For Final Exam Flashcards

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1
Q

The challenge in agriculture is?

A

Producing enough food to sustain everyone; sustaining food production and food security of a growing world population

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2
Q

What impacts crops?

A

Stress impacts crops

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3
Q

How can humans and people in agriculture degrees help with the stress on crops?

A

Build Agro ecosystems that can sustain this stress

Demand for locally grown food

Demand for renewable fuel

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4
Q

What do soil microbiomes do?

A

Soil microbiomes can help us achieve sustainable agro ecosystem designs

  • diversity of bacteria in soil
  • biocontrol and the soil microbiome
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5
Q

What do pesticides do?

A

Pesticides fight diseases but are toxic and end up in our drinking water

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6
Q

Soil biological control can be obtained by?

A

Decomposition and Mycorrhizal fungi

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7
Q

What does mycorrhizal fungi do?

A

Gives crops water and nutrients

  • make up microbiome of the crop
  • attach to roots
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8
Q

What does decomposition do?

A
  • produces soluble sugars, amino acids, phenols
  • proteins break down into peptides
  • ammonia oxidation and nitrification occurs
  • converts organic phosphate into phosphorus
  • microbes are required
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9
Q

Global climate patterns are determined by?

A

By the input of solar energy and earth’s movements in space

The sun warms the atmosphere, land and water

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10
Q

What does the warming of the atmosphere by the sun do for us?

A

It establishes temperature variations, air cycle and water movement as well as water evaporation
Which causes dramatic variation in climate

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11
Q

What are the regional and local effects on climate change?

A
  1. Seasonal variation in climate
  2. Large bodies of water
  3. Mountain ranges
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12
Q

What is seasonality (seasonal variation in climate change)?

A
  • earths tilted axis of rotation and its annual passage of the sun gives earth seasons
  • the changing angle of the sun over the year affects local environments
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13
Q

What do seasonal changes in wind patterns do to the earth?

A

They alter ocean currents sometimes causing the cold water to uprise from deep ocean layers

-This nutrient rich water stimulates growth of surface dwelling phytoplankton and the organisms that feed on them

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14
Q

What are bodies of waters influence on the climate?

A

-ocean currents influence climate along the coast of the continents by heating or cooling overlying air masses that pass across the land

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15
Q

What does the Gulf Stream do?

A

The Gulf Stream carries warm water from the equator to the North Atlantic

Therefore NW Europe is warmer during winter than SE Canada, which is farther south but is cooked by the Labrador current flowing south from Greenland

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16
Q

What does the higher heat capacity of water do?

A

It allows the ocean and large lakes to moderate the climate nearby land

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17
Q

On a hot day what happens to land nearby the ocean?

A

Land is warmer than water, air over the land heats up and rises, drawing a cool breeze from the water across the land

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18
Q

Mediterranean climate is what?

A

Climate pattern also occurs around the Mediterranean Sea, which gives it the name

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19
Q

How do mountains influence climate change?

A

Mountains influence air flow over land

When moist air approaches a mountain, the air rises and cools, releasing moisture on the windward side of the peak

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20
Q

What happens to cool air on mountains?

A

Cool, dry air descends, absorbing moisture and producing a “rain shadow”

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21
Q

What does a rain shadow do?

A

It determined where many deserts are found in the world!
ie) Great Basin and the Mojave of North America
And the Gobi desert of Asia

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22
Q

How do mountains affect local temperature?

A

Mountains affect the amount of sunlight reaching an area and thus the local temperature

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23
Q

Mountains physical differences influence what?

A

They influence species distributions locally

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24
Q

How are high elevation and low elevation communities similar?

A

Every 1000m increase in elevation produces an average temperature drop if approximately 6degrees Celsius

One reason that high elevation communities at one latitude can be similar to those at lower elevations much farther from the equator

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25
Q

What are the several factors that influence microclimate?

A
  1. Casting shade
  2. Altering evaporation from soil
  3. Changing wind patterns
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26
Q

Forest trees affect microclimate by?

A

Forest trees moderate the microclimate below them

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27
Q

What does abiotic mean?

A

Non living factors that affect microclimate

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28
Q

What does biotic?

A

Living factors that affect microclimates

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29
Q

How does climate determine species distributions?

A

The observation that many species are on the live in the face of climate change illustrates the importance of climate in determining species distributions

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30
Q

What is the importance of the soil microbiome, in sustainable food production systems?

