BIO220 Lecture 20

Question 1

Right now, we are in the ___ period

Answer 1

quaternary

Question 2

Quanternary period

Answer 2

• last 2.68 million years

- ice age with alternating glacial & interglacial periods

Question 3

Humans emerged ___ years ago

Answer 3

2 million

Question 4

Agriculture is a ____ phenomenon, which appeared in the last ___ years. This means that it appeared in a ___ period.

Answer 4

post-glacial (Holocene epoch);
10 000;
inter-glacial

Question 5

we are currently living in the ___ epoch of the quaternary period

Answer 5

Holocene

Question 6

early humans evolved & migrated as…

Answer 6

hunter/gatherers

Question 7

One theory of ____ states that __ and homo sapiens are very similar

Answer 7

hominid evolution and dispersal;

Neanderthals

Question 8

What was the last area to be colonized by homo sapiens?

Answer 8

Americas

Question 9

Why are fruits good foods?

Answer 9

They are supposed to be eaten (by animals for dispersal)

Question 10

Why are seeds & tubers good food?

Answer 10

energy-storing organs (complex carbs & sugars)

Question 11

Humans are not adapted for eating plant foods. The foods that we eat has to be…

Answer 11

• high nutritional quality

- less defended

Question 12

___ selection was used to make plants more edible

Answer 12

artificial

Question 13

agriculture evolved ___

Answer 13

independently in different areas

Question 14

cultural component of agriculture

Answer 14

societies have to learn (from older generation) how to store seeds, weed, plant…

Question 15

lentils have symbiotic relationship with ___ to get ___

Answer 15

bacteria;

nitrogen

Question 16

legumes are good sources of…

Answer 16

plant protein

Question 17

which kind of seeds are best for humans? for plants?

Answer 17

humans: seeds that don’t shatter because they are easier to collect
plants: seeds that shatter so it disperses genetic material

Question 18

grasses that we eat

Answer 18

• wheat
• rice
• maize
• barley

Question 19

legumes that we eat

Answer 19

• beans
• lentils
• chick peas

Question 20

fruits that we eat

Answer 20

• tomatoes

- squash

Question 21

What are key evolution innovations for grass agriculture?

Answer 21

• non-shattering seed heads

- amylase evolution

Question 22

ancient agriculture innovations

Answer 22

• fish net
• irrigation channels
• domestication (-> evolution of lactose tolerance)
• plows
• crop rotation, draft animals (Middle Age)
• exchange of crops, animals, technology (1492)
• no more nomadism

Question 23

sedentary culture lead to the development of…

Answer 23

• cities

- agriculture

Question 24

Limits of primitive agriculture

Answer 24

• limited area for growth (temperature > water > NPK)
• edaphic (soil) factors: moisture, fertility
• planting same things in same area -> insects, disease, bad yield

Question 25

Janzen-Connell hypothesis

Answer 25

seeds that fall too close to adult tree will die due to established predators in that area - keeps too many of the same species growing in the same area

Question 26

The first population boom lead to...

Answer 26

famines

Question 27

who made artificial fertilizers?

Answer 27

John Bennet Lawes of Rothamsted (different concentrations of N, P, K, Mg)

Question 28

How was edaphic factors solved by agricultural sciences?

Answer 28

add things to soil to replenish lost nutrients - fertilizer (chemicals) - animal poop add N (organic)

Question 29

Where do organic fertilizers & chemical fertilizers differ?

Answer 29

organic matters will also affect soil texture & water retaining qualities, but chemical ones won't

Question 30

which chemical fertilizers had the best effect?

Answer 30

- nitrates | - ammonia

Question 31

N fertilizers come from...

Answer 31

high nitrate minerals - saltpeter - KNO3 - NaNO3

Question 32

Haber-Bosche process

Answer 32

chemical creation of ammonia | natural gas + atm nitrogen + catalyst + pressure -> ammonia

Question 33

HB process produces ___ ammonia per year, and uses ___% of the world's natural gas supply

Answer 33

500 million tons; | 3-5

Question 34

consequences of HB process

Answer 34

- mining towns abandoned - wars, explosives - 1/2 of N in our bodies is from HB - meat production - 1/2 of world is being fed with N from HB

Question 35

How has new technology overcome previous agriculture limitations?

Answer 35

- irrigation brings water to dry areas - fertilizer supplies soil with nutrients - industrial chemistry makes fertilizer

Question 36

Life history theory of plants: how has this been affected by new agricultural technologies?

Answer 36

plant allocations can all go towards seed production because humans prevent competition, insect attacks, need for nutrients

Question 37

life history of plants

Answer 37

plants allocate resources to: - growth (tall = more light, better seed dispersal) - competition - defense - reproduction - dispersal - root system: more water & nutrients

Question 38

plant-breeding techniques

Answer 38

- artificial selection | - hybridization

Question 39

the Green Revolution

Answer 39

- used plant breeding techniques to evolve high-yielding dwarf crop varieties (HYV) - high-intensity cultivating techniques

Question 40

HYV

Answer 40

high yielding dwarf varieties

Question 41

IR8

Answer 41

a semi-dwarf rice variety that could produce more grains of rice per plant when grown with certain fertilizers and irrigation

Question 42

who founded the Green Revolution?

Answer 42

Borlaug

Question 43

HYV are unable to...

Answer 43

detect neighbours | - when plants detect neighbours, they grow tall and skinny

Question 44

Green Revolution techniques lead to a...

Answer 44

exponential rise in yield, but began leveling in mid-1990s | - Green Revolution techniques can't keep up with human growth anymore

Question 45

Now that yields have began to level, how to we support a still-increasing population?

Answer 45

GMO?

Question 46

Consequence of babying plants

Answer 46

- labour intensive - use exhaustible natural resources w/ limited supplies - pollution to surrounding areas (groundwater, poison non-target organsims) - biocides develop superbugs, addictive

Question 47

what is the preferred antibiotic nowadays? Why?

Answer 47

Z-pak; | penicillin is so resistant that it can't be used anymore

Question 48

why don't plants need to worry about competition anymore?

Answer 48

- herbicides | - mechanized cultivation

Question 49

why don't plants need extensive roots anymore?

Answer 49

- irrigation | - fertilizers

Question 50

why don't plants need defense anymore?

Answer 50

- insecticides | - fungicides

Question 51

cultivation & irrigation leads to long-term...

Answer 51

degradation of soils (build-up of salt)

Question 52

which is better: annual wheat vs. perennial wheat

Answer 52

annual wheat: good for people | perennial wheat: good for plant

Question 53

annual wheat

Answer 53

Only lives for 1 year - Shallow root system - More yield - Susceptible to disturbances

Question 54

Perennial wheat

Answer 54

Lives for long time - Extensive root that can provide soil structure - More resilient to disturbances - But less yield

Question 55

2 types of maize production

Answer 55

1. slash & burn | 2. mechanized

Question 56

slash & burn vs. mechanized costs & yield

Answer 56

cost: mechanized so much more labour and material intensive yield: mechanized 4x more ...but is it worth it?

Question 57

modern agriculture depends on..

Answer 57

energy subsidies

Question 58

cost of food is tied to...

Answer 58

cost of petroleum & electricity

Question 59

why is cost of food going up?

Answer 59

we are adding so much stuff in our food to improve yield

Question 60

with current technology, increasing food supply requires...

Answer 60

burning more fuel & clearing more land

Question 61

N, P, K: what is limited?

Answer 61

P & K | P is mined, and very scarce