Structural Organisation in Animals Practice Questions - DPP for NEET

 Page 1


Solution
1. (c)
The head is triangular in shape which lies
anteriorly at right angles to the longitudinal body
axis. The head is formed by the fusion of six
segments. The flexible neck facilitates movement
in all directions.
2. (b)
The development of cockroach is
paurometabolous meaning that their development
is through nymphal stage. The nymphs look very
much like adults. The nymph grows by moulting
about 13 times to reach adult form. The last
nymphal stage has wingpads while adult
cockroaches have wings.
3. (c)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of dense regular connective tissues
in which collagen fibres are present in rows
between many parallel bundles of fibres.
4. (b)
Muscle tissue plays the vital role of providing
movement and heat generation to the organs of
the body. Muscle cells are specialized for
contractility and electrical conductivity.
5. (d)
In all connective tissue except blood (a fluid
connective tissue), the cells secrete fibres of
structural proteins called collagen or elastin.
6. (b)
A neuron (also known as a neurone or nerve
cell) is an electrically excitable cell that
processes and transmits information through
electrical and chemical signals. These signals
between neurons occur via synapses, specialized
connections with other cells. A typical neuron
possesses a cell body (soma), dendrites, and an
axon.
7. (d)
Cartilage is a type of connective tissue which is
present in human external ears, the nose tip,
ribcage joints, etc.
8. (d)
Cells of smooth muscle tissue are spindle shaped
and pointed at their ends. Striations are absent
due to different arrangement of actin and myosin
filaments. Smooth muscle is the earliest form of
muscle to evolve.
9. (a)
Cardiac muscles are involuntary, cross striated
& non-fatigued fibres. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its
neighbouring cells are also stimulated to contract.
10. (d)
Smooth muscle is an involuntary, spindle shaped,
uninucleated, tapering and non-striated muscle. Smooth
muscle is responsible for the contractility of hollow
organs, such as blood vessels, the gastrointestinal tract,
the bladder, or the uterus. Its structure differs greatly
from that of skeletal muscle, although it can develop
isometric force per cross sectional area which is equal
to that of skeletal muscle.
11. (c)
Loose connective tissue has cells and fibres loosely
arranged in a semi-fluid ground substance, for example,
areolar tissue present beneath the skin. It serves as a
support framework and specialised to store fats.
12. (d)
NCERT figure 7.18
Label 3 and 4 are respectively genital chamber and
vestibulum which is collectively called genital pouch.
13. (b)
(II) Products of exorine glands are released
through ducts or tubes.
14. (b)
On the basis of the mode of pouring of secretion, gland
are divided into – (a) exocrine, and (b) endocrine glands.
Exocrine glands secrete mucus, saliva, oil, digestive
enzymes and other cell products. These products
are released through ducts or tubes. In contrast,
endocrine glands do not have ducts. Their products
called hormones are secreted directly into the fluid
bathing the gland.
15. (d)
NCERT figure 7.7(a)
Locomotion (performed by limbs) in humans depends
on the movements of muscle fibres. Skeletal muscles
are attached to the bones by tendons and help in the
movement of the parts of skeleton. These muscles
are under the control of conscious mind and are called
voluntary muscles. Under the microscope, these
muscles show transverse stripes and hence are
designated as striated muscles.
Page 2


Solution
1. (c)
The head is triangular in shape which lies
anteriorly at right angles to the longitudinal body
axis. The head is formed by the fusion of six
segments. The flexible neck facilitates movement
in all directions.
2. (b)
The development of cockroach is
paurometabolous meaning that their development
is through nymphal stage. The nymphs look very
much like adults. The nymph grows by moulting
about 13 times to reach adult form. The last
nymphal stage has wingpads while adult
cockroaches have wings.
3. (c)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of dense regular connective tissues
in which collagen fibres are present in rows
between many parallel bundles of fibres.
4. (b)
Muscle tissue plays the vital role of providing
movement and heat generation to the organs of
the body. Muscle cells are specialized for
contractility and electrical conductivity.
5. (d)
In all connective tissue except blood (a fluid
connective tissue), the cells secrete fibres of
structural proteins called collagen or elastin.
6. (b)
A neuron (also known as a neurone or nerve
cell) is an electrically excitable cell that
processes and transmits information through
electrical and chemical signals. These signals
between neurons occur via synapses, specialized
connections with other cells. A typical neuron
possesses a cell body (soma), dendrites, and an
axon.
7. (d)
Cartilage is a type of connective tissue which is
present in human external ears, the nose tip,
ribcage joints, etc.
8. (d)
Cells of smooth muscle tissue are spindle shaped
and pointed at their ends. Striations are absent
due to different arrangement of actin and myosin
filaments. Smooth muscle is the earliest form of
muscle to evolve.
9. (a)
Cardiac muscles are involuntary, cross striated
& non-fatigued fibres. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its
neighbouring cells are also stimulated to contract.
10. (d)
Smooth muscle is an involuntary, spindle shaped,
uninucleated, tapering and non-striated muscle. Smooth
muscle is responsible for the contractility of hollow
organs, such as blood vessels, the gastrointestinal tract,
the bladder, or the uterus. Its structure differs greatly
from that of skeletal muscle, although it can develop
isometric force per cross sectional area which is equal
to that of skeletal muscle.
11. (c)
Loose connective tissue has cells and fibres loosely
arranged in a semi-fluid ground substance, for example,
areolar tissue present beneath the skin. It serves as a
support framework and specialised to store fats.
12. (d)
NCERT figure 7.18
Label 3 and 4 are respectively genital chamber and
vestibulum which is collectively called genital pouch.
13. (b)
(II) Products of exorine glands are released
through ducts or tubes.
14. (b)
On the basis of the mode of pouring of secretion, gland
are divided into – (a) exocrine, and (b) endocrine glands.
Exocrine glands secrete mucus, saliva, oil, digestive
enzymes and other cell products. These products
are released through ducts or tubes. In contrast,
endocrine glands do not have ducts. Their products
called hormones are secreted directly into the fluid
bathing the gland.
