Energy Transfer And Nutrient Cycles Flashcards

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1
Q

What does abiotic mean?

A

Non living

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2
Q

Give to uses of the sugars produced in plants during photosynthesis

A
  1. Used in respiration for growth

2. To make cellulose

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3
Q

What is biomass?

A

Biomass is the chemical energy stored in the plant

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4
Q

What is dry mass?

A

Dry mass is the mass of the organism with the water removed

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5
Q

How do you measure dry mass?

A
  1. Organism is dried, often in an oven at a low temperature
  2. Weigh organism at regular intervals (e.g. Once a day at 2pm)
  3. When mass becomes constant, organism is dried
  4. Mass of carbon present is 50% of dry mass
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6
Q

How can calorimetry be used to estimate the amount of chemical energy stored in biomass

A

Burn biomass in a calorimeter. The amount of heat given off tells you how much energy is in it. A sample of dry biomass is burnt and the energy released is used to heat a known volume of water. The change in temperature of the water is used to calculate the chemical energy of the dry biomass

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7
Q

What is gross primary production?

A

The total amount of chemical energy converted from light energy by plants, in a given area, in a given time

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8
Q

What is respiratory loss?

A

The amount of energy lost to the environment as heat when plants respire

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9
Q

What is net primary production?

A

The energy left in the organism after respiratory loss

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10
Q

What is the primary production formula?

A

NPP = GPP - R

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11
Q

How to calculate net production

A

N = I - (F + R)

N = net production
I = chemical energy in ingested food
F = chemical energy lost in faeces and urine
R = energy lost through respiration
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12
Q

Efficiency of energy transfer equation

A

% efficiency of energy transfer = (net production of trophic level/net production of previous trophic level) x 100

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13
Q

How to increase efficiency of food webs

A

The energy lost to other organisms can be reduced through the simplification of food webs

The energy lost through the respiration of livestock can be reduced

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14
Q

How do farmers remove pests?

A

Chemical pesticides

Biological agents

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15
Q

How do farmers reduce respiratory loss in live stock?

A

Kept in pens to restrict movement

Pens inside so it’s warm so no energy is wasted by generating body heat

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16
Q

What do Saprobionts do?

A

They feed on the remains of dead plants and animals and on their waste products, breaking them down.

Saprobionts secrete enzymes and digest their food externally then absorb the nutrients they need. During this process, organic molecules are broken down into inorganic ions.

17
Q

What is extracellular digestion?

A

When a decomposer secretes enzymes and digest their food externally and then absorb the nutrients they need

18
Q

What is mycorrihizae?

A

The symbiotic relationship formed between fungi and plant roots

19
Q

How do fungi attach to plant roots

A

Fungi are made up of long thin strands called hyphae. The hyphae connect to the plants roots

20
Q

How does mycorrhizae benefit each organism?

A

The hyphae in the fungi greatly increase the surface area of the plants root system, helping the plant to absorb ions from the soil that are usually scarce. Hyphae also increase the uptake of water by the plant.

Fungi obtain organic compounds, such as glucose, from the plant

21
Q

What are the steps involved in the nitrogen cycle?

A

Nitrogen fixation
Ammonification
Nitrification
Denitrification

22
Q

What is nitrogen fixation?

A

Nitrogen fixation is when nitrogen gas in the atmosphere is turned into nitrogen containing compounds.

23
Q

How is biological nitrogen fixation carried out?

A

Biological nitrogen fixation is carried out by bacteria such as Rhizobium. It turns nitrogen into ammonia. The ammonia can then be used by plant

24
Q

Explain the mutualistic relationship between rhizobium and plants

A

Rhizobium are found inside root modules of leguminous plants. They provide the plant with nitrogen compounds and the plant provides them with carbohydrates

25
Q

What is ammonification?

A

Ammonification is when nitrogen compounds from dead organisms are turned into ammonia and ammonium ions by Saprobionts. Animal waste also contains nitrogen compounds. These are also turned into ammonia and ammonium ions by Saprobionts

26
Q

What is nitrification?

A

Nitrification is when ammonia and ammonium ions in the soul are changed into nitrogen compounds that can then be used by plants. First nitrifying bacteria called Nitrosomonas change ammonia and ammonium ions into nitrates. Then other nitrifying bacteria called Nitrobacter change nitrites into nitrates

27
Q

What is denitrification?

A

Denitrification is when nitrates in the soil are converted into nitrogen gas by denitrifying bacteria via anaerobic respiration

28
Q

Phosphorus Cycle

A

Phosphate ions in rocks are released into the soul by weathering
Phosphate ions are taking into plants through roots
Phosphate ions are passed through food chain as animals each plants and one another
Phosphate ions are lost from the animals in waste products
When plants and animals die, Saprobionts break them down, as well as their waste products, said the releasing phosphate ions into the soil for assimilation by plants
Weathering of rocks release phosphate ions into sea, lakes and rivers
Aquatic producers take up phosphate ions
Phosphate ions passed on to sea birds after consuming fish
Sea birds produce guano waste that releases phosphate ions into the soil