Lesson 2

Animal and Plant Nutrition

PowerPoint® Lecture Presentations for

Biology
Eighth Edition
Neil Campbell and Jane Reece

Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
 Objectives

This lesson aims to:

a. Cite the nutritional requirement of plants and
animals;
b. Enumerate the structures or organs involved in
nutrient
procurement in plants and animals;
c. Trace the pathway of nutrient absorption in plant
and animals;
and
d. Describe the function of each organ of human
digestive system.
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
 What is nutrition?

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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
 Macronutrients and Micronutrients

• A chemical element is considered an essential

element if it is required for a plant to complete its life
cycle.
• Nine of the essential elements are called
macronutrients because plants require them in
relatively large amounts. The macronutrients are
carbon, oxygen, hydrogen, nitrogen, phosphorus,
sulfur, potassium, calcium, and magnesium.
• Eight of the essential elements are called
micronutrients because plants need them in very
small amounts. These are chlorine, iron, manganese,
boron, zinc, copper, nickel, and molybdenum.

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TECHNIQUE
Hydroponic culture - used
by researchers to
determine which chemical
elements are essential

Control: Solution Experimental: Solution

containing all minerals without potassium
The 17 Essential Elements = Micro- and Macro- Nutrients
1. What is an autotroph?
heterotroph?
2. How plants obtain water and
carbon dioxide?
3. What is a micronutrient?
macronutrient?
4. Give an example of
micronutrients/macronutrients and
its major functions.
Symptoms of Mineral Deficiency

• Symptoms of mineral deficiency depend on the

nutrient’s function and mobility within the plant.
• Deficiency of a mobile nutrient usually affects
older organs more than young ones.
• Deficiency of a less mobile nutrient usually
affects younger organs more than older ones.
• The most common deficiencies are those of
nitrogen, potassium, and phosphorus.

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The most common mineral deficiencies, as seen in maize leaves
Health
y

Phosphate-deficient

Potassium-deficient

Nitrogen-deficient
Improving Plant Nutrition by Genetic
Modification: Some Examples
Genetic engineering can improve plant nutrition
and fertilizer usage:
• Resistance to Aluminum Toxicity
• Flood Tolerance
• Smart Plants

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Resistance to Aluminum Toxicity

• Aluminum in acidic soils damages roots and

greatly reduces crop yields.
• The introduction of bacterial genes into plant
genomes can cause plants to secrete acids
that bind to and tie up aluminum.

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Flood Tolerance

• Waterlogged soils deprive roots of oxygen and

cause buildup of ethanol and toxins.
• The gene Submergence 1A-1 is responsible for
submergence tolerance in flood-resistant rice.

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Smart Plants

• “Smart” plants inform the grower of a nutrient

deficiency before damage has occurred.
• A blue tinge indicates when these plants need
phosphate-containing fertilizer.

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Deficiency warnings from “smart” plants

No Beginning Well-developed
phosphorus phosphorus phosphorus
deficiency deficiency deficiency
Plant nutrition often involves relationships with
other organisms
• Plants and soil microbes have a mutualistic
relationship ++
– Dead plants provide energy needed by
soil-dwelling microorganisms.
– Secretions from living roots support a wide
variety of microbes in the near-root
environment.

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Soil Bacteria and Plant Nutrition

• The layer of soil bound to the plant’s roots is

the rhizosphere.
• The rhizosphere has high microbial activity
because of sugars, amino acids, and organic
acids secreted by roots.

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Rhizobacteria

• Free-living rhizobacteria thrive in the

rhizosphere, and some can enter roots.
• Rhizobacteria can play several roles:
– Produce hormones that stimulate plant
growth
– Produce antibiotics that protect roots from
disease
– Absorb toxic metals or make nutrients more
available to roots.
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Bacteria in the Nitrogen Cycle
• Nitrogen can be an important limiting nutrient for plant
growth.
• The nitrogen cycle transforms nitrogen and
nitrogen-containing compounds. Most soil nitrogen
comes from actions of soil bacteria.
• Plants absorb nitrogen as either NO3– or NH4+
• Bacteria break down organic compounds or use N2 to
produce NH3, which is converted to NH4+
• Nitrification is carried out by bacteria that convert NH3
into NO3– .

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The role of soil bacteria in the nitrogen nutrition of plants

Atmosphere N2 N2
Atmosphere

Soil Nitrate and

nitrogenous
organic
compounds
exported in
N2 Nitrogen-fixing bacteria xylem to
Denitrifyin shoot system
H+ g
(from soil) bacteria
NH4+
Soil
NH3 NH4+ NO3–
Ammonifying (ammonia) (ammonium) Nitrifying (nitrate
bacteria bacteria )
Organic material (humus)
Roo
t
Nitrogen-Fixing Bacteria: A Closer Look

• N2 is abundant in the atmosphere, but

unavailable to plants.
• Nitrogen fixation is the conversion of nitrogen
from N2 to NH3.
• Symbiotic relationships with nitrogen-fixing
bacteria provide some plant species with a
built-in source of fixed nitrogen.
• Key symbioses occur between nitrogen-fixing
bacteria and plants, including those in the
legume family (peas, beans, and other similar
plants)
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• Along a legume’s roots are swellings called
nodules, composed of plant cells “infected” by
nitrogen-fixing Rhizobium bacteria.
• Inside the root nodule, Rhizobium bacteria
assume a form called bacteroids, which are
contained within vesicles formed by the root
cell.
• The bacteria of a root nodule obtain sugar from
the plant and supply the plant with fixed
nitrogen ++ mutualism.

