final exam Flashcards
(184 cards)
1
Q
what type of cancer is processed meat linked to?
A
21% of bowel cancer
the meat forms N-nitroso compounds such as nitrosamines (which are potent
carcinogens) as they react during the processing, storage and/or cooking process
2
Q
Are naturally sourced nitrates better than synthetic ones with respect to the “chemistry” of processed meat?
A
no
3
Q
It is estimated that eating processed and red meats leads to a ____ % increase in bowel cancer.
A
21%
4
Q
What is innate immunity?
A
Is the immunity we are born with, it includes barriers (skin), phagocytic cells, antimicrobial proteins, the inflammatory response, and natural killer cells.
5
Q
What are the first barriers/lines of defense of the innate immune system?
A
skin and mucous membrane, temperature,
low pH and chemical mediators, inflammatory response
6
Q
Neutrophils, macrophages and natural killer cells are all types of _______ blood cells.
A
white
7
Q
What are interferons and how do they protect cells against viral attack?
A
infected cell produces infron proteins that exocytose from cell and enter another non infected cell and stimulates that cell to produce antiviral proteins to protect itself from infection
8
Q
What does a Mast cell produce?
A
histamine
9
Q
Describe the steps of an inflammatory response
A
mast cells signal WBC thats theres a problem
capillaries diolate (widen) and become leaky so neutrophils can exit and enter imfection
neutrophils digest bacteria and tissue repairs
10
Q
What are the three key ingredients of pus?
A
dead white blood cells,
fluid leaked from capillaries and tissue debris
11
Q
What can be found in lymph nodes?
A
Lymph nodes filter substances that travel through the lymphatic fluid, and they contain lymphocytes (white blood cells) that help the body fight infection and disease.
12
Q
whats the function of the lymphatic sys?
A
to fight infection and return fluids to circulatory sys
13
Q
What is the adaptive immune response? what are the 2 types?
A
activated only after exposure to pathogens
humoral response
cell mediated response
14
Q
whats the humoral response
A
antibodies defend against infection in body fluids
15
Q
whats the cell mediated response in adaptive imm?
A
the destruction of infected cells by cytotoxic T cells
16
Q
What is an antigen?
A
any molecule that provokes imm resppnse
17
Q
What is an antibody?
A
a protein dissolved in blood plasma that attaches to a specific kind of antigen and helps to counter its effects.
18
Q
What do antibodies do?
A
Antibodies destroy bacteria and viruses, thereby preventing them from entering host cells.
19
Q
where do B and T cells mature?
A
B-bone marrow
T-thymus
20
Q
B cells are responsible for the __________ immune response and T cells for the _______ ___________immune response.
A
B- humoral
T- cell mediated
21
Q
how many B and T cells do we have?
A
100,000
22
Q
what types of cells do B cells produce after exposure? what are their jobs?
A
plasma cells- short lived, secrete antibodies to attack
memory cells- long lived, ready to be activated by a second exposure to the antigen.
23
Q
The first exposure is called a __________ immune response. The next time you are exposed it is a_________ immune response.
A
primary
secondary
24
Q
When a cell becomes infected, “self” proteins will bind to the antigen and present it on the surface of the cell. Once noticed by a helper T cell what will happen?
A
- It will make more copies of itself.
- It will produce signaling molecules to turn on B cells that will produce more antibodies and
- It will activate cytotoxic T cells to kill the infected cells.
25
Cytotoxic T cells kill infected cells in three basic steps - Describe how this works.
1) A cytotoxic T cell binds to an infected cell.
2) Perforin makes holes in the infected cells membrane, and enzymes that promote apoptosis enter.
3) The infected cell is destroyed (lysed).
26
what are T cells
Cells created in the thymus that produce substances that attack infected cells in the body.
27
what are B cells
Cells manufactured in the bone marrow that create antibodies for destroying bacteria and viruses.