A

Preservatives and opportunities

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31
Q

the e.coli lac operon is an example of what?

A

is an example of an induced set of genes.

These genes are responsible for the break down of lactose into sugar used for cellular metabolism

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32
Q

The inducible system of Lac Operon involves what?

A
  1. bacterial DNA
  2. A Repressor
  3. mRNA
  4. and the sugar molecule lactose
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33
Q

what are the three proteins encoded by the Lac Operon?

A
  1. Permease
  2. Beta-galactosidase
  3. transacetylase
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34
Q

what is the function of permease?

A

is a membrane bound protein, when embedded in the plasma membrane it provides a direct root for the lactose outside of the cell to be imported into the cell, occurring at a much greater rate than the original passive transfer of the lactose

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35
Q

what is the function of Beta-galactosidase?

A

breaks the cellular lactose into the simple sugars, glucose and galactose

36
Q

what does a repressor molecule do?

A

it prevents gene expression by binding to the upstream controlling region of bacterial DNA

37
Q

what is lactose?

A

lactose is a sugar which is the the Lac operon’s inducing molecule

38
Q

what happens during the gene expression of Lac Operon?

A
  1. lactose passively enters the e.coli cell
  2. Then binds to the repressor molecule
  3. this binding releases the repressor from the controlling region
  4. allowing RNA polymerase to begin transcription of the Lac Operon on the binding site (aka the promoter)
  5. RNA transcribes Lac operon genes into mRNA
  6. Ribosomes then bind to the mRNA and translate the mRNA to form the three proteins associated with Lac Operon
  7. The 1st protein made is Beta-galactosidase, then permease, and finally transacetylase
  8. Once the concentration of the lactose is greatly reduced by the production of simple sugars by the Beta-galactosidase, the lactose bound to the repressor are released
  9. The repressor re binds to the controlling region and gene expression is halted
39
Q

what is the function of transacetylase?

A

function is still unknown

40
Q

what is the operator?

A

a specific sequence of two dozen nucleotides, where the lac repressor binds to

41
Q

what is the operon?

A

all together, the operator, the promoter and the genes they control, the entire stretch of DNA required for enzyme production for the tryptophan pathway make an OPERON

42
Q

what is the corepressor?

A

tryptophan functions with the repressor protein to switch an operon off

43
Q

what is tryptophan the regulatory gene?

A

as tryptophan accumulates, it inhibits its own production by activating the repressor protein, which binds to the operator blocking transcription

44
Q

how does e.coli cells sense the glucose concentration and relay this information to the genome?

A

the mechanism depends on the interaction of an allosteric regulatory protein: Cyclic AMP (cAMP) and avtivator protein CAP

45
Q

what does the regulatory protein Cyclic AMP (cAMP) and CAP do?

A

it accumulates when glucose is scarce, then the activation protein CAP binds to DNA and stimulates transcription of a gene

46
Q

what is the central nervous system?

A

includes the brain and a longitudinal nerve cord

47
Q

what is the peripheral nervous system?

A

the neurons that carry information into and out of the CNS constitute the PNS

48
Q

what are nerves?

A

neurons bundled together

49
Q

what are sensory neurons?

A

transmit information from eyes and other sensors and detect external stimuli( light, sound,etc)

50
Q

what are interneurons?

A

the information sensed by the sensory neurons is sent to processing centres like the brain. Neurons in the brain interpret the sensory input, taking into account the immediate context and the animals experience. MOST of the neurons in the brain are interneurons

51
Q

what are motor neurons?

A

transmit signals from the brain to muscle cells, causing them to contract

52
Q

the ability of neurons to receive and transmit information is based on?

A

based on a highly specialized cellular organization/ structure of a neuron

53
Q

what is the cell body of neuron?

A

most of a neuron’s organelles, including the nucleus are located in the cell body

54
Q

what are the dendrite of a neuron?

A

numerous highly branched extensions, dendrites receive signals from other neurons

55
Q

what is the axon of neuron?

A

a neuron has a single axon, which is an extension from the cell body that transmits signal to other cells via synaptic terminals

56
Q

what is the axon hillock?

A

is typically where signals that travel down the axon are generated

57
Q

what are synapses?

A

at each branched end of an axon transmits information to another cell at a junction called a SYNAPSE

58
Q

what are neurotransmitters?

