Environmental Science. =]

2.  People
in the world go hungry
because:
Food production has not been
increasing as fast as the
human population has
increased.

3.  Manypeople worldwide are
malnourished, in part
because food production is:
Sufficient, but distribution is
inconsistent

4.  Some places on Earth do not
have enough food due to
famine.
Factors that can lead to famine
are:
1. Crop failure and soil loss
2. Unequal distribution of food
3. Drought

5.  The human body uses food
for:
1. A source of energy
2. Asource of materials for
building and maintaining body
tissues

6.  If a person does not receive enough food
or the right types of food they will
become malnourished.
Typical types of malnutrition are:
1. Amino-acid deficiency
2. Diet of mostly vegetables and grains
3. Low calorie consumption

7.  Humans have certain
nutritional requirements that
need to be met. One of those
requirements are:
They must receive 8 essential
amino acids from the proteins
they eat.

8.  What people eat in developed countries
is different than what people in
developing countries eat.
People in developed countries eat more
food and a larger portion of proteins and
fats than people in developing countries.

9.  Different types of food require different
amounts of energy to produce:
A plot of land can produce more food
when it is used to grow:
Plants such as grains and vegetables
because it requires less energy
compared to raising animals for food
consumption.

10.  Researchers hope to improve the
efficiency (raising more food on
less land) of food production by:
Studying plants and other
organisms that have a high yield
(The amount of a crop produced
per hectare or acre)

11.  The types of organisms that researchers
are interested in studying to improve
efficiency are:
Organisms that can thrive in various
climates and that do not require large
amounts of fertilizers, pesticides, or
fresh water

12.  The reasons why people suffer from
malnutrition vary, depending upon
where they live.
Malnutrition usually occurs because of:
1.Poverty
2.War and political strife
3.Transportation problems

13.  Tobe able to feed the people of
the world in 2050:
1.Produce more food
2.Abolish poverty
3.Increase the productivity of
subsistence farmers

14.  Positive and negative affects of the
Green Revolution (increasing the
production of food without increasing
the area of farmland used) are:
Positive
1.New varieties of grains.
2.Large yield crops.
3.Reduce the price of food.
4.Improve the lives of millions of people.

15. Negative
1.Soil degradation (harming the soil
so that it can no longer support the
local ecosystem)
2.Overuse of water, pesticides, and
fertilizers.

16.  The difference between traditional and
modern farming techniques are:
Traditional
1.Plows pushed by farmer or livestock.
2.Organic fertilizers are used to enrich the soil.
3.Fields are irrigated by water flowing through
ditches.
4.Weeds are removed by hand or machine.

17. Modern
1.Machinery is now used to plow the soil
and harvest crops.
2.Syntheticchemical fertilizers are used
instead of manure and plant wastes.
3.Avariety of overhead sprinklers and drip
systems may be used for irrigation.
4.Synthetic chemicals are used to kill
pests.

18. Earth’s available arable land is
being reduced by:
1.Fast growing human populations.
2.Soil erosion.
3.Desertification.

19.  For crops to grow and be plentiful, they
need fertile soil.
Fertile topsoil is composed of:
1.Rock particles
2.Water and air
3.Organic matter, such as dead and
decomposing organisms

20.  Most soil forms when rock is broken into
smaller and smaller fragments by:
1.Wind
2.Water
3.Chemical weathering (when the
minerals in the rock react chemically
with substances such as water to form
new materials)

21.  Other processes that help to produce
fertile topsoil are:
1.Rock particles – supply minerals
2.Fungi and bacteria – decompose dead
plants and organic debris
3.Earthworms, insects, and small animals
– break up the soil and allow air and
water into it

22.  Layers of topsoil from the top to the
bottom:
1.Surface layer – fallen leaves and partially
decomposed organic matter
2.Topsoil – organic matter, living organisms,
and rock particles
3.Zone of leaching - dissolved or suspended
materials moving downward

23. 4. Subsoil – larger rock particles with
organic matter, and inorganic
compounds
5. Rock particles – rock that has
undergone weathering
6. Bedrock – solid rock layer

24.  Unfortunately topsoil is being lost due to
erosion.
Factors that can lead to erosion are:
1.Modern farming techniques – using any
type of machinery loosens the soil which
can then be washed away
2.Irrigation – washes away any soil that is
loose

25.  Not only can soil be lost to erosion it can
also become like a desert over the years.
Farmland may become desertified if:
1.Domestic animals are allowed to overgraze
the land
2.Too many crops are grown on the land
3.Over time the land gradually looses it
fertility
4.No soil left due to erosion

26. The following can be done to help
prevent desertification:
Lettingthe land lie fallow or to
remain unplanted for several years.