28
what is the flu?
respiratory infection caused by influenza.
transported by droplets
contagious 1-4 days before onset and 5 days after first symptoms
can cause secondary illnesses that could lead to death
29
If you are throwing up for a day or so, you have probably caught a ______ and if you have diarrhea a_________
Norovirus
Rotavirus
30
how many people were killed in the spanish and swine flus?
spanish- 500 mill
swine- 20,000
31
what is the most important thing you can do to prevent yourself from becoming sick
wash your hands
32
Does the measles mumps rubella (MMR) vaccine cause autism? Why do people think it does?
No, it does not cause autism whatsoever.
People thought it did due to 8/12 kids having symptoms at the time. It got retracted in 2010 as there was no casual link between MMR vaccine and autism.
33
what are MHC?
Major Histocompatibility Complex molecules.
proteins that recognize our cells as "self"
coded by hundreds of diff alleles
34
There are 3 ways the immune system can "go wrong" and result in disease?
hyperactive immune system
A poorly functioning immune system
An immune system that attacks itself
35
what is a hyperactive imm sys
immune system becomes hypersensitive to regular environment (causes allergies, asthma, eczema)
36
what is a poorly functioning immune system
system fails to recognize irregular cells and allows for their continued growth instead of destruction
causes cancer or AIDS
37
What is an immune system that attacks itself?
system fails to recognize "self", causes Rheumatoid Arthritis, Type I Diabetes, Lupus, Psoriasis, IBD, MS etc.
38
What is an allergy?
imm sys disorder caused by abnormal sensitivity to an antigen
39
what is an allergen?
a substance that causes an allergic reaction OR an antigen that causes an allergy
40
what is first exposure to an allergy called? what are the steps? what is it similar to?
sensitization
1 antigen enters bloodstream
2 B cells make antibodies
3 antibodies attch to mast cell
similar to primary imm response
41
what is later exposure to an allergy similar to?
Secondary immune response
42
What is anaphylactic shock?
a rapid release of inflammatory chemicals from mast cells, rapidly dilates blood vessels (makes them wider), resulting in a potentially fatal drop in blood pressure.
43
What is used to counteract the effects of anaphylactic shock?
epinephrin in epipens
44
what is the Hygiene hypothesis?
bc we live in a relatively clean world in developed countries there is a theory that this may be leading to more allergies Evidence for this hypothesis is that in the developed world we have seen a 3-5% annual increase in various diseases such as allergies
45
what are diseases that result from an overactive immune system?
allergies, asthma, eczema
46
what are examples of diseases from a poorly functioning immune system
AIDS,
chrons
asthma
cancer
hepititis
47
research shows that pollutants can also...
disrupt the imm sys
48
what diseases are when the imm sys attacks itself
arthritis
lupus
diabetes
Chrohn’s Disease
Parkinson’s Disease
49
From a health perspective, why should we care about being overweight or obese or chronic stress?
they are all linked to high blood pressure, physical functioning and mental illness issues. Also heart attacks, strokes, lack of motivation, sleep problems, fatigue etc.
40% of men and 28% of women are overweight (BMI of 25 or more)
Obesity rates have tripled since the 1980s.
20% of Canadians adults are obese (BMI of 30 or more)
50
What is ecology?
the study of how organisms interact with their living (biotic) and non-living (abiotic) environment
51
Abiotic Factors
nonliving
energy sources, water, temp, air
52
Biotic Factors
All the living organisms that inhabit an environment
53
what is the order of ecological study from least to most inclusive
organism, population, community, ecosystem, landscape, biosphere
54
define: population
community
ecosystem
landscape
biosphere
p- group of individuals of same species living in same place.
c- all pops and living organisms in an enviro
e- all living and nonliving things in enviro
l- many ecosys linked by energy, materials, or organisms
b- earth, sum of all ecosys
55
Why is it colder at the poles than the equator?
Sun shines at a low angle near to the Poles so heat is spread over a wider area.
56
What causes our seasons?
the tilt of the earths axis
57
What is the primary driver of our oceanic and atmospheric air currents?
uneven distribution of solar energy on Earth's surface. This energy imbalance causes differences in temperature, pressure, and density, which in turn lead to the movement of air and water masses.