15. (d)
NCERT figure 7.7(a)
Locomotion (performed by limbs) in humans depends
on the movements of muscle fibres. Skeletal muscles
are attached to the bones by tendons and help in the
movement of the parts of skeleton. These muscles
are under the control of conscious mind and are called
voluntary muscles. Under the microscope, these
muscles show transverse stripes and hence are
designated as striated muscles.
16. (d)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
17. (d)
Squamous epithelium is formed of thin discoidal
and polygonal cells that fit like tiles in a floor, so
is also called pavement epithelium. It is found in
the walls of blood vessels, in the alveoli of lung
for exchange of gases, and in Bowman’s capsule
of nephron for ultra filtration.
18. (c)
Mast cell are a cell found in connective tissue that
contains numerous basophilic granules and release
substances such as heparin and histamine in
response to injury or inflammation of tissues.
19. (a)
There are three ganglia lie in the thorax, and six
in the abdomen. Each eye consists of about 2000
hexagonal ommatidia.
20. (c)
Keratinised squamous:- This epithelium occurs
in the epidermis of the skin of land vertebrates.
Squamous epithelium:- This epithelium is present
in the terminal bronchioles, blood vessels, alveoli
of the lungs, etc.
Columnar epithelium:- This epithelium lines the
stomach, inner surface of the gall bladder, intestine
and bile duct. It has a secretory role and is called
glandular epithelium.
Ciliated epithelium:- This epithelium lines most of
the respiratory tract and Fallopian tubes
(oviducts). These cells comprise columnar cells
which have cilia on the free surface.
Cuboidal epithelium:- Is present in small salivary
and pancreatic duct. These cells of cuboidal
epithelium are cubical and more or less squarish
in shape.
21. (d)
Basement membrane is a thin extracellular
supporting layer that separates a layer of epithelial
cells from the underlying lamina propria and is
composed of the basal lamina and reticular lamina
22. (a)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
23. (c)
Gland is an organ in the human or animal body
which secretes particular chemical substances for
use in the body or for discharge into the
surroundings.
24. (d)
Plasmodesmata are narrow channels that act as
intercellular cytoplasmic bridges to facilitate
communication and transport of materials
between plant cells. Adhering, tight and gap
junctions are specialized junctions that provide both
structural and functional links between the
individual cells of animal tissues.
25. (a)
Intestine is lined by glandular epithelium which is
secretory in function. The glands found in
intestine are exocrine and may be unicellular or
multicellular. When unicellular glands secrete
mucus, they are called mucous cells or goblet cells
and are common in the columnar epithelium of
intestine. When unicellular glands secrete a clear
watery fluid, they are called serous cells which
are also present in intestinal glands. On the other
hand, multicellular glands consist of a duct and
secretory portion, both formed of epithelial cells.
They are further of two types: tubular and
saccular. In tubular glands secretory portion is
tube like, for example, Crypts of Lieberkuhn (a
type of simple straight tubular glands found in
intestine) and Brunner’s gland (a type of simple
branched tubular glands found in intestine).
26. (a)
Both statements are correct.
27. (c)
All connective tissue is derived from mesoderm,
the middle germ cell layer in the embryo.
Connective tissue is made up of fibers forming a
framework and support structure for body tissues
and organs.
28. (d)
All connective tissue consists of three main
components: fibres (elastic and collagenous
fibres), ground substance and cells. But blood and
lymph lack the fibre component.
29. (b)
Females lack a pair of short, thread-like anal
styles that males have. The male cockroach's
anal/caudal styles emerge from the 9th abdominal
segment.
Page 3


Solution
1. (c)
The head is triangular in shape which lies
anteriorly at right angles to the longitudinal body
axis. The head is formed by the fusion of six
segments. The flexible neck facilitates movement
in all directions.
2. (b)
The development of cockroach is
paurometabolous meaning that their development
is through nymphal stage. The nymphs look very
much like adults. The nymph grows by moulting
about 13 times to reach adult form. The last
nymphal stage has wingpads while adult
cockroaches have wings.
3. (c)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of dense regular connective tissues
in which collagen fibres are present in rows
between many parallel bundles of fibres.
4. (b)
Muscle tissue plays the vital role of providing
movement and heat generation to the organs of
the body. Muscle cells are specialized for
contractility and electrical conductivity.
5. (d)
In all connective tissue except blood (a fluid
connective tissue), the cells secrete fibres of
structural proteins called collagen or elastin.
6. (b)
A neuron (also known as a neurone or nerve
cell) is an electrically excitable cell that
processes and transmits information through
electrical and chemical signals. These signals
between neurons occur via synapses, specialized
connections with other cells. A typical neuron
possesses a cell body (soma), dendrites, and an
axon.
7. (d)
Cartilage is a type of connective tissue which is
present in human external ears, the nose tip,
ribcage joints, etc.
8. (d)
Cells of smooth muscle tissue are spindle shaped
and pointed at their ends. Striations are absent
due to different arrangement of actin and myosin
filaments. Smooth muscle is the earliest form of
muscle to evolve.
9. (a)
Cardiac muscles are involuntary, cross striated
& non-fatigued fibres. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its
neighbouring cells are also stimulated to contract.
10. (d)
Smooth muscle is an involuntary, spindle shaped,
uninucleated, tapering and non-striated muscle. Smooth
muscle is responsible for the contractility of hollow
organs, such as blood vessels, the gastrointestinal tract,
the bladder, or the uterus. Its structure differs greatly
from that of skeletal muscle, although it can develop
isometric force per cross sectional area which is equal
to that of skeletal muscle.
11. (c)
Loose connective tissue has cells and fibres loosely
arranged in a semi-fluid ground substance, for example,
areolar tissue present beneath the skin. It serves as a
support framework and specialised to store fats.
12. (d)
NCERT figure 7.18
Label 3 and 4 are respectively genital chamber and
vestibulum which is collectively called genital pouch.
13. (b)
(II) Products of exorine glands are released
through ducts or tubes.
14. (b)
On the basis of the mode of pouring of secretion, gland
are divided into – (a) exocrine, and (b) endocrine glands.
