
what is the pH of the gastric juices in your stomach
A
2
25
what do the gastric juices do (2)?
- denatures pros
| - kills most bacteria that are swallowed
26
pepsin
begins hydrolysis of pro's by breaking peptide bonds
27
why is pepsin secreted in an inactive form, pepsinogen?
HCl activates it; don't want it all the time
28
how many days does it take the epithelial cells in our stomach lining to be completely replaced by mitosis?
3 days
29
mixing and enzyme action converts food into nutrient rich..?
acid chyme
30
acid reflux/heartburn
occasional backflow into lower esophagus
31
pyloric sphincter
regulates the opening to the small intestine
32
how long, on avg, does it take for the stomach to empty?
2 hrs
33
small intestine (2)
- digests
| - absorbs nutrients into blood
34
how long is the small intestine in humans?
6m
35
what does the small intestine perform?
enzymatic hydrolysis
36
duodenum
first 25cm of the small intestine
37
acid chime mixes with digestive juices from (4)
- pancreas
- lives
- gall bladder
- intestinal epithelium
38
pancreas prods (2)
- hydrolytic enzymes
| - alkaline solution rich in bicarbonate, which red. the acidity
39
what produces bile?
the liver
40
where is bile stores until it is needed
gall bladder
41
bile salts in liver aid in the digestion of?
fats
42
what do pancreatic amylases do?
hydrolyze polysaccs into disaccs
43
what does maltase do?
splits maltose into 2 glucose molecs
44
sucrase splits sucrose into
glucose and fructose
45
what two molecs secreted in inactive form by the pancreas attack specific peptide bonds?
trypsin and chymotrypsin
46
how are fats dealt with (2)?
1. bile salts coat droplets and keep them emulsified
| 2. lipase hydrolyses fat molecs into glycerol and fatty acids
47
where does most digestion occur?
duodenum
48
what two structures absorb nutrients with their huge SA?
jejunum and ileum
49
villi
fingerlike protections for absorption found on the intestinal lining with many microvilli on it
50
SA via (4) structures
- length
- plicae
- villi
- microvilli
51
what two cell layers separate lumen of intestine from the bloodstream?
intestinal epithelium and epithelium of capillaries
52
hepatic portal vessel (2)
where intestinal veins converge; leads to liver
53
regardless of carb content of meal, blood has glucose [] close to ?
0.1%
54
large intestine major function
reclaiming w
55
how long is the human colon?
1.5m
56
how much of the 7L of w secreted into the digestive tract every day is reabsorbed?
over 90%
57
colons have a rich flora of bacteria which (2)
- are mostly harmless
| - prod vitamins
58
what is one of the major reasons mammals have been so successful?
teeth; specialized dentition
59
who has longer intestinal tract:body size ratio?
herbivores and omni
60
what is harder to digest, meat or plants?
plants; cellulose
61
how do we break down cellulose?
w/ symbiotic bacteria in special fermentation chambers that have enzymes that can digest cellulose and simple sugars
62
homeostasis
steady state physiological condition of body
63
-ive feedback
a change in the variable being monitored triggers a response that counteracts initial fluctuation
64
what is the primary mechanism of homeostasis?
-ive feedback
65
when blood glucose levels rise above a certain point (2)
1. pancreas secretes insulin into blood
| 2. insulin stimulates liver and muscle cells to make glycogen, dropping blood glucose lvls
66
when blood glucose levels drop below a certain point (2)
1. pancreas secretes glycagon into blood
| 2. glycagon promotes breakdown of glycogen and release of glucose into blood
67
what is the endocrine function of the pancreas?
signals cells to regulate lvls in the blood
68
what is the exocrine function of the pancreas?
secretes digestive enzymes in ducts
69
+ive feedback
a change in some variable triggers mechanisms that amplify change
70
what is one example of +ive feedback that relates to cc?
albedo affect
71
who has an open circulatory system?
arthropods and mollusks
72
hemolymph
no distinction btwn blood and interstitial fluid
73
closed circ system
blood confined to vessels
74
closed circ system of vertebrates
cardiovascular system
75
atria
chambers that receive returning blood
76
ventricles
chambers that pump blood out
77
what happens to blood pres when blood flows through a capillary bed?
drops substantially
78
how many chambers does a fish heart have?
2
79
how many chambers do amphibians and reptiles hearts have?
3
80
one disadvantage of amphibian hearts
mixing of O2 poor and rich blood
81
what is one advantage to a 4 chambered heart?
restores pres and prevents blood mixing
82
what is one essential adaptation for endotherms?
a 4 chambered heart
83
how much more E do endotherms use over endotherms?
