Unit 3 Flashcards

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1
Q

What is food security? Give def.

A

The ability of human population to access food of sufficient quality and and quantity.

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2
Q

Human food are mostly sourced from what crops?

A
  • Cereals
  • Potato
  • Roots
  • Legumes
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3
Q

What factors affect plant growth?

A
  • Light availability
  • Nutrients available
  • Water in soil
  • competition with other plants (space)
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4
Q

What happens to light energy in photosynthesis? (Fates of light striking a leaf)

A

Light is:

  • Absorbed
  • reflected
  • transmitted (passed through the leaf)
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5
Q

What happens when light becomes absorbed? (Stage one)

A
  • electrons become excited and energy goes to electron transport system
  • rest of energy used for photolysis (splitting water into hydrogen and oxygen)
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6
Q

What happens to the hydrogen and oxygen in stage one of photosynthesis?

A

Oxygen - released as a by-product.

Hydrogen - bonds with coenzyme NADP to form NAPH which goes to the Calvin cycle.

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7
Q

Does the Calvin cycle require light?

A

The carbon fixation stage does not require light.

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8
Q

What happens in the Calvin cycle? Break into 3 steps.

A

CO2 enters the cycle and becomes attached to RuBP (ribulose biphosphate) to produce 3-phosphoglycerate (3PG)

3-phosphoglycerate is phosphorylated by ATP and combined with hydrogen from NADPH to form G3P (glyceraldehyde-3-phosphate)

G3P is used to regenerate RuBP or can be used to synthesise sugars.

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9
Q

What do the synthesised sugars do?

A

Sugars can be made into starch or cellulose, or passed through pathways to form metabolites.

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10
Q

What does RuBP stand for?

A

Ribulose biphosphate.

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11
Q

How is the CO2 attached to the RuBP?

A

By enzyme RuBisCO.

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12
Q

What does 3PG stand for?

A

3-phosphoglycerate.

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13
Q

What does G3P stand for?

A

Glyceraldehyde-3-phosphate.

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14
Q

What are the types of characteristics scientists would look for in GM plants?

A
  • higher crop yield.
  • higher nutritional value.
  • resistance to pests and disease.
  • ability to thrive in certain environment.
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15
Q

What are plant field trials?

A

Field trials are to investigate a range of different characteristics by plots. (equally divided space)

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16
Q

What is inbreeding?

A

The breeding of two closely related species to breed a desired characteristic. This process is done to eliminate heterozygotes.

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17
Q

Why is inbreeding rarely carried out?

A

There can be negative results, such as:

  • decline in size
  • decline in yield
  • poor vigour
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18
Q

What is crossbreeding?

A

The breeding of two different breeds.

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19
Q

What are annual weeds?

A

Weeds that grow yearly.

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20
Q

What are perennial weeds?

A

Weeds that live for several years. (Jeez.)

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21
Q

What are the pros of annual weeds?

A
  • high seed output.
  • can grow quickly.
  • short life cycle.
  • seeds are viable for a long period of time.
22
Q

What are the pros to perrenial weeds?

A
  • have storage organs for when conditions are poor.
  • already established in the habitat.
  • reproduces asexually.
23
Q

How are diseases passed in plants?

A

Passed by air, soil, or insects.

24
Q

What’s animal welfare? Give def.

A

Animal welfare refers to the wellbeing of an animal: both mentally and physically. This includes the ability of the animal to express its natural behavioural patterns.

25
Q

What are the two types of farming?

A
  • intensive.

- free range.

26
Q

Which type of farming is more expensive to maintain?

A

Free range.

27
Q

Why is free range more expensive to maintain than intensive?

A

Free range requires more land and labour.

28
Q

What are the benefits of intensive farming?

A

More profitable (less money to be spent on labour and land)

29
Q

What are the benefits of free range?

A
  • increased growth of animals.
  • increased success rate of breeding.
  • higher quality end product.
  • animals have a better quality of life.
30
Q

How can poor animal welfare be indicated?

A

Poor animal welfare can be indicated by behavioural patterns.

31
Q

What are the behavioural indicators?

A
  • stereotypy.
  • misdirected behaviour.
  • failure in sexual and parental behaviour.
  • altered levels of activity.
32
Q

What is stereotypy? Give def. How can this be reduced?

A

Stereotypy is when an animal displays repetitive movement.

This can be reduced by increasing the animals’ enclosure.

33
Q

What is misdirected behaviour? Give def.

A

Misdirected behaviour is when normal behaviour is directed at thyself, at others, or in its environment.

E.g a bird plucking its own feathers, gnawing at a rock, or reduced reproductive success.

34
Q

What is failure in sexual and parental behaviour?

A

Sexual; animals stop showing mating behaviours- stops looking for partners.

Parental; Males leave, females abandon, aggressive towards young, or eat and kill them. Some females also steal babies :(

35
Q

What are the altered levels of activity?

A

Very low levels of activity is known as apathy. In this state, animals sit, stand, or lie for long periods of time.

Very high levels of activity is known as hysteria. In this state, animals move a lot and are easily panicked/alarmed.

36
Q

What is symbiosis? Give def.

A

Symbiosis is the relationship of two different species living together.

37
Q

What are the two types of symbiosis?

A
  • parasitism.

- mutualism.

38
Q

What is parasitism?

A

When one species (the parasite) benefits at the expense of the host.

39
Q

What is mutualism?

A

Mutualism is when both species benefit from the relationship.

40
Q

How does the parasite benefit from it’s host?

A

The parasite benefits from its relationship by gaining nutrients/energy from its host.

41
Q

How does the host harmed by parasitism?

A

The host is harmed by losing energy/nutrients.

42
Q

Why do parasites need a host?

A

Parasites have very limited metabolism and cannot survive without a host.

43
Q

How do parasites go from host to host?

A
  • direct contact
  • release of resistant stages (parasites use larvae/pupae to survive as they are resistant to adverse changes)
  • use of a vector
44
Q

Give an example of mutualism.

A

Herbivores: have digesting bacteria which the herbivore will provide an environment for the bacteria will survive. Bacteria will help break down cellulose and provide protein.

Cleaner fish: the cleaner fish eats dead skin cells from sharks. Sharks become cleaner and less prone to infection.

45
Q

Why is pest control important?

A

To prevent diseases from affecting the plant.

46
Q

What can poor pest control lead to?

A
  • decrease in crop yield.

- increased diseases among plants.

47
Q

What are the 3 kinds of pests?

A
  • insects
  • nematodes
  • molluscs
48
Q

What are plant diseases caused by?

A

Fungi, bacteria and/or viruses.

49
Q

What are the chemical controls of plant protection? (Pesticides)

A
  • herbicides
  • fungicides
  • insecticides
50
Q

Plant protection chemicals can be systematic or selective. Describe them both.

A

Selective: kills specific weed/insect/disease.

Systematic: chemicals absorbed by plant.

51
Q

What are the issues with plant protection?

A
  • toxicity towards animal species.
  • persistent in environment.
  • accumulate or magnified in food chains