2. What do we understand by the phrase âform and functionâ of an
organism?
Form = anatomy and morphology
Function = physiology
2
3. To learn about how form and functions go together weâll have to
study the anatomy and morphology of organisms together with
their physiology.
3
4. The cell is an organismâs basic unit of structure
and function - it carries out all activities of life -
and its study is called Cytology.
In multicellular organisms, individual cells are
specialised to perform only part of the function
of the entire organism.
4
5. In multicellular organisms the specialised cells are grouped
together with similar cells having the common structure and
function.
5
These groupings are
called tissues and
their study is known
as Histology.
6. In this presentation weâll be dealing with plant and animal form
and function. The two groups of organisms will be treated
separately as it is more convenient from a study point of view.
6
10. Tissues are groups of cells
having the same function.
In plants we have the
several types including:
Meristem (growth tissues)
Dermal (the skin of the
plant)
Vascular (transport)
Support (giving rigidity to
the plant)
Ground (general purpose)
10
13. Vascular tissues conduct materials throughout the plant.
They onsist of two kinds of conducing tissue that differ in
structure and function:
âxylem
âphloem
Both tissues are
usually found together,
grouped in vascular
bundles with
associated fibres.
13
14. Xylem conducts water and dissolved minerals absorbed from
the soil through the plant. It is made up of vessels that are
connected end to end to move water around quickly.
14
18. The cells conducting the
processed nutrients. Composed
of sieve tube cells and companion
cells. The sieve cells are alive at
maturity but lack a nucleus.
18
21. A vascular bundle. The four large âholesâ are the xylem vessels
while the medium ones are the phloem. Between them, in the
centre of the bundle lies the meristem.
21
22. The Epidermis has numerous functions:
⢠protection against chemical and physical damage, against
injury by animals and infestation by parasites
⢠protection of the plant against desiccation
⢠participation in gas exchange, in secretion of metabolic
compounds and in absorption of water
⢠site of receptors for light and mechanical stimuli that help to
transform signals from the surrounding to the plant
22
24. Plant leaves have stomata, openings that allow carbon
dioxide to enter, which is used for photosynthesis. Stomata
have central openings surrounded by two guard cells. These
cells change the shape of the opening by changing their own
shape.
24
25. Usually stomata are open
during the day and closed at
night, but they can close if the
leaf begins to dehydrate.
25
26. The most abundant cells. They have a relatively simple
structure and may be very different in their functions in the
plant.
Primary Functions:
Storage: Such cells are important
in storing nutrients and starch for
the plant.
Basic metabolism: Most
metabolic processes take place
here (e.g. respiration and
photosynthesis.
26
27. There are various specialised
types of parenchyma. These
include:
Chlorenchyma
Collenchyma
Aerenchyma
Sclerenchyma
.
27
28. This tissue is made up of cells specialised for photosynthesis
and containing numerous chloroplasts.
e.g. much of the tissue which makes up the leaf blade.
28
29. The word comes from Greek "kollaâ (glue). Elongated cells
with unevenly thickened walls that provide structural support
by cementing together the various plant organs. Often found
just beneath the epidermis and having unevenly thickened
walls.
Collenchyma
29
30. This is a tissue having cells with large intercellular air spaces
involved in the exchange of gases in plants.
30
31. A tissue containing cells having greatly thickened walls. There are
2 types of such cells:
31
Sclereids : Are relatively short
cells with variable shapes
which usually occur singly or
in small groups.
Fibres : long thin cells which
typically occur in strands.
Found in all plant structures,
they support and strengthen
tissues which are no longer
growing
35. Anchorage of the plant
Absorption of minerals and water from soil
35
36. The Root System:
⢠is usually underground.
⢠anchors the plant in the soil.
⢠absorbs and then conducts water and minerals
to the stem.
⢠may serve as food storage.
36
41. Usually develops above
ground to elevate the
leaves and flowers from
the soil.
Includes the stem, leaves,
and reproductive organs.
Provides many functions
including:
⢠Photosynthesis
⢠Reproduction
⢠Dispersal
⢠Nutrient uptake
⢠Water conduction
41
54. 54
Leaves modified into spines.