10x more
84
4 chambered hearts in birds and mammals is an example of
convergent evolution
85
ecology
the study of interactions btwn orgs and their env
86
env includes
biotic and abiotic factors
87
pop
a species
88
community
pops that interact w/ each other in a specific area
89
ecosystem/biome
community + abiotic factors
90
organismal ecology studies ?
how orgs meet the challenges of their envs, through morphology, physiology, and behaviour
91
pop ecology studies?
interactions w/in species; pop growth, size, structure
92
community ecology studies?
interspecies interactions; parasitism, disease, predation, competition
93
ecosystem ecology studies?
how E and nutrients flow through a ecosystem
94
how to nutrients flow?
recycled
95
E in a system
passed upwards but some is lost in every transformation
96
what determined where a species is or isn't found (4)
1. ability to disperse
2. behaviour
3. biotic factors (predators, parasites, competitors, etc.)
4. abiotic factors (geology, sunlight, climate)
97
3 ways of sampling the density of a pop
- sample plots (quadrats)
- indirect indicators (nests, droppings, etc.)
- mark & recapture
98
3 ways of describing pops
- density
- dispersion
- demography
99
3 types of dispersion
- clumping
- uniform
- random
100
why would orgs clump (2)?
- food, nesting sites, etc
| - social behaviours, mating
101
why would orgs be uniformly dispersed?
antagonistic interactions; territoriality, plant allelochemicals, etc
102
why would orgs be randomly dispersed?
no interactions (rare)
103
demography
the study of vital statistics that affect pop size
104
what are some vital statistics that affect pop size (2)?
- birth and immigration rates
| - death and emigration rates
105
life tables
summarize the vital stats of a pop
106
what do life tables do (2)?
- follow a cohort from birth to death
| - measure mortality, survivorship, births, etc through diff age classes
107
survivorship curves
plot a portion of cohort still alive vs age
108
type 1
small # of well-cared for offspring; many survive to old age
109
type 2
consistent line
110
type 3
offspring w/ no parental care; many die young
111
natural selection favours strategies that?
max lifetime repro success
112
fitness
how many offspring you have that survive to adulthood compared to others in the pop
113
good fitness is affected by (3)?
- clutch size
- # of repros/lifetime
- age at 1st repro
114
clutch
offspring/event
115
how does clutch size relate to offspring size (2)?
- smaller clutch, bigger offspring
| - bigger clutch, smaller offspring
116
early breeding females are often smaller. what does this result in (3)?
- smaller clutch
- less E for later clutches
- lower lifetime repro success
117
exponential growth model
assumes max rate of growth (r max)
118
r max (3)
- max birth rate per female
- all kids survive
- repro forever & faster->
119
k
max # that env can support
120
logistic pop growth
pop limited by K (Carrying capacity) of the env
121
which model can life histories be related to?
logistic pop growth model
122
r-selected species (5)
- evolved to maximize r-max (inc quickly)
- favours opportunists
- many small offspring
- no parental care
- type 3 survivorship curves
123
k-selected species (5)
- evolved in pops that were near carrying capacity (high density)
- not opportunists
- few, big offspring
- parental care
- long life; delayed maturity
- type 1 survivorship curves
124
what regulates pop size?
a combination of density dependent and independent factors
125
density dependent pop regulation
effects inc as pop size incs; tends to keep the pop around k
126
3 eg of effects that inc as pop incs
- less resources per individual
- predation incs
- crowding changes behaviour/physiology
127
what does less resources/individual mean for a pop (2)?
- less food, territories, nest sites
| - lower survival, less offspring
128
what does crowding mean for a pop?
delayed maturity, fewer offspring
129
density independent factors
abiotic factors that decrease a pops size no matter how big/small; natural disaster, weather
130
fluctuations
- r-selected spp sometimes have big fluctuations
| - k has some
131
cycles (2)
- 10 or 12 yr turns
| - regular cycles may be due to time lags of density-dependent factors (predation, epidemics)
132
what model do human pops follow?
exponential
133
5 reasons humans follow the exponential model
- clean w
- sanitation
- medicine
- agri
- technology/mechanization
134
what are 4 ways medicine helps humans achieve the exponential growth model?
- stop of infectious disease
- antibiotics
- hygene
- immunization
135
rate of growth of human pop influenced by (2)
- what country you're in
| - age structure (lots of kids inc pop later)
136
how many kids/woman would keep the pop even?