Exocrine glands secrete mucus, saliva, oil, digestive
enzymes and other cell products. These products
are released through ducts or tubes. In contrast,
endocrine glands do not have ducts. Their products
called hormones are secreted directly into the fluid
bathing the gland.
15. (d)
NCERT figure 7.7(a)
Locomotion (performed by limbs) in humans depends
on the movements of muscle fibres. Skeletal muscles
are attached to the bones by tendons and help in the
movement of the parts of skeleton. These muscles
are under the control of conscious mind and are called
voluntary muscles. Under the microscope, these
muscles show transverse stripes and hence are
designated as striated muscles.
16. (d)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
17. (d)
Squamous epithelium is formed of thin discoidal
and polygonal cells that fit like tiles in a floor, so
is also called pavement epithelium. It is found in
the walls of blood vessels, in the alveoli of lung
for exchange of gases, and in Bowman’s capsule
of nephron for ultra filtration.
18. (c)
Mast cell are a cell found in connective tissue that
contains numerous basophilic granules and release
substances such as heparin and histamine in
response to injury or inflammation of tissues.
19. (a)
There are three ganglia lie in the thorax, and six
in the abdomen. Each eye consists of about 2000
hexagonal ommatidia.
20. (c)
Keratinised squamous:- This epithelium occurs
in the epidermis of the skin of land vertebrates.
Squamous epithelium:- This epithelium is present
in the terminal bronchioles, blood vessels, alveoli
of the lungs, etc.
Columnar epithelium:- This epithelium lines the
stomach, inner surface of the gall bladder, intestine
and bile duct. It has a secretory role and is called
glandular epithelium.
Ciliated epithelium:- This epithelium lines most of
the respiratory tract and Fallopian tubes
(oviducts). These cells comprise columnar cells
which have cilia on the free surface.
Cuboidal epithelium:- Is present in small salivary
and pancreatic duct. These cells of cuboidal
epithelium are cubical and more or less squarish
in shape.
21. (d)
Basement membrane is a thin extracellular
supporting layer that separates a layer of epithelial
cells from the underlying lamina propria and is
composed of the basal lamina and reticular lamina
22. (a)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
23. (c)
Gland is an organ in the human or animal body
which secretes particular chemical substances for
use in the body or for discharge into the
surroundings.
24. (d)
Plasmodesmata are narrow channels that act as
intercellular cytoplasmic bridges to facilitate
communication and transport of materials
between plant cells. Adhering, tight and gap
junctions are specialized junctions that provide both
structural and functional links between the
individual cells of animal tissues.
25. (a)
Intestine is lined by glandular epithelium which is
secretory in function. The glands found in
intestine are exocrine and may be unicellular or
multicellular. When unicellular glands secrete
mucus, they are called mucous cells or goblet cells
and are common in the columnar epithelium of
intestine. When unicellular glands secrete a clear
watery fluid, they are called serous cells which
are also present in intestinal glands. On the other
hand, multicellular glands consist of a duct and
secretory portion, both formed of epithelial cells.
They are further of two types: tubular and
saccular. In tubular glands secretory portion is
tube like, for example, Crypts of Lieberkuhn (a
type of simple straight tubular glands found in
intestine) and Brunner’s gland (a type of simple
branched tubular glands found in intestine).
26. (a)
Both statements are correct.
27. (c)
All connective tissue is derived from mesoderm,
the middle germ cell layer in the embryo.
Connective tissue is made up of fibers forming a
framework and support structure for body tissues
and organs.
28. (d)
All connective tissue consists of three main
components: fibres (elastic and collagenous
fibres), ground substance and cells. But blood and
lymph lack the fibre component.
29. (b)
Females lack a pair of short, thread-like anal
styles that males have. The male cockroach's
anal/caudal styles emerge from the 9th abdominal
segment.
30. (c)
i. Tight junctions: These junctions are formed
by adjacent epithelial cells which are tightly
packed together. These junctions help
prevent substances from leaking across the
tissue.
ii. Gap junctions: These junctions are formed
by connecting the cytoplasm of adjoining
cells. This facilitate cells to communicate with
each other.
iii. Adherens junctions: These junctions cement
the adjacent cells together. They serve
anchoring function.
31. (a)
Squamous epithelium is an epithelium whose
most superficial layer consists of flat, scale-like
cells called squamous epithelial cells. The
epithelium may be composed of one layer of
these cells, in which it is referred to as simple
squamous epithelium or it may possess multiple
layers, referred to as stratified squamous
epithelium.
32. (b)
Connective tissue is a group of tissues in the body
that maintains the form of the body and its organs
and provides cohesion and internal support. The
connective tissues include several types of fibrous
tissue that vary only in their density and cellularity,
as well as the more specialized and recognizable
variants-bone, ligaments, tendons, cartilage, and
adipose (fat) tissue.
33. (b)
All the given statements are associated with
bone. Bone is a rigid body tissue consisting of
cells embedded in an abundant, hard
intercellular material. This material consists of
two important components - collagen and
calcium phosphate. It forms the major portion
of the human skeleton. Bone support and
protect the various organs of the body, produce
red and white blood cells, store minerals and
also enable mobility.
34. (b)
The smooth muscle fibres are involuntary, taper
at both ends and do not show striation. The wall
of internal organs such as the blood vessels,
stomach and intestine contains this type of muscle
tissue.
35. (a)
A. Exocrine glands are ducted glands i.e., these
glands are provided with ducts to transport their
secretions. E.g., salivary glands, pancres etc.
B. Endocrine glands are ductless glands i.e.,
they release their secretions directly into the
bloodstream.
C. Tight junctions are cell junctions located at
the apical surface of the adjacent epithelial
cells. They prevent substances from leaking
across the surrounding tissues.
D. Adhering junctions cement the neighbouring
cells to keep them intact.
36. (b)
NCERT figure 7.7
The given figures A, B and C are skeletal muscle,
smooth muscle and cardiac muscle respectively.
Skeletal muscle fibres occur in muscles which are
attached to the skeleton. They are striated in
appearance and are under voluntary control. Smooth
muscle fibres are located in walls of hollow visceral
organs, except the heart, appear spindle-shaped, and
are also under involuntary control. Cardiac muscle
cells are located in the walls of the heart, appear
striated, and are under involuntary control.