The internal structure of
such spines is different to
that of modified stems.
55. Before turning into spines, young
cactus leaves can be seen as
elongated succulent structures
carrying out photosynthesis, like
any other normal leaf.
55
59. 59
In this case the leaves
are carrying out the
function of petals to
attract insects.
The leaves carry out their
photosynthetic function but
also that of protecting the
stem while it was growing.
62. The flower also known as a bloom or blossom, is the
reproductive structure found in Angiosperms. It contains the
plant's reproductive organs and its function is to produce seeds
through sexual reproduction.
62
64. Flowers are collections of
reproductive and sterile
tissue. Sterile parts of
flowers are the sepals and
petals.
The reproductive parts of
the flower are the stamen
(male, collectively termed
the androecium) and pistil,
often called carpel (the
female parts collectively
termed the gynoecium).
64
65. These structures are known as stamens
and their function is to produce pollen.
65
66. 66
The different structures are collectively known as
the gynoecium and their function is to produce
the ovules which will then be fertilised and
develop into seeds.
69. The sterile parts of the flower are usually distinguished in
petals and sepals. In a "typical" flower the petals are showy
and coloured while the sepals are green and small. When the
sepals and petals are the same size and colour they are called
tepals.
69
70. Flowers can also lack petals altogether. This may be because they
do not need them or because some other structures (e.g.
stamens do the work of the petals)
70
71. Flowers may have radial symmetry (actinomorphic) or bilateral
(zygomorphic).
71
74. Flowers are often grouped together to form inflorescences. On
this sunflower, each numbered stucture is a separate flower.
74
1
2
3
4 5 6 7
8
75. Pollination is an important
step in the reproduction of
seed plants: the transfer of
pollen grains (male gametes)
to the plant carpel, the
structure that contains the
ovule (female gamete). The
receptive part of the carpel is
called stigma.
75
76. Pollination is important because most plants will not produce
fruit if the ovules are not fertilised.
The pollen may be carried
by the wind
or by animals.
76
77. The process of pollination requires pollinators as agents that carry
the pollen grains from the anther to the stigma. Methods of
pollination, categorized by pollinator type, are:
Anemophily: pollination by wind (e.g. in grasses and Conifers)
Entomophily: pollination by insects (e.g. bees and butterflies)
Zoophily: pollination by animals (e.g. hummingbirds or bats)
Hydrophily: pollination by water (in water plants like Ribbonweed )
77
78. Anemophily is a form of pollination whereby pollen is
distributed by wind. Unlike entomophilous and zoophilous
species, anemophilous species do not develop scented flowers,
nor do they produce nectar.
78
79. Entomophily is a form of pollination in
which pollen is distributed by insects,
particularly bees, moths, and beetles.
Entomophilous species frequently evolve
mechanisms to make themselves more
appealing to insects, e.g. brightly
coloured or scented flowers, nectar,
shapes and patterns.
79
80. Pollen grains of entomophilous plants are generally larger than the
fine pollens of anemophilous ones.
80
They usually are of more
nutritional value to insects,
who use them for feed for
brood and inadvertantly
spread them to other
flowers.
81. These are lines that guide the
insect towards the centre of
the flower where pollen and
nectar may be found.
81
Many such lines are
visible to humans but
others are not as insects
utilise a different portion
of the light spectrum.
82. What would appear to us as a featureless yellow flower (centre
photo) becomes very different in the eyes of the insect (right
photo). The insect sees a dark center and lands there. Naturally,
the center of the flower is where the animal needs to go for
food; the sexual parts of the flower also happen to be there.
82
84. Some members of the orchid family present an anatomy in
its floral parts that mimic a female insect. The male insect
then visits the flower and "copulates" with the female. This
movement causes the orchid to get pollinated. This is a
sophisticated way to attract a pollinator, and this orchid
obviously depends on the insect for its seed formation.
84
85. Certain flies are deceived into pollinating flowers whose
odour mimics the decaying flesh in which these flies normally
oviposit.
85
86. Typical carrion flies are uninterested in the flowers, but go to
"expecting" to find rotting protein. Not finding it, they will
leave but before they do they will have picked up the pollen.
86
87. Fly on a Stapeliad flower with pollen bags attached to
its mandibles.
87
88. Pollination by moths is know as sphingophily or phalaenophyly.
The flowers are large, nocturnal, white and with a strong sweet
scent, features that allow moths to find them.
88
89. The moths stay on the wing while inserting their long proboscis
into the deep nectar container. These plant comprise the longest
nectar-bearing flowering tubes known in plants.
89
91. Zoophily is a form of pollination whereby pollen is distributed
by vertebrates, particularly by hummingbirds and bats.
Zoomophilous flowers frequently evolve mechanisms to make
themselves more appealing, e.g. brightly coloured or scented
flowers, nectar, and appealing shapes and patterns.
91
93. 93
Certain plants have their
pollen in special âbagsâ that
attach themselves to the
tongue of nectar-eating
birds.
The brown structure is the pollen bag
shaped to attach itself to a birdâs tongue.
94. Hydrophily is a fairly uncommon form of pollination whereby
pollen is distributed by the flow of waters, particularly in rivers
and streams.
94
Hydrophilous species
fall into two categories:
⢠those that distribute
pollen to the surface
of water
⢠those that distribute
it beneath the
surface.
95. Surface hydrophily has been observed in several species of
pondweed and waterweed.
Species exhibiting true submerged hydrophily include Posidonia
australis and ribbonweed.
95
96.
97. A fruit is the ripened ovary â together with seeds â of a
flowering plant. In many species, the fruit incorporates the
ripened ovary and the surrounding tissues.
97
99. The ovary eventually comes to form a structure surrounding the
seed or seeds and development continues until the seeds have
matured.
99
100. The wall of the fruit, developed from the ovary wall of
the flower, is called the pericarp.
This is often differentiated into three distinct layers
called the exocarp (also known as epicarp), mesocarp
(middle layer), and endocarp (inner layer).
100
103. Animals are incredibly diverse and the study of their form and
function in depth would merit such a length of time that it is
beyond the scope of this presentation.
We will therefore be considering mainly the basic anatomy of
chordates as well as some of their organ systems and
phsyiological processes
103
104. This diagram shows the different level of organisation: from cell
to organ system
104
105. The major tissues of vertebrate animals include epithelia,
connective tissue, nervous tissue, bone, and cartilage.
105
Tissues are assembled
into organs, and organs
work together as organ
systems.
Organ systems undergo
regulation and control to
coordinate their
functions.
107. In vertebrate animals we find four primary tissues:
Epithelial Tissue - lining, secreting
Connective Tissue â joining, holding
Nervous Tissue â conducting electrical impulses
Muscle Tissue - contracting
107
108. Occurs in sheets of tightly packed cells that covers the
body, lines the organs and acts as a protective barrier
One side of the tissue is always bound to an underlying
surface called the basement membrane (basal surface)
On the other side there is a free surface facing either
air or a fluid environment.
108
109. The cells may have different shapes according to their location in
or around the body.
109
111. Locations:
⢠Covers the body
externally
⢠Lines the cavities,
tubes, ducts and
blood vessels inside
the body
⢠Covers the organs
inside body cavities
111
114. Epithelial Tissue functions include:
⢠Protection from physical and chemical injury,
⢠Protection against microbial invasion,
⢠Contains receptors which respond to stimuli,
⢠Filters, secretes and reabsorbs materials
⢠Secretes serous fluids to lubricate structures.
114
115. ⢠Seal surfaces and act as
barriers between two
environments
⢠Function in selective
transport and regulate
exchange of molecules
across the epithelial
sheet
115
116. ⢠All substances that enter or
exit the body must pass
through an epithelium.
⢠Form barriers to mechanical
injury, invading
microorganisms, and fluid loss.
⢠Form secretory glands
116
117. Epithelial tissues act as
barriers between two
environments and take
part in selective
transport and exchange
of molecules across the
epithelial sheet.
117
118. This is a tissue in which groups of cells form secretory glands
(liver, pancreas)
118
119. This tissue consists in scattered cells within an extracellular
matrix (liquid or solid) and its function is mainly to support and
bind other tissues.
E.g.: cartilage, tendons, ligaments, bone, adipose tissue, blood,
collagen
119
120. Connective Tissue is the most abundant & widely distributed
tissue.
Its functions include the following:
⢠Connects, binds and supports structures ( Tendons,
ligaments, etc.)
⢠Protects & cushions organs and tissues,
⢠Insulates (fat)
⢠Transports substances (blood).
120
127. Cross section of normal skeletal muscle from
mouse quadriceps.
127
128. A special kind of connective tissue is bone which has two main
functions:
128
⢠It provides a rigid leverage
point for muscles
⢠It is also involved in the
production of red and
white blood cells in
vertebrates.
129. The entire bone system within an organism is known collectively
as skeleton or endo-skeleton to distinguish it from the hard outer
covering of arthropods.
129
130. 130
Muscle is the most abundant tissue in animals and is
responsible for nearly all types of body movement.
The muscle filaments are made of the proteins actin
(thin) and myosin (thick).
These fibres contract
when stimulated
by a nerve impulse.
131. There are three types of muscle:
⢠skeletal - voluntary,
⢠cardiac â involuntary (found only in the heart),
⢠smooth - involuntary
131
132. Muscle tissue is associated with the bones of the skeleton, the
heart and in the walls of the hollow organs of the body.
Muscle Tissue Functions:
â Movement
â Locomotion
â Maintains posture
â Produces heat
â Facial expressions
â Pumps blood
â Peristalsis
132
133. 133
This is found in voluntary muscles that move the skeleton, being
attached to the different bones. Such muscles are also called
âstriatedâ because of their appearance under the microscope.
134. 134
This type of muscle causes involuntary movements and is
found in internal organs such as walls of blood vessels,
intestine, & other 'hollow' structures and organs in the body.
It is called âsmoothâ to distinguish it from the âstriatedâ
voluntary muscles.
135. 135
This is found only in the heart and the movements are involuntary.
137. The functions of Muscle Tissue include:
Movement Locomotion
Maintaining of posture Production of heat
Facial expressions Pumping of blood
Peristalsis
137
138. The functional unit of this tissue is the neuron (nerve cell). Its
role is to sense stimuli and transmit signals from one part of the
body to another including other neurons, the brain, glands and
muscles.
138
142. There are two types of nervous systems in animals:
⢠The Central Nervous System (CNS)
⢠The Peripheral Nervous System (PNS)
142
143. The Central Nervous System (CNS) is composed of the brain and
spinal cord. The CNS is surrounded by bone: skull and vertebrae.
Fluid and tissue also insulate the brain and the spinal cord.
143
144. The Peripheral Nervous System (PNS)contains only nerves and
connects the brain and spinal cord (CNS) to the rest of the body.
144
145. This can be divided in two
sections:
The Somatic Nervous System â
receives external stimuli and
coordinates body movements
The Autonomic Nervous System
â control organ functions such
as heart rate, digestion,
respiration etc.
145
146. The Somatic Nervous System (SNS) is part of the Peripheral N. S.
146
It includes all nerves
controlling the muscular
system and external
sensory receptors.
External sense organs
(including skin) are
receptors.
Muscle fibres and gland
cells are effectors.
147. The Autonomic Nervous
System is that part of
Somatic sSystem (which, in
turn, is part of the
Peripheral System) and
consists of motor neurons
that control internal organs.
It has two subsystems.
It controls muscles in the
heart and other internal
organs such as the intestine,
bladder, and lung.
147
148. The Autonomic Nervous System is further subdivided into:
The Sympathetic Nervous System, involved in the fight or flight
response.
148
The Parasympathetic
Nervous System,
involved in relaxation.
150. The Sympathetic and
Parasympathetic subsystems
operate against each other.
Both systems innervate the
same organs and act in
opposition, e.g. when an
animal is scared, the
sympathetic system causes the
heart to beat faster; the
parasympathetic system
reverses this effect when the
animal calms down.
150
152. The tissues, organs and organ systems must act in a
coordinated manner
The Endocrine System
Involves glands that produce chemicals called hormones
that are released into the bloodstream and carried to
specific glands
The Nervous System
Neurons transmit information between specific locations
Only three type of cells receive nerve impulses: neuron,
muscle cells, and endocrine cells
152