A

chemical messengers at most synapses

59
Q

what is a synaptic terminal?

A

the part of each axon branch that forms this specialized junction is called a SYNAPTIC TERMINAL

60
Q

what is a membrane potential of neuron?

A

The attraction of opposite charges across the plasma membrane is a source of potential energy, this charge difference or voltage is the MEMBRANE POTENTIAL

61
Q

what is the resting potential of a neuron?

A

the membrane potential of a resting neuron, one that is not sending a signal.
resting potential is typically -60mv -> -80mv

62
Q

what are ion channels?

A

pores formed by clusters of specialized proteins that span the membrane.
allow ions to diffuse back and forth across the membrane
as ions diffuse through they carry with them units of electrical charge

63
Q

what is equilibrium potential?

A

the magnitude of the membrane voltage at equilibrium for a particular ion

64
Q

what are gated ion channels?

A

ions channels that open or close in response to stimuli

65
Q

the opening and closing of gated ion channels does what?

A

alters the membrane’s permeability to particular ions, which in turn alters the membrane potential

66
Q

what is hyper-polarization?

A

-opening potassium channels increases the membrane’s permeability to K+
-Net diffusion of K+ out of the neuron increases shifting the membrane potential toward -90mV.
This increase in the magnitude of membrane potential is called hyper-polarization

67
Q

what is depolarization?

A
  • opening some other types of ion channels has an opposite effect, making the inside of the cell membrane less negative.
  • A reduction in the magnitude of membrane potential is called DEPOLARIZATION
68
Q

what is graded potential?

A

The response to hyper-polarization or depolarization is simply a shift in the membrane potential. this shift is called a GRADED POTENTIAL

69
Q

what is a neuron action potential?

A

If a depolarization shifts the membrane potential sufficiently the result is a massive change in membrane voltage, called an ACTION POTENTIAL

70
Q

what are voltage-gated ion channels?

A

ion channels that open and close when the membrane potential passes a particular level

71
Q

sodium Na+ channels are voltage-gated ion channels which means?

A

an increased depolarization causes more sodium channels to open, leading to an even greater flow of current. the result is a process of positive feedback

72
Q

what is a neuron threshold potential?

A

action potentials occur whenever depolarization increases the membrane voltage to a particular value, called the THRESHOLD

73
Q

what is step 1 of obtaining an action potential?

A
  1. membrane of the axon is at resting potential, most voltage-gated sodium channels are closed. Some potassium channels are open, but most are closed
74
Q

what is step 2 of obtaining an action potential

A
  1. when a stimulus depolarizes the membrane, some sodium channels open, allowing Na+ to enter, inflow causes further depolarization, which opens more sodium channels via positive feedback
75
Q

where do action potentials occur?

A

within the membrane of the axon of a neuron

76
Q

what is step 3 of obtaining an action potential?

A
  1. depolarization opens most sodium channels, while the potassium channels remain closed, potential surpasses the threshold
    Na+ influx makes inside of membrane positive compared to outside
77
Q

what is step 4 of obtaining an action potential?

A
  1. most sodium channels become inactivated, blocking Na+

potassium channels open permitting K+ outflow, which makes the cell negative again

78
Q

what is step 5 of obtaining a resting potential?

A
  • sodium channels close but some potassium channels are still open (hyperpolarization/refractory period)
    -as the potassium channels begin to close, sodium channels become unblocked(though still closed)
    the membrane returns to its resting state
79
Q

what is the refractory period?

A

the “downtime” when the second action potential cannot be initiated, this is called the REFRACTORY PERIOD

80
Q

what is a myelin sheath?

A

the electrical insulation that surrounds vertebrate axons, speed up the conduction of currents

81
Q

what are myelin sheath produced by?

A

they are produced by to types of glial cells

  1. oligodendrocytes
  2. Schwann cells
82
Q

what are oligodendrocytes?

A

they are found in the CNS

83
Q

what are Schwann cells?

A

they are found in the PNS

84
Q

what are the Nodes of Ranvier?

A

in myelinated axons, voltage-gated sodium channels are restricted to gaps in the myelin sheath, called the NODES OF RANVIER

85
Q

what is saltatory conduction?

A

(from the Latin saltare, to hop or leap) is the propagation of action potentials along myelinated axons leaping from one node of Ranvier to the next node, increasing the conduction velocity of action potentials.