37. (b)
Neurons forms the structural and functional unit
of nervous tissue. They are excitable cells. While
the neuroglial cells constitute the rest of the neural
system that protect and support neurons and are
non-excitable.
38. (d)
Each neuron has an enlarged portion, the cell body
(perikaryon), containing the nucleus and from the
cell body extend several processes (dendrites)
through which impulses enter from their branches.
39. (c)
They are commonly found in ducts of glands and
tubular parts of nephrons in kidneys.
40. (d)
Compound Epithelium consists of more than one
layer of cells. Only the cells of the deepest layer
rest on the basement membrane. Being multi-
layered, compound epithelia have little role in
secretion or absorption, but they provide protection
to underlying tissues against mechanical,
chemical, thermal or osmotic stresses. Compound
epithelia may be stratified or transitional.
Page 4


Solution
1. (c)
The head is triangular in shape which lies
anteriorly at right angles to the longitudinal body
axis. The head is formed by the fusion of six
segments. The flexible neck facilitates movement
in all directions.
2. (b)
The development of cockroach is
paurometabolous meaning that their development
is through nymphal stage. The nymphs look very
much like adults. The nymph grows by moulting
about 13 times to reach adult form. The last
nymphal stage has wingpads while adult
cockroaches have wings.
3. (c)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of dense regular connective tissues
in which collagen fibres are present in rows
between many parallel bundles of fibres.
4. (b)
Muscle tissue plays the vital role of providing
movement and heat generation to the organs of
the body. Muscle cells are specialized for
contractility and electrical conductivity.
5. (d)
In all connective tissue except blood (a fluid
connective tissue), the cells secrete fibres of
structural proteins called collagen or elastin.
6. (b)
A neuron (also known as a neurone or nerve
cell) is an electrically excitable cell that
processes and transmits information through
electrical and chemical signals. These signals
between neurons occur via synapses, specialized
connections with other cells. A typical neuron
possesses a cell body (soma), dendrites, and an
axon.
7. (d)
Cartilage is a type of connective tissue which is
present in human external ears, the nose tip,
ribcage joints, etc.
8. (d)
Cells of smooth muscle tissue are spindle shaped
and pointed at their ends. Striations are absent
due to different arrangement of actin and myosin
filaments. Smooth muscle is the earliest form of
muscle to evolve.
9. (a)
Cardiac muscles are involuntary, cross striated
& non-fatigued fibres. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its
neighbouring cells are also stimulated to contract.
10. (d)
Smooth muscle is an involuntary, spindle shaped,
uninucleated, tapering and non-striated muscle. Smooth
muscle is responsible for the contractility of hollow
organs, such as blood vessels, the gastrointestinal tract,
the bladder, or the uterus. Its structure differs greatly
from that of skeletal muscle, although it can develop
isometric force per cross sectional area which is equal
to that of skeletal muscle.
11. (c)
Loose connective tissue has cells and fibres loosely
arranged in a semi-fluid ground substance, for example,
areolar tissue present beneath the skin. It serves as a
support framework and specialised to store fats.
12. (d)
NCERT figure 7.18
Label 3 and 4 are respectively genital chamber and
vestibulum which is collectively called genital pouch.
13. (b)
(II) Products of exorine glands are released
through ducts or tubes.
14. (b)
On the basis of the mode of pouring of secretion, gland
are divided into – (a) exocrine, and (b) endocrine glands.
Exocrine glands secrete mucus, saliva, oil, digestive
enzymes and other cell products. These products
are released through ducts or tubes. In contrast,
endocrine glands do not have ducts. Their products
called hormones are secreted directly into the fluid
bathing the gland.
15. (d)
NCERT figure 7.7(a)
Locomotion (performed by limbs) in humans depends
on the movements of muscle fibres. Skeletal muscles
are attached to the bones by tendons and help in the
movement of the parts of skeleton. These muscles
are under the control of conscious mind and are called
voluntary muscles. Under the microscope, these
muscles show transverse stripes and hence are
designated as striated muscles.
16. (d)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
17. (d)
Squamous epithelium is formed of thin discoidal
and polygonal cells that fit like tiles in a floor, so
is also called pavement epithelium. It is found in
the walls of blood vessels, in the alveoli of lung
for exchange of gases, and in Bowman’s capsule
of nephron for ultra filtration.
18. (c)
Mast cell are a cell found in connective tissue that
contains numerous basophilic granules and release
substances such as heparin and histamine in
response to injury or inflammation of tissues.
19. (a)
There are three ganglia lie in the thorax, and six
in the abdomen. Each eye consists of about 2000
hexagonal ommatidia.
20. (c)
Keratinised squamous:- This epithelium occurs
in the epidermis of the skin of land vertebrates.
Squamous epithelium:- This epithelium is present
in the terminal bronchioles, blood vessels, alveoli
of the lungs, etc.
Columnar epithelium:- This epithelium lines the
stomach, inner surface of the gall bladder, intestine
and bile duct. It has a secretory role and is called
glandular epithelium.
Ciliated epithelium:- This epithelium lines most of
the respiratory tract and Fallopian tubes
(oviducts). These cells comprise columnar cells
which have cilia on the free surface.
Cuboidal epithelium:- Is present in small salivary
and pancreatic duct. These cells of cuboidal
epithelium are cubical and more or less squarish
in shape.
21. (d)
Basement membrane is a thin extracellular
supporting layer that separates a layer of epithelial
cells from the underlying lamina propria and is
composed of the basal lamina and reticular lamina
22. (a)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
23. (c)
Gland is an organ in the human or animal body
which secretes particular chemical substances for
use in the body or for discharge into the
surroundings.
24. (d)
Plasmodesmata are narrow channels that act as
intercellular cytoplasmic bridges to facilitate
communication and transport of materials
between plant cells. Adhering, tight and gap
junctions are specialized junctions that provide both
structural and functional links between the
individual cells of animal tissues.
25. (a)
Intestine is lined by glandular epithelium which is
secretory in function. The glands found in
intestine are exocrine and may be unicellular or
multicellular. When unicellular glands secrete
mucus, they are called mucous cells or goblet cells
and are common in the columnar epithelium of
intestine. When unicellular glands secrete a clear
watery fluid, they are called serous cells which
are also present in intestinal glands. On the other
hand, multicellular glands consist of a duct and
secretory portion, both formed of epithelial cells.
They are further of two types: tubular and
saccular. In tubular glands secretory portion is
tube like, for example, Crypts of Lieberkuhn (a
type of simple straight tubular glands found in
intestine) and Brunner’s gland (a type of simple
branched tubular glands found in intestine).
26. (a)
Both statements are correct.
27. (c)
All connective tissue is derived from mesoderm,
the middle germ cell layer in the embryo.
Connective tissue is made up of fibers forming a
framework and support structure for body tissues
and organs.
28. (d)
All connective tissue consists of three main
components: fibres (elastic and collagenous
fibres), ground substance and cells. But blood and
lymph lack the fibre component.
29. (b)
Females lack a pair of short, thread-like anal
styles that males have. The male cockroach's
anal/caudal styles emerge from the 9th abdominal
segment.
30. (c)
i. Tight junctions: These junctions are formed
by adjacent epithelial cells which are tightly
packed together. These junctions help
prevent substances from leaking across the
tissue.
ii. Gap junctions: These junctions are formed
by connecting the cytoplasm of adjoining
cells. This facilitate cells to communicate with
each other.
iii. Adherens junctions: These junctions cement
the adjacent cells together. They serve
anchoring function.
31. (a)
Squamous epithelium is an epithelium whose
most superficial layer consists of flat, scale-like
cells called squamous epithelial cells. The
epithelium may be composed of one layer of
these cells, in which it is referred to as simple
squamous epithelium or it may possess multiple
layers, referred to as stratified squamous
epithelium.
32. (b)
Connective tissue is a group of tissues in the body
that maintains the form of the body and its organs
and provides cohesion and internal support. The
connective tissues include several types of fibrous
tissue that vary only in their density and cellularity,
as well as the more specialized and recognizable
variants-bone, ligaments, tendons, cartilage, and
adipose (fat) tissue.
33. (b)
All the given statements are associated with
bone. Bone is a rigid body tissue consisting of
cells embedded in an abundant, hard
intercellular material. This material consists of
two important components - collagen and
calcium phosphate. It forms the major portion
of the human skeleton. Bone support and
protect the various organs of the body, produce
red and white blood cells, store minerals and
also enable mobility.
34. (b)
The smooth muscle fibres are involuntary, taper
at both ends and do not show striation. The wall
of internal organs such as the blood vessels,
stomach and intestine contains this type of muscle
tissue.
35. (a)
A. Exocrine glands are ducted glands i.e., these
glands are provided with ducts to transport their
secretions. E.g., salivary glands, pancres etc.
B. Endocrine glands are ductless glands i.e.,
they release their secretions directly into the
bloodstream.
C. Tight junctions are cell junctions located at
the apical surface of the adjacent epithelial
cells. They prevent substances from leaking
across the surrounding tissues.
D. Adhering junctions cement the neighbouring
cells to keep them intact.
36. (b)
NCERT figure 7.7
The given figures A, B and C are skeletal muscle,
smooth muscle and cardiac muscle respectively.
Skeletal muscle fibres occur in muscles which are
attached to the skeleton. They are striated in
appearance and are under voluntary control. Smooth
muscle fibres are located in walls of hollow visceral
organs, except the heart, appear spindle-shaped, and
are also under involuntary control. Cardiac muscle
cells are located in the walls of the heart, appear
striated, and are under involuntary control.
37. (b)
Neurons forms the structural and functional unit
of nervous tissue. They are excitable cells. While
the neuroglial cells constitute the rest of the neural
system that protect and support neurons and are
non-excitable.
38. (d)
Each neuron has an enlarged portion, the cell body
(perikaryon), containing the nucleus and from the
cell body extend several processes (dendrites)
through which impulses enter from their branches.
39. (c)
They are commonly found in ducts of glands and
tubular parts of nephrons in kidneys.
40. (d)
Compound Epithelium consists of more than one
layer of cells. Only the cells of the deepest layer
rest on the basement membrane. Being multi-
layered, compound epithelia have little role in
secretion or absorption, but they provide protection
to underlying tissues against mechanical,
chemical, thermal or osmotic stresses. Compound
epithelia may be stratified or transitional.
41. (d)
Muscle tissue is contractile tissue grouped into
coordinated systems for greater efficiency. In
humans the muscle systems are classified by gross
appearance and location of cells. The three types
of muscles are striated (or skeletal), cardiac, and
smooth (or non-striated).
42. (d)
The cardiac muscles are involuntary in function,
meaning they can't be controlled by humans, and
they're engaged in the heart's constant rhythmic
contraction and relaxation.“Cardiomyocytes are
uninucleate (single nucleus) heart muscle cells that
are cylindrical, elongated, striated, and
branching.“If the cardiac muscles are injured, they
have no ability to regenerate.
43. (d)
Assertion : Areolar tissue is the loose connective
tissue that fills space inside organs and binds skin to
underlying muscles.
Reason : Loose connective tissue has cells and
fibres loosely arranged in a semi-fluid ground
substance, for example, areolar tissue present
beneath the skin.
44. (b)
Cardiac muscle tissue is a contractile tissue
present only in the heart. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its neighbours
are also stimulated to contract.
45. (b)
Neurons, the unit of neural system are excitable
cells while chondrocytes are cartilagenous cells.
46. (b)
47. (c)
NCERT figure 7.14
A - Pronotum; B - Mesothorax; C - Metathorax;
D - Tegmina; E - Anal cerci
48. (d)
Cockroach belongs to phylum Arthropoda and
class Insecta. It belongs to Arthropoda due to
the presence of jointed appendages and Insecta
class due to the presence of three body regions
(head, thorax and abodomen) and six legs.
49. (b)
External ear are absent in frog and only tympanum
can be seen externally
50. (b)
NCERT figure 7.15(a)
A - Ocellus; B - Compound eye; C - Mandible;
D - Maxilla; E - Labrum; F - Labium.