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Root nodules on legume plants

Bacteroids
Nodule within
s vesicle

Roots 5 µm

(a) Pea plant root (b) Bacteroids in a soybean

root
nodule
• Each legume species is associated with a
particular strain of Rhizobium.
• The development of a nitrogen-fixing root
nodule depends on chemical dialogue between
Rhizobium bacteria and root cells of their
specific plant hosts.

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 Rhizobium
Infection bacteria
thread
1 Chemical signals 2 Bacteroids form
attract bacteria
Bacteroid
1
Infected root hair
2 Dividing cells
Development in root cortex

of a soybean Dividing cells

root nodule in
pericycle

Developing
root nodule

3 Bacteroid

4
3 Nodul
e
forms

4 Nodule develops
vascular tissue

Nodule
vascular
Bacteroid tissue
Nitrogen Fixation and Agriculture

• Crop rotation takes advantage of the agricultural

benefits of symbiotic nitrogen fixation.
• A non-legume such as maize is planted one year, and
the next year a legume is planted to restore the
concentration of fixed nitrogen in the soil.
• Instead of being harvested, the legume crop is often
plowed under to decompose as “green manure” and
reduce the need for manufactured fertilizer.
• Non-legumes such as alder trees, certain tropical
grasses, and rice benefit either directly or indirectly
from nitrogen-fixing bacteria.

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Fungi and Plant Nutrition

• Mycorrhizae are mutualistic associations of

fungi and roots ++.
• The fungus benefits from a steady supply of
sugar from the host plant.
• The host plant benefits because the fungus
increases the surface area for water uptake
and mineral absorption.
• Mycorrizal relationships are common and might
have helped plants to first colonize land.

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 Epidermis Cortex Mantle 100 µm
(fungal
sheath)

Endodermis

Fungal
hyphae
betwee
Mantle - fungal n
(a)
sheath cortical (colorized SEM)
cells
Ectomycorrhi
zae Epidermi Cortex 10 µm
Cortical cells
s

Endodermis

Fungal Fungal
hyphae vesicle
Casparian
strip
Root
Arbuscules
hair
Plasma
membrane (LM, stained
(b) Endomycorrhizae Arbuscular specimen)
mycorrhizae
In endomycorrhizae, microscopic fungal hyphae extend
into the root

Epidermis Cortex 10 µm
Cortical cells

Endodermi
s
Fungal Fungal
hyphae vesicle
Casparia
n
Root strip
Arbuscules
hair
Plasma
membrane (LM, stained
Arbuscular mycorrhizae (endomycorrhizae) specimen)
 Agricultural and Ecological Importance of
Mycorrhizae
• Farmers and foresters often inoculate seeds
with fungal spores to promote formation of
mycorrhizae.
• Some invasive exotic plants disrupt interactions
between native plants and their mycorrhizal
fungi.

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1. What are some specialized
structures in roots that help in
plant nutrition?
2. Give an example of the
relationship and other organisms
that help in plant nutrition.

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Epiphytes, Parasitic Plants, and Carnivorous
Plants
Some plants have nutritional adaptations that use other
organisms in nonmutualistic ways:
• Epiphyte plants + 0 grows on another plant and
obtains water and minerals from rain.
• Parasitic plants + - absorb sugars and minerals
from their living host plant.
• Carnivorous plants are photosynthetic but obtain
nitrogen by killing and digesting mostly insects.

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Unusual nutritional adaptations in plants

Staghorn fern, an
epiphyte
Unusual nutritional adaptations in plants

Mistletoe, a photosynthetic
parasite
Unusual nutritional adaptations in plants

Host’s phloem
Dodder
Haustoria

Dodder, a nonphotosynthetic
parasite
Unusual nutritional adaptations in plants

Carnivorous plants
Unusual nutritional adaptations in plants
Carnivorous plants

Pitcher plants
Unusual nutritional adaptations in plants
Carnivorous plants

Sundew
s
Review

N (from atmosphere) (to atmosphere) N

2 Nitrogen-fixin H+ 2
g (from soil) Denitrifying NH4+
bacteria bacteria

NH3 NH4+
(ammonia (ammonium
NO3–
Ammonifying ) ) Nitrifying (nitra
bacteria bacteria
te)
Organic
material (humus) Root
1.What is the difference of the
non-mutualistic relationship of
plants nutritional adaptation?
2. What is the difference between
symplast and apoplast route?
3. What is the difference between
xylem and phloem?
You should now be able to:

1. Define soil texture and soil composition.

2. Explain why plants cannot extract all of the
water in soil.
3. Define cation exchange and describe how
plants can stimulate the process.
4. Discuss the problems of topsoil erosion and
farm irrigation in arid regions; suggest actions
that can help mitigate these problems.
5. Distinguish between and list the macronutrients
and micronutrient.s
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 6. Explain how a nutrient’s role and mobility
determine the symptoms of a mineral
deficiency.
7. Summarize the ecological role of each of the
following groups of bacteria: ammonifying,
denitrifying, nitrogen-fixing, nitrifying.
8. Describe the basis for crop rotation.
9. Distinguish between ectomycorrhizae and
arbuscular mycorrhizae.
10. Describe the adaptations for nutrition of
parasitic, epiphytic, and carnivorous plants.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
TYPES OF DIGESTIVE
SYSTEMS
 INVERTEBRATES DIGESTIVE
SYSTEMS
Gastrovascular cavity and is found in organisms with only one
opening for through which food is ingested and waste is
excreted.
PLANARI
A

CORAL
 INVERTEBRATES DIGESTIVE
SYSTEMS
Alimentary canal which is a more advanced system: it consists
of one tube with a mouth at one end and an anus at the other.
SPIDER

GRASSHOP
PER
 FOUR BASIC TYPES OF
VERTEBRATES DIGESTIVE
SYSTEMS
Monogastric
Avian
Ruminant
Pseudo-rumin
ant.
 FOUR BASIC TYPES OF
DIGESTIVE SYSTEMS
Monogastric
digestive system
has one simple
stomach that
secretes acid.
This acid destroys
most bacteria in
the stomach and
break down the
foods into its
simplest form.
They can easily
digest foods with
high in energy
and low in fiber.
 FOUR BASIC TYPES OF
DIGESTIVE
Avian digestive system is foundSYSTEMS
in
poultry, animals that do not have
teeth. They break their food into small
pieces by pecking it with their beaks
esophagus
or scratching them before swallowing.
Food enters the mouth, travels to the crop
liver proventriculus
esophagus, and into the crop. The
gizzard
crop is where the food is stored and pancreas

soaked. The food moves to the

stomach of birds called proventriculus Small intestine
where the gastric enzymes and
hydrochloric acid are secreted. From
there, the food goes to the gizzard, a caeca
very muscular organ, which contains Large intestine

stones that act like teeth to grind the cloaca

food. The food then moves to the

 FOUR BASIC TYPES OF
Ruminant DIGESTIVE
digestive SYSTEMS
system has a large
stomach divided into four
compartments—the rumen,
the reticulum, the omasum,
and the abomasum. They
are herbivores, which eat
large amounts of fiber.
Their digestive system
are able to digest large
amount of cellulose. Their
foods are not chewed well
and are swallowed in large
quantities. The first
compartment of the stomach
is the rumen which has
millions of bacteria and
 FOUR BASIC TYPES OF DIGESTIVE
Pseudo-rumin SYSTEMS
ant digestive
system is found
in animals that
eat large
amounts of fiber
but do not have
stomach with
several
compartments.
The digestive
system has the
same functions
of those of
ACTIVITY 4: WHERE DO YOU
BELONG? GIVEN LIST OF ANIMALS IDENTIFY
THE TYPE OF THEIR DIGESTIVE SYSTEM.

MONOGASTRI AVIAN RUMINANT PSEUDO-

C RUMINANT

AVIAN

MONOGAST
RIC
ACTIVITY 4: WHERE DO YOU
BELONG? GIVEN LIST OF ANIMALS IDENTIFY
THE TYPE OF THEIR DIGESTIVE SYSTEM.

MONOGASTRI AVIAN RUMINANT PSEUDO-

C RUMINANT
PSEUDO-RU
MINANT

RUMINANT
 ACTIVITY 4: WHERE DO YOU
BELONG? GIVEN LIST OF ANIMALS IDENTIFY
THE TYPE OF THEIR DIGESTIVE SYSTEM.

MONOGASTRI AVIAN RUMINANT PSEUDO-

C RUMINANT

hamster

PSEUDO-RU MONOGAST
MINANT RIC
 ACTIVITY 4: WHERE DO YOU
BELONG? GIVEN LIST OF ANIMALS IDENTIFY
THE TYPE OF THEIR DIGESTIVE SYSTEM.

MONOGASTRI AVIAN RUMINANT PSEUDO-

C RUMINANT
earthwor
sheep
m

AVIAN RUMINANT
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The four stages of food processing

Small
molecules

Pieces
of food

Chemical Nutrient
Mechanic digestion molecules
al (enzymatic enter body
digestion hydrolysis) cells

Food Undigeste
d
material

1Ingestion 2 Digestion 3 Absorption 4 Elimination

Mechanical
& Chemical

Digestion
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