27.  Soil can be conserved in several different
ways.
Some methods of soil conservation are:
1. No-till farming
2. Contour plowing
3. Building terraces
4. Drip irrigation

28. No-tilling farming methods include:
1.Crops being harvested without turning
over the soil
2.Seedsof the next crop are planted
among the remains of the previous crop

29. Advantage and disadvantages of no-till
farming include:
Advantages
1.Theremains of the first crop hold the soil in
place while the new crop develops
2.Saves
time compared with conventional
methods
3.Can also reduce soil erosion to one-tenth of
the erosion caused by traditional methods

30. Disadvantages
1.May not be suitable for some crops
2.Soil
that becomes too densely
packed
3.Lower crop yields over time

31.  Irrigation water usually comes from:
Rivers and groundwater

32. Over the years the soil can build up a
concentration of salts, known as
salinization.
Salinization usually occurs because of:
long-term irrigation because when the
groundwater evaporates it leaves behind
salts

33. Ways to reduce salinization include:
1.Usingrainwater instead of groundwater
on crops, because of less salts
2.Useorganic fertilizers in place of
chemical fertilizers, which contain
excess salts and nitrates

34.  Even if a person is successful in obtaining a
high yield of crops, using the least amount of
land, they may still have to deal with pests.
Major crop pests include:
1.Plants, such as weeds
2.Fungi
3.Microorganisms

35.  Pest populations damage plants by:
1.Breeding more rapidly in warmer
climates
2.Becoming resistant to pesticides via
natural selection
3.More successful at ruining crops than
wild plants

36.  Reason why it is easier for pests to
invade crops instead of wild plants are:
 Wild plants grow throughout the
landscape and have a variety of pest
predators that live on or near the plants,
whereas crops grow densely packed
together which makes it easy for pests
to wipe them out faster

37.  To help get rid of pests, farmers have turned
to using pesticides.
Human health concerns regarding pesticide
use include:
1. Cancer rates among children is higher in
areas that use pesticides
2. Nervous system damage
3. Accidental chemical leaks in factories that
make pesticides

38.  Environmental problems
associated with pesticides
include the following:
1.Accumulate in the soil and water
2.Donot break down rapidly into
harmless chemical when they
enter the environment

39.  In order to avoid the problems with
pesticides, farmers are turning towards
biological pest control.
Biological pest control works by:
1. Releasing a pathogen to control insect larvae
2. Breeding plants with natural defenses
3. Interrupting reproductive methods

40.  Tools of biological pest control
include:
1. Pathogens – used to kill the organism
that is the pest
2. Chemical compounds – repel the pest
and physical barriers – tougher skin
3. Plant’s defensive chemicals -
biodegradable

41.  Farmers are also using another type of
pest management known as integrated
pest management.
The goal of integrated pest management
is:
Reduce pest damage to a level that
causes minimal economic damage

42.  Integrated pest management can
include:
1. A mix of farming methods
2. Biological pest control
3. Chemical pest control

43.  Through advances with technology,
farmers are now able to grow crops with
desirable traits.
 The do this through a process known as
genetic engineering.
 Farmers choose to use genetic
engineering:
 In order to get a faster result tha

44.  Genetic engineering of food
crops:
Continues to be debated among
scientists

45.  The following are advantages and
disadvantages of genetic engineering:
Advantages
1. Tastier fruit
2. Pest resistance

46. Disadvantages
1.Products
have not been fully tested for
environmental impacts
2.Geneticallyengineered traits are
accidentally passed on to the wild
plants

47.  An alternative to genetic engineering
include:
Sustainable agriculture

48.  Not only do people get their nourishment
from vegetables, they also get vitamins
and minerals from animals.
 Animals can be wild, domesticated, or
farm raised.
 Just like plants, animals can be
overharvested.

49.  To combat overharvesting, especially
fish, governments have created:
 No-fishing zones, so that fish
populations can recover

50.  A highly used method of harvesting fish
and seafood is known as aquaculture.
 The most common method of
aquaculture is:
Fish farming

51.  The different types of aquaculture
include:
Fish farm – many individual ponds that
each contain fish at a specific stage of
development
Ranch – fish raised until they reach a
certain age and then released

52. The environmental damages that can
occur from aquaculture are:
1.Alarge amount of waste, which can be a
source of pollution
2.Requires so much water that they can
deplete local water supplies

53.  Animals, known as livestock, are raised
for certain products.
Products obtained from livestock include:
1. Leather
2. Wool
3. Eggs and meat

54.  People in developed and developing
countries use livestock for different
reasons.
 The differences between developed and
developing countries and their use of
livestock are:
Developing countries use livestock for
manure and fuel, also for plowing and
pulling carts

55.  Another type of livestock raised is
poultry or chickens, ducks, and geese.
 Chickens are raised for:
Meat and eggs, which are a good source
of essential amino acids

56.  Chickens, ducks, and geese are usually
raised in factory farms.
The criticisms against raising poultry in
factory farms are:
 They live in cramped, artificial
environments

57.  Ducks are being used as part of an integrated
system in which some of their products are
used to help another crop.
Ways in which ducks are used as part of an
integrated system are:
1. Droppings are used to fertilize fields of rice
2. Rice fields are flooded several times a year
with nearby ponds
3. Mulberry trees are irrigated by the ponds

58. The integrated system is beneficial
because:
1.Uses little fresh water
2.Recycles waste
3.Produces ducks, silk, rice and fish