2.1
137
carrying cap for humans?
10-15 bill
138
ecological footprint
land and w area needed by a nation/person to get all of its resources and dispose of its wastes
139
why does ecological footprint vary with country?
because resources are limited; not evenly distributed
140
what is the human pop doing to the carrying capacity for other spp?
dec
141
interspecific
existing or occurring between different species
142
intraspecific
produced, occurring, or existing within a species or between individuals of a single species
143
interspecific interactions include (7)
- competition
- predation
- herbivory
- mutualism
- disease
- commensalism
- parasitism
144
ecological niche
the sum of a species' use of the biotic and abiotic resources in its env; how and where it makes its living
145
competitive exclusion principle
no two species can occupy exactly the same niche
146
what happens if two species occupy the same niche (4)?
- the superior competitor may drive other spp to extinction
- competition may limit a sp to a more limited niche than it might otherwise occupy
- species w/ similar niches may come to subdivide the niche (resource partitioning)
- direct competition may push sympatric pops od species to become diff (character displacement)
147
predation drives
evolutionary "arms race"
148
predators evolved (4)
- speed
- good sensory systems
- camoflague
- mimicry
149
prey evolved (7)
- speed
- hiding behaviour
- cryptic colouration
- mechanical defenses
- group defenses
- group vigilance
- chem defenses
150
aposematic colouration
warning of defenses
151
Batesian mimicry
harmless sp resembles a dangerous one
152
Mullerian mimicry
several diff spp resemble each other
153
herbivory
plant/algae is partially consumed
154
plant adaptations (3)
- tough covering hairs
- gritiness
- 2ndary compounds (toxins, etc)
155
herbivore adaptations (2)
- ability to detect plant
| - ability to overcome host defenses (detoxify, store to use them itself, etc)
156
parasitism
parasites harm the host
157
ectoparasites
found on outside of host
158
endoparasites
feed inside host
159
eg. salt march community
parasitism may play an important role in forming community structure
160
disease is mostly due to microscopic pathogens (4)
viruses, bacteria, fungi, protists
161
what are 2 species that are susceptible hosts to diseases?
- chesnut
| - elm
162
mutualism
interactions that favour both spp
163
two egs of mutualism
- Acacia and speudomyrex ant
| - pollinators and angiosperms
164
commensalism
one species benefits, one neither gains nor loses
165
co-evolution
one sp has put a selective pressure on the other and vice versa
166
one eg of commensalism
cattle and birds
167
species diversity
the variety of diff kinds of orgs in a comm
168
community characteristics (4)
- species diversity
- feeding relationships
- the role of 1 or 2 key species
- responses to disturbance
169
2 components of species diversity
- species richness
| - relative abundance of each spp
170
why is it better to think in food webs rather than food chains?
many spp don't occupy just one trophic level
171
E transfer btwn trophic lvls is usually what % efficient?
under 20% (limits food chain length)
172
what lvl of a food chain is the most precarious?
top
173
dominant spp
most abundant/have greatest biomass
174
what do dominant spp do?
influence which other spp can survive there
175
keystone spp
need to be abundant but act to maintain diversity (not always dom)
176
2 egs of keystone species
- seastars: eat mussels and stop them from dom
| - sea otters: eat sea urchins that would otherwise destroy kelp forests
177
ecosystem engineers
cause physical changes that affect comm structure
178
3 egs of ecosystem engineers
- humans
- beavers
- termites
179
one eg of a comm that has evolved in the face of regular disturbances
lodgepole pine; fire
180
ecological succession
gradual predictable change in a comm structure after a disturbance
181
primary succession
begins from bare rock
182
secondary succession
begins from intact soil
183
eg of secondary succession
bare rock -> moss/fireweed -> shrubs -> alder forest -> spruce forest -> hemlock and spruce forest (climax)
184
why does succession occur (2)?
- each stage creates conditions that favour the next stage
| - inhibit members of current stage (alders killing their own kinds)
185
why is there greater diversity in tropical habitats (2)?
- more E
| - stability
186
island equil model (3)
- predicts that species # is related to 'island' size and distance to a 'mainland'
- more spp = lower rate of arrival of new spp b/c most of those spp are already on the island
- more extinctions of new arrivals b/c more competitive exclusion
187
island equil model predicts
more species on large islands near the mainland
188
individualistic hypothesis
the plant spp in a place simply have similar ecological reqs
189
integrated hypothesis
comm is an association of ecologically linked spp
190
eg of integrated hyp
hemlock and western red cedar