51. (a)
NCERT figure 7.4
The given figure shows the image of areolar
tissue, a type of loose connective tissue. Loose
connective tissue (which includes areolar tissue,
reticular tissue, and adipose tissue) is the most
common type of connective tissue in vertebrates.
It holds organs in place and attaches epithelial
tissue to other underlying tissues. It also surrounds
the blood vessels and nerves. Areolar tissues are
present beneath the skin and serve as a support
framework for epithelium. It contains fibroblast,
macrophages, collagen fibres and mast cells.
52. (b)
Epithelial tissues are thin tissues that cover all the
exposed surfaces of the body. They form the external
skin, the inner lining of the mouth, digestive tract,
secretory glands, the lining of hollow parts of every
organ such as the heart, lungs, eyes, ears, the urogenital
tract, as well as the ventricular system of the brain and
central canals of the spinal cord. The cells making up
epithelia are often closely bound to one another through
specialized structures called tight junctions. They are
also free from blood vessels and nerves and are
supported by a connective tissue called the basement
membrane. They have polarity with a distinct basal
domain facing the basement membrane and the other
apical surface facing the lumen of an organ or the external
environment.
53. (d)
NCERT figure 7.1(d) & 7.2(b)
Tissue 1 is columnar cells bearing cilia and tissue
2 is multicellular glandular epithelium.
Ciliated columnar epithelial cells possess fine
hairlike outgrowths, cilia on their free surfaces.
These cilia are capable of rapid, rhythmic,
wavelike beatings in a certain direction. This
movement of the cilia in a certain direction causes
the mucus, which is secreted by the goblet cells,
to move (flow or stream) in that direction. Ciliated
epithelium is usually found in the air passages like
the nose. It is also found in the uterus and fallopian
tubes of females. Columnar epithelium with goblet
cells is called glandular epithelium. Some parts
of the glandular epithelium consist of such a large
number of goblet cells that there are only a few
normal epithelial cells left.
Page 5


Solution
1. (c)
The head is triangular in shape which lies
anteriorly at right angles to the longitudinal body
axis. The head is formed by the fusion of six
segments. The flexible neck facilitates movement
in all directions.
2. (b)
The development of cockroach is
paurometabolous meaning that their development
is through nymphal stage. The nymphs look very
much like adults. The nymph grows by moulting
about 13 times to reach adult form. The last
nymphal stage has wingpads while adult
cockroaches have wings.
3. (c)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of dense regular connective tissues
in which collagen fibres are present in rows
between many parallel bundles of fibres.
4. (b)
Muscle tissue plays the vital role of providing
movement and heat generation to the organs of
the body. Muscle cells are specialized for
contractility and electrical conductivity.
5. (d)
In all connective tissue except blood (a fluid
connective tissue), the cells secrete fibres of
structural proteins called collagen or elastin.
6. (b)
A neuron (also known as a neurone or nerve
cell) is an electrically excitable cell that
processes and transmits information through
electrical and chemical signals. These signals
between neurons occur via synapses, specialized
connections with other cells. A typical neuron
possesses a cell body (soma), dendrites, and an
axon.
7. (d)
Cartilage is a type of connective tissue which is
present in human external ears, the nose tip,
ribcage joints, etc.
8. (d)
Cells of smooth muscle tissue are spindle shaped
and pointed at their ends. Striations are absent
due to different arrangement of actin and myosin
filaments. Smooth muscle is the earliest form of
muscle to evolve.
9. (a)
Cardiac muscles are involuntary, cross striated
& non-fatigued fibres. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its
neighbouring cells are also stimulated to contract.
10. (d)
Smooth muscle is an involuntary, spindle shaped,
uninucleated, tapering and non-striated muscle. Smooth
muscle is responsible for the contractility of hollow
organs, such as blood vessels, the gastrointestinal tract,
the bladder, or the uterus. Its structure differs greatly
from that of skeletal muscle, although it can develop
isometric force per cross sectional area which is equal
to that of skeletal muscle.
11. (c)
Loose connective tissue has cells and fibres loosely
arranged in a semi-fluid ground substance, for example,
areolar tissue present beneath the skin. It serves as a
support framework and specialised to store fats.
12. (d)
NCERT figure 7.18
Label 3 and 4 are respectively genital chamber and
vestibulum which is collectively called genital pouch.
13. (b)
(II) Products of exorine glands are released
through ducts or tubes.
14. (b)
On the basis of the mode of pouring of secretion, gland
are divided into – (a) exocrine, and (b) endocrine glands.
Exocrine glands secrete mucus, saliva, oil, digestive
enzymes and other cell products. These products
are released through ducts or tubes. In contrast,
endocrine glands do not have ducts. Their products
called hormones are secreted directly into the fluid
bathing the gland.
15. (d)
NCERT figure 7.7(a)
Locomotion (performed by limbs) in humans depends
on the movements of muscle fibres. Skeletal muscles
are attached to the bones by tendons and help in the
movement of the parts of skeleton. These muscles
are under the control of conscious mind and are called
voluntary muscles. Under the microscope, these
muscles show transverse stripes and hence are
designated as striated muscles.
16. (d)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
17. (d)
Squamous epithelium is formed of thin discoidal
and polygonal cells that fit like tiles in a floor, so
is also called pavement epithelium. It is found in
the walls of blood vessels, in the alveoli of lung
for exchange of gases, and in Bowman’s capsule
of nephron for ultra filtration.
18. (c)
Mast cell are a cell found in connective tissue that
contains numerous basophilic granules and release
substances such as heparin and histamine in
response to injury or inflammation of tissues.
19. (a)
There are three ganglia lie in the thorax, and six
in the abdomen. Each eye consists of about 2000
hexagonal ommatidia.
20. (c)
Keratinised squamous:- This epithelium occurs
in the epidermis of the skin of land vertebrates.
Squamous epithelium:- This epithelium is present
in the terminal bronchioles, blood vessels, alveoli
of the lungs, etc.
Columnar epithelium:- This epithelium lines the
stomach, inner surface of the gall bladder, intestine
and bile duct. It has a secretory role and is called
glandular epithelium.