58
How much does temperature change for every 1000 m increase in elevation?
6 degrees C
59
How does the presence of mountains affect precipitation patterns on the windward and leeward sides of
the mountain?
As the air moves up the windward side of a mountain, it cools, and the volume decreases. As a result, humidity increases and orographic clouds and precipitation can develop. When the air descends the leeward side, it warms and is drier because the moisture in the air was wrung out during the ascent.
60
In marine and freshwater ecosystems, what is the photic zone?
p- The photic zone marks the depth at which there is enough light for PS.
61
In marine and freshwater ecosystems, what is the benthic zone?
the bottom sediments. Near shore, these are in the photic zone. Algae and plants can grow
62
In marine and freshwater ecosystems, what is the pelagic zone?
consists of the water column of the open ocean and can be further divided into regions by depth. can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom
63
What is the most diverse marine habitat?
coral reefs
64
What is an estuary?
where a fresh water stream meets the ocean. The nutrients received from the river make estuaries some of the most productive biomes on earth. Estuaries are home to many oysters, crabs, and fish and many animals reproduce there.
65
In the summer, in temperate areas, lakes can stratify, with warmer less dense water on top and colder, more dense water on the bottom. What are the top and bottom layers called?
warm layer- in photic zone, called epilimnion
cold layer- hypolimnion
66
what are the layers of cold and warm water separated by
thermocline, a zone of rapid temperature change
67
when is temp in lakes uniform? what causes this?
spring and fall
caused by overturn, nutrients from the bottom of the lake get mixed around w oxygen
68
What are some benefits of wetlands?
filters nutrients and sediments.
natural water quality improvement
flood protection
shoreline erosion control
69
Terrestrial biomes that are cold and dry =
polar and tundra
70
warmer and more ppn and with less or no permafrost =
boreal forest
71
warmer and wetter than boreal forest =
temperate forest
72
similar temperature to temperate forest, but less water and sometimes fires =
temperate grasslands
73
very dry areas =
deserts
74
The most diverse terrestrial habitat is the _________ __________ which may receive 200-400 cm of rain/year.
tropical forest
74
similar to temperate grasslands but with warmer
temperatures and a more pronounced dry season
savannas
75
what is evaporation
The change of a substance from a liquid to a gas (water off a leaf)
76
Transpiration
the process by which plants give off water vapor through the stomata in their leaves.
77
explain the water cyle
Water evaporates from the ocean surface, the air moves over the land, and rain falls onto the surface of the land.
fallen rain is taken up by plants and excess flows into bodies of water to eventually go back to the ocean.
Water is transpired through
tree/plant leaves and
evaporates from the
surfaces of rivers and
lakes etc., back to the
atmosphere.
any water not taken up will replenish ground water which goes into rivers and lakes.
78
Condensation
The change of state from a gas to a liquid
79
Precipitation
Any form of water that falls from clouds and reaches Earth's surface.
80
what is storage in lakes and oceans
they store water underground
81
Percolation
The downward movement of water through soil and rock due to gravity.
82
Aquifer
A body of rock or sediment that stores groundwater and allows the flow of groundwater.
83
groundwater recharge
A process by which water percolates through the soil and works its way into an aquifer.
84
What is the current population of the earth
8 billion
85
What are the key differences between an oligotrophic and a eutrophic lake?
o- carry low levels of nutrients; have lower productivity and clear water. Oligotrophic lakes can penetrate deeper for photosynthesis
e- carry large amounts of nutrients, have high productivity and carry dark water and are shallow
86
What is eutrophication?
the natural nutrient enrichment of lakes overtime, mostly from runoff of plant nutrients they receive from the surrounding land. As lakes age, they naturally become more eutrophic (nutrient rich) over time.
87
What is cultural eutrophication?
the acceleration of eutrophication by human activities that add plant nutrients to a lake.
88
What does Liebig's Law of the Minimum tell us about the growth of biological organisms?
Growth is usually limited by only one nutrient at a time
89
Which nutrient tends to be most limiting for phytoplankton in freshwater aquatic ecosystems?
phosphorus
90
what are 2 unique features of Lake Winnipeg that may reduce the negative effects of nutrients on the system
relatively shallow and very large, so a lot of waves/mixing = better aeration, which reduces dead zones due to a lack of dissolved oxygen and it also has a relatively low residence time...3.5 years
91
How many outlets does Lake Winnipeg have?
One, The Nelson River
92
Lake Winnipeg is the ____th largest lake in the world.
10th
93
Lake Winnipeg has a very large watershed that is nearly _________ km2.
1 million
94
Did Lake Winnipeg Regulation result in flooding on Lake Winnipeg?
Lake Winnipeg Regulation reduces shoreline flooding and supports Manitoba's energy demand.
95
What was the effect of Lake Winnipeg Regulation on water levels within the lake?
reduced lake levels
96
What 2 key experiments at the Experimental Lakes Area did they do to determine that it is phosphorus that is the key to solving most freshwater eutrophication problems?
Why can't removing nitrogen solve the problem?
They tested carbon and nitrogen together on one lake and carbon, nitrogen and phosphorus on another and the lake that had phosphorus consisted of algae blooms, making the lake green and smell.
Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems. Nitrogen is also the most abundant element in the air we breathe. Nitrogen and phosphorus support the growth of algae and aquatic plants, which provide food and habitat for fish, shellfish and smaller organisms that live in water.
97
While the Red River only contributes about 16% of the water flowing into Lake Winnipeg it contributes approximately ___ % of the phosphorus entering the system.
66-68%
98
Name 5 factors that contribute to the cultural eutrophication of Lake Winnipeg.
1. Climate, more nutrients and flow from the red river
2. cyanobacterial algal blooms increase during periods of hot weather.
3. Erosion in the channel cut into the marsh
4. increase in draining fields quicker by installing tiled drainage systems.
5. The vast majority of P runs off from fields during spring freshet and after major rains, especially in the spring - these were not captured by routine monitoring.
5. Now some evidence to show that P inputs are directly correlated with runoff and that about 98% of P loading to the system occurs in the spring, and fields with intensive agriculture, animal feed lot sand those draining larger communities are contributing a much larger proportion of nutrients than other surrounding areas.
99
List 5 effects of algal blooms on lakes.
- produce toxins;
- Reduce usability of the water;
- Reduce property values;
- Cause anoxic conditions and potentially fish kills;
- Often result in a change from more palatable algal species toeless palatable and often toxic, cyanobacterial species.
100
Name 3 reasons for the poor condition of the Netley Libau Marsh at the south end of Lake Winnipeg.
1. poor filtering
2. The Netley Cut.
3.Common carp that uproot submerged vegetation, increases turbidity and impedes plant growth.
101
What can certain species of cyanobacteria do that most other phytoplanktonic organisms cannot
can harm animals or humans by out competing other phytoplankton
102
According to recent research conducted by the Lake Winnipeg Foundation's Community Based Monitoring Program, when does most of the phosphorus enter the lake?
melting snow, floods, and heavy rainfall events are responsible for most of the phosphorus that is flushed off the land and carried into our waterways.
103
List a few steps we could take to help reduce the eutrophication problem in Lake Winnipeg?
1) keep water on thee land
2) Conserve the boreal forest
3) Setting the standard for water-waste treatment
4) Monitoring our waterways
5) Managing our shorelines
104
What makes a species invasive?
-No/few effective natural predators.
-fast repro
-adapt easily
-harms things
105
What is the primary way that aquatic invasive species are spread to new waterways? (7)
-inter-connecting waterways
-Un-cleaned fishing equipment andgear.
-Release of live bait and bait water.
-Float planes.
-Release of aquarium or water garden water, aquarium pets or plants.
-Migration of wildlife
-Movement of recreational watercraft and water-based equipment from affected to non-infected waterbodies.
106
Name 4 aquatic invasive species in Manitoba.
common carp, zebra mussels, rusty crayfish, spiny waterflea
107
Zebra mussels are different from all of our native mussels because they attach to hard surfaces using...
byssal threads - strong silky fibres that firmly attach zebra mussels to submerged surfaces
108
One female zebra mussel can produce up to this many eggs per year?
1 million
109
Zebra mussel eggs hatch into free-floating _____ larvae that are microscopic. How long are they in this free-floating larval stage until they attach to a substrate?
1) veliger's
2) 2-3 weeks
110
list 6 impacts that zebra mussels have had on other lakes?
1. Increased water clarity and aquatic vegetation growth.
2. increase in toxic algal blooms
3. altered aquatic food webs.
4. Decrease in Lake Whitefish and Walleye populations.
5. Decrease in native mussel populations
6. Reduced recreational potential
7. Clogged intake structures.
8. Increased drag on watercraft
111
When and where in Canada (which lake) were zebra mussels first discovered?
1986, Lake Erie
112
What three things do you have to do with a boat or other watercraft or water toys etc. to prevent transfer of zebra mussels from one location to another?
drain, dry, clean (rinse with hot water) and dispose
113
Name 3 ways mercury can become elevated in bodies of water.
Burning of coal (atmospheric deposition);
Flooded land (dams/hydroelectric developments);
Metal refining - especially gold;
Historic contamination from industry - such as pulp and paper mills that used to bleach paper using chlorine. Mercury was used in the process and was a waste product.
114
The conversion of elemental mercury to ______ mercury results in it becoming much more bioavailable and bioaccumulating in organisms and biomagnifying up the food chain.
methyl mercury
115
Define bioaccumulation
the accumulation of substances, such as pesticides, or other chemicals in an organism
tend to be more soluble in fats than water, tend to be of higher molecular weight, and are generally difficult to metabolize. They also tend to biomagnify up the food chain
116
Define biomagnification
the concentration of toxins in an organism as a result of its ingesting other plants or animals in which the toxins are more widely disbursed.
animals higher in the food chain will have higher concentrations than those lower in the food chain.
117
There are two fish of the exact same species, but one is twice the size of the other - which will have more mercury, the small or large fish?
the large fish (due to the larger fish consuming more mercury)
118
The concentration of mercury would be (higher or lower) in zooplankton than it would be in pike (predatory fish).
lower
119
The amount of mercury released when land is flooded in the creation of reservoirs is dependent on...
the amount of land flooded and its organic carbon content
120
It takes between _________ or even longer for mercury concentrations in fish to drop down to levels experienced prior to flooding.
10-20 years
121
How much mercury did The Reed Paper Company in Dryden Ontario dump into the Wabigoon River (upstream of the Winnipeg River) between 1962 and 1970?
9 tonnes of mercury
122
Even though the mercury contamination entered the river prior to 1970, 90% of the people in this downstream community of _____________ still have symptoms of mercury poisoning 50 years later.
grassy narrows
123
List 5 symptoms of mercury poisoning.
tremors.
headaches.
difficulty sleeping.
impaired sensations.
muscle weakness and twitching.
emotional changes (mood swings, irritability, nervousness)
kidney damage.
breathing difficulties
124
Many people from Grassy Narrows have been diagnosed by Japanese researchers as having______________ disease (which is caused by mercury poisoning).
Minamata disease
125
Over 300 million tons of plastic is produced every year and it is estimated that _________ tons enters the world's oceans each year.
14 million
126
List two reasons why microplastics are bad for aquatic organisms?
reducing food intake, delaying growth, causing oxidative damage and abnormal behavior.
127
Globally, to date, it is estimated that this percentage _______ of plastic that has been produced has NOT been recycled.
91%
128
If we keep on our current path, by 2050 there will be more plastic in the ocean (by mass) than what?
fish
129
Define behaviour.
the way in which an animal or person acts in response to a particular situation or stimulus.