Ciliated epithelium:- This epithelium lines most of
the respiratory tract and Fallopian tubes
(oviducts). These cells comprise columnar cells
which have cilia on the free surface.
Cuboidal epithelium:- Is present in small salivary
and pancreatic duct. These cells of cuboidal
epithelium are cubical and more or less squarish
in shape.
21. (d)
Basement membrane is a thin extracellular
supporting layer that separates a layer of epithelial
cells from the underlying lamina propria and is
composed of the basal lamina and reticular lamina
22. (a)
Tendons, which attach skeletal muscles to bones
and ligaments which attach one bone to another
are examples of this tissue.
23. (c)
Gland is an organ in the human or animal body
which secretes particular chemical substances for
use in the body or for discharge into the
surroundings.
24. (d)
Plasmodesmata are narrow channels that act as
intercellular cytoplasmic bridges to facilitate
communication and transport of materials
between plant cells. Adhering, tight and gap
junctions are specialized junctions that provide both
structural and functional links between the
individual cells of animal tissues.
25. (a)
Intestine is lined by glandular epithelium which is
secretory in function. The glands found in
intestine are exocrine and may be unicellular or
multicellular. When unicellular glands secrete
mucus, they are called mucous cells or goblet cells
and are common in the columnar epithelium of
intestine. When unicellular glands secrete a clear
watery fluid, they are called serous cells which
are also present in intestinal glands. On the other
hand, multicellular glands consist of a duct and
secretory portion, both formed of epithelial cells.
They are further of two types: tubular and
saccular. In tubular glands secretory portion is
tube like, for example, Crypts of Lieberkuhn (a
type of simple straight tubular glands found in
intestine) and Brunner’s gland (a type of simple
branched tubular glands found in intestine).
26. (a)
Both statements are correct.
27. (c)
All connective tissue is derived from mesoderm,
the middle germ cell layer in the embryo.
Connective tissue is made up of fibers forming a
framework and support structure for body tissues
and organs.
28. (d)
All connective tissue consists of three main
components: fibres (elastic and collagenous
fibres), ground substance and cells. But blood and
lymph lack the fibre component.
29. (b)
Females lack a pair of short, thread-like anal
styles that males have. The male cockroach's
anal/caudal styles emerge from the 9th abdominal
segment.
30. (c)
i. Tight junctions: These junctions are formed
by adjacent epithelial cells which are tightly
packed together. These junctions help
prevent substances from leaking across the
tissue.
ii. Gap junctions: These junctions are formed
by connecting the cytoplasm of adjoining
cells. This facilitate cells to communicate with
each other.
iii. Adherens junctions: These junctions cement
the adjacent cells together. They serve
anchoring function.
31. (a)
Squamous epithelium is an epithelium whose
most superficial layer consists of flat, scale-like
cells called squamous epithelial cells. The
epithelium may be composed of one layer of
these cells, in which it is referred to as simple
squamous epithelium or it may possess multiple
layers, referred to as stratified squamous
epithelium.
32. (b)
Connective tissue is a group of tissues in the body
that maintains the form of the body and its organs
and provides cohesion and internal support. The
connective tissues include several types of fibrous
tissue that vary only in their density and cellularity,
as well as the more specialized and recognizable
variants-bone, ligaments, tendons, cartilage, and
adipose (fat) tissue.
33. (b)
All the given statements are associated with
bone. Bone is a rigid body tissue consisting of
cells embedded in an abundant, hard
intercellular material. This material consists of
two important components - collagen and
calcium phosphate. It forms the major portion
of the human skeleton. Bone support and
protect the various organs of the body, produce
red and white blood cells, store minerals and
also enable mobility.
34. (b)
The smooth muscle fibres are involuntary, taper
at both ends and do not show striation. The wall
of internal organs such as the blood vessels,
stomach and intestine contains this type of muscle
tissue.
35. (a)
A. Exocrine glands are ducted glands i.e., these
glands are provided with ducts to transport their
secretions. E.g., salivary glands, pancres etc.
B. Endocrine glands are ductless glands i.e.,
they release their secretions directly into the
bloodstream.
C. Tight junctions are cell junctions located at
the apical surface of the adjacent epithelial
cells. They prevent substances from leaking
across the surrounding tissues.
D. Adhering junctions cement the neighbouring
cells to keep them intact.
36. (b)
NCERT figure 7.7
The given figures A, B and C are skeletal muscle,
smooth muscle and cardiac muscle respectively.
Skeletal muscle fibres occur in muscles which are
attached to the skeleton. They are striated in
appearance and are under voluntary control. Smooth
muscle fibres are located in walls of hollow visceral
organs, except the heart, appear spindle-shaped, and
are also under involuntary control. Cardiac muscle
cells are located in the walls of the heart, appear
striated, and are under involuntary control.
37. (b)
Neurons forms the structural and functional unit
of nervous tissue. They are excitable cells. While
the neuroglial cells constitute the rest of the neural
system that protect and support neurons and are
non-excitable.
38. (d)
Each neuron has an enlarged portion, the cell body
(perikaryon), containing the nucleus and from the
cell body extend several processes (dendrites)
through which impulses enter from their branches.
39. (c)
They are commonly found in ducts of glands and
tubular parts of nephrons in kidneys.
40. (d)
Compound Epithelium consists of more than one
layer of cells. Only the cells of the deepest layer
rest on the basement membrane. Being multi-
layered, compound epithelia have little role in
secretion or absorption, but they provide protection
to underlying tissues against mechanical,
chemical, thermal or osmotic stresses. Compound
epithelia may be stratified or transitional.
41. (d)
Muscle tissue is contractile tissue grouped into
coordinated systems for greater efficiency. In
humans the muscle systems are classified by gross
appearance and location of cells. The three types
of muscles are striated (or skeletal), cardiac, and
smooth (or non-striated).
42. (d)
The cardiac muscles are involuntary in function,
meaning they can't be controlled by humans, and
they're engaged in the heart's constant rhythmic
contraction and relaxation.“Cardiomyocytes are
uninucleate (single nucleus) heart muscle cells that
are cylindrical, elongated, striated, and
branching.“If the cardiac muscles are injured, they
have no ability to regenerate.