130
How can some behaviours be invisible?
secretion of a stress hormone for example, would still be considered a behaviour, though it is not a visible one.
131
Is behaviour genetic or environmental? What study confirmed this?
Behaviour is not just genetically determined, but environmental cues plays a strong role.
Behaviour was studied by Karl von Frish and Konrad Lorenz of Austria and Niko Tinbergen of the Netherlands in 1973, they studied bees, animal responses to stimuli, and inborn learning.
132
What is a fixed action pattern?
sequences of innate behavior like a dog seeing a cat run away and it feels it has tp chase it, or unchangeable series of actions triggered by a specific stimulus.
133
What is habituation?
an animal eventually stops responding to a repeated stimulus that conveys little or no information
134
What is imprinting?
learning that is limited to a specific time period in an animal's development and is generally irreversible.
learning in animals immediately after birth or hatching to recognize their caregiver for food and protection
135
What is associative learning?
Behavioural change based on linking a stimulus or behaviour with a reward or punishment; includes trial and error learning
136
what is trial and error learning (a type of associative learning)
where an animal learns to associate a positive or negative effect with a behaviour. If the effect is positive, the animal will tend to repeat the behaviour, if it is negative, they will tend to avoid it
137
What is social learning?
learning by observing the behaviour of others. Many predators learn to hunt by
observing and imitating their mothers
138
Define problem solving and cognition
Problem solving is a process of applying past experience to overcome novel situations. Cognition is the process carried out by an animal's nervous system to perceive, store, integrate, and use information gathered by the senses.
139
What are the 3 basic distribution patterns for organisms in a population? Which is most common?
Clumped - unequal distribution of resources, reduce predation; social - Most Common
Uniform - often the result of interactions or territorial behaviour
Random - rare
140
Compare and contrast Type I and Type III Survivorship Curves and provide an example of an organism
that fits into each category
Type I – high survivorship of young; often few offspring and a lot of parental care - human
Type III – low survivorship for very young; often large numbers of offspring with little/no parental care, Many fish, oysters etc.
141
What shape is an exponential growth curve?
J shaped with a drop off after the population is overpopulated
Ideal growing conditions, no limitations, maximal rate of population growth (r).
142
What shape is a logistic growth curve?
S-shaped curve
Organisms that are limited in distribution tend to have an S shaped population curve. The top of the curve = carrying capacity (K).
143
What is K?
Exponential growth phase
144
Under the logistic growth model, what happens to the r (the rate of growth) as the population nears its
carrying capacity?
As the population gets larger and approaches the environment's carrying capacity, resources become more scarce and the growth rate slows.
145
What are the basic characteristics of an r species?
They often offer little to no parental care, have high offspring mortality, short life spans, and small body sizes.
146
What are the basic characteristics of a k species?
long gestation periods lasting several months, slow maturation (and thus extended parental care), and long life spans.
147
What is the demographic shift or demographic transition?
The demographic shift occurs when a population with an originally high birth and death rate (minimal growth) shifts to a low birthrate and death rate.
148
Know how to tell the difference between a rapidly growing, slowly growing, or negatively growing
population by looking at population age structures
if there is a wide base, there are a large number of youth, which means that the population will continue to grow at a pretty rapid pace for some time
if the bottom of the age structure pyramid is small, it suggests reduced or even
“negative growth” i.e., the population is decreasing
149
Based on our ecological footprint it is estimated that we are currently consuming 1.7 Earth's worth of resources every year - is this sustainable?
no we are over capasity
150
Out of all the countries in the world, Canada has the ____________ largest per capita (per person) ecological footprint.
9th
151
Define a biological community.
an interacting group of various species in a common location
A biological community includes all of the populations of organisms living close enough for potential interaction.
152
Biodiversity depends on...
species richness (the number of different species) and relative abundance (the proportional representation of a species in a community)
153
what is interspecific interactions?
relationships with individuals of other species
154
What is compeition?
occurs where the ecological niches of 2 species overlap AND common resource(s) is/are limiting
155
what is predation?
One species (predator +) kills and eats another species (prey -)
156
what is herbivory?
consumption of plant parts or algae by animals
157
what is symbiosis?
is the long-term association of two different species within a community
158
What is mutalism?
when two organisms of different species "work together," each benefiting from the relationship
159
what is parasitism?
one organism, the parasite, lives off of another organism, the host, harming it and possibly causing death. The parasite lives on or in the body of the host.
160
what is commensalism?
a relationship between two species of organisms, such as plants, animals, and fungus, in which one species benefits while the other is unaffected
161
What is competitive exclusion?
one species outcompetes and eliminates the competitor from its niche
162
What is co-evolution?
a series of reciprocal evolutionary adaptations in 2 species. Occurs when a change in one species acts as a new selective force on another species, resulting in it adapting and changing as well
163
what is a primary producer?
(autotrophs), mostly photosynthesizers - bottom of the trophic level - Level 1
164
what is a primary consumer?
(herbivores) many insects, snails, brazing mammals, seed-eating birds etc. -eat only primary producers (level 2)
165
what is a secondary consumer?
eat primaryconsumers, small fish, predators thateat grazing animals etc. (Level 3)
166
what is a tertiary consumer?
consume secondary consumers (Level 4)
167
what is a quaternary consumer?
often highest level in food chain (Level 5)
168
What are scavengers, detritivores, and decomposers and why are they important?
Scavengers - large animals that feed on carcasses/ carrion/Detritivores - eat detritus (decaying organic material such as animalwaste, plant litter, bodies of dead organisms).
Detritivores- feed at alltrophic levels. Millipedes, earthworms etc.
Decomposers - secrete enzymes to digest dead organic material(often the smaller pieces already partially broken down bydetritivores); convert large organic molecules into small organic orinorganic molecules; provide raw materials for producers = completethe cycle. Prokaryotes + fungi in soil, lake bottoms, oceans etc.
they are important because without them there would be an abundance of dead animals building up
169
What is a food web?
consist of a network of interconnecting food chains
170
What is a keystone species?
A species whose impact on its community is much larger than its biomass or abundance would indicate, an organism that helps hold the system together.
171
What is a trophic cascade?
When removal of a predator has effects at more than one trophic level.
172
What are primary and secondary succession?
primary succession:
occurs in an environment without previous life
secondary succession:
occurs in an area that had previously been inhabited but experienced a disturbance, such as a wildfire
173
How do energy and nutrients differ in their flows within the environment?
Chemical nutrients and energy tend to flow in the same direction for most of an ecosystem, but the main difference is that the nutrient cycle is recycled in the ecosystem while the energy flow is ultimately lost from the ecosystem to the universe at large.
174
Based on the pyramid of production, how much usable energy is lost at each level of the food chain?
10X loss of energy with each trophic level
175
rheumatoid arthritis
swelling at joints caused by the immune system sending antibodies that attack the lining of the joints
176
Type I diabetes
The immune system attacks the pancreas and reduces it's ability to make insulin. This leads to elevated blood sugars and possibly blindness, heart, kidney, and neurological diseases etc
177
Lupus
imm sys attacks the body suppressing itself
178
Psoriasis
The immune system stimulates skin cells to reproduce rapidly producing red raised patches
179
Multiple Sclerosis (MS)
where T cells (cell-mediated) respond against a persons own myelin proteins. This damages cells within the brain and spinal column and can be seen on MRIs as plaques(areas of destroyed/damaged tissue)
180
Parkinson's Disease
A progressive disorder of the immune system that affects movement caused by loss of dopamine-producing neurons
181
Amyotrophic Lateral Sclerosis (ALS)
A fatal neurodegenerative disease affecting motor neurons, death is by eventual paralysis of the body as the brain is no longer able to communicate with it, often the face/head affected first
182
Alzheimer's Disease
A type of dementia that causes problems with memory, thinking and behaviour
183
Ischemic Heart Disease
most common - a problem with the circulation of blood to the heart muscle