43. (d)
Assertion : Areolar tissue is the loose connective
tissue that fills space inside organs and binds skin to
underlying muscles.
Reason : Loose connective tissue has cells and
fibres loosely arranged in a semi-fluid ground
substance, for example, areolar tissue present
beneath the skin.
44. (b)
Cardiac muscle tissue is a contractile tissue
present only in the heart. Cell junctions fuse the
plasma membranes of cardiac muscle cells and
make them stick together. Communication
junctions (intercalated discs) at some fusion points
allow the cells to contract as a unit, i.e., when
one cell receives a signal to contract, its neighbours
are also stimulated to contract.
45. (b)
Neurons, the unit of neural system are excitable
cells while chondrocytes are cartilagenous cells.
46. (b)
47. (c)
NCERT figure 7.14
A - Pronotum; B - Mesothorax; C - Metathorax;
D - Tegmina; E - Anal cerci
48. (d)
Cockroach belongs to phylum Arthropoda and
class Insecta. It belongs to Arthropoda due to
the presence of jointed appendages and Insecta
class due to the presence of three body regions
(head, thorax and abodomen) and six legs.
49. (b)
External ear are absent in frog and only tympanum
can be seen externally
50. (b)
NCERT figure 7.15(a)
A - Ocellus; B - Compound eye; C - Mandible;
D - Maxilla; E - Labrum; F - Labium.
51. (a)
NCERT figure 7.4
The given figure shows the image of areolar
tissue, a type of loose connective tissue. Loose
connective tissue (which includes areolar tissue,
reticular tissue, and adipose tissue) is the most
common type of connective tissue in vertebrates.
It holds organs in place and attaches epithelial
tissue to other underlying tissues. It also surrounds
the blood vessels and nerves. Areolar tissues are
present beneath the skin and serve as a support
framework for epithelium. It contains fibroblast,
macrophages, collagen fibres and mast cells.
52. (b)
Epithelial tissues are thin tissues that cover all the
exposed surfaces of the body. They form the external
skin, the inner lining of the mouth, digestive tract,
secretory glands, the lining of hollow parts of every
organ such as the heart, lungs, eyes, ears, the urogenital
tract, as well as the ventricular system of the brain and
central canals of the spinal cord. The cells making up
epithelia are often closely bound to one another through
specialized structures called tight junctions. They are
also free from blood vessels and nerves and are
supported by a connective tissue called the basement
membrane. They have polarity with a distinct basal
domain facing the basement membrane and the other
apical surface facing the lumen of an organ or the external
environment.
53. (d)
NCERT figure 7.1(d) & 7.2(b)
Tissue 1 is columnar cells bearing cilia and tissue
2 is multicellular glandular epithelium.
Ciliated columnar epithelial cells possess fine
hairlike outgrowths, cilia on their free surfaces.
These cilia are capable of rapid, rhythmic,
wavelike beatings in a certain direction. This
movement of the cilia in a certain direction causes
the mucus, which is secreted by the goblet cells,
to move (flow or stream) in that direction. Ciliated
epithelium is usually found in the air passages like
the nose. It is also found in the uterus and fallopian
tubes of females. Columnar epithelium with goblet
cells is called glandular epithelium. Some parts
of the glandular epithelium consist of such a large
number of goblet cells that there are only a few
normal epithelial cells left.
54. (d)
Without respiration, no animal can survive.
Cockroach is not as simple as Hydra where oxygen
can diffuse directly into the cells. There is a system
of tubes in cockroach, the tracheal system, with
the help of which oxygen goes directly into the
tissues by intracellular capillary system.
55. (c)
Epithelial tissue covers the body surface, or lines
the body cavity. The cells rest upon a non-cellular
basement membrane which is secreted by epithelial
cells. It is not nourished by blood, so nonvascularized.
56. (d)
Most cells in animal tissues (with the exception
of a few terminally differentiated cells such as
skeletal muscle cells and blood cells) are in
communication with their adjoining cells via gap
junctions. At the place where gap junction is
present, membranes of two adjacent cells are
separated by a uniform narrow gap of about 2-4
nm. The gap is spanned by channel forming
proteins called connexins, which allow inorganic
ions and other small water soluble molecules to
pass directly from cytoplasm of one cell to
cytoplasm of other cell.
57. (b)
Bone marrow is the flexible tissue in the interior
of bones. In humans, red blood cells are produced
by cores of bone marrow in the heads of long
bones in a process known as haematopoiesis.
Bone marrow is also a key component of the
lymphatic system, producing the lymphocytes that
support the body's immune system.
58. (c)
Chondrocytes are the only cells found in
cartilage. They produce and maintain the
cartilaginous matrix, which consists mainly of
collagen and proteoglycans. The chondrocytes
lie between the muscle fibres. It is found in the
epiglottis (part of the larynx) and the pinnae (the
external ear flaps of many mammals including
humans).
59. (c)
Anal style is a pair of short, thread-like structure
present in males only. In both sexes, the 10th
segment bears of pair of jointed filamentous
structures called anal cerci.
60. (c)
In cockroach, respiratory system consists of a
network of trachea, that open through 10 pairs of
small holes called spiracles present on the lateral
side of the body.
61. (c)
Cockroaches absorb nitrogenous waste products and
convert them into uric acid which is excreted out-
through hindgut. Hence they called as uricotelic.
62. (d)
Cartilage is a soft skeletal tissue (a specialized
connective tissue) which forms the endoskeleton
of the vertebrates. It is a vascular and nutrient
are diffused through the matrix.
63. (c)
Crop is the part of foregut which is used for
storing of food.
64. (a)
On the basis of structural modification of the cells,
simple epithelium is divided into three types -
squamous, cuboidal and columnar. The squamous
epithelium is made of a single thin layer of flattened
cells with irregular boundaries. They are found
in the walls of blood vessels and air sacs of lungs.
Due to their single thin layer, they are involved in
a functions like forming a diffusion boundary.
65. (c)
Cartilage is a non-vascular type of specialised
connective tissue that is found throughout the
body.
66. (a)
A. Aquatic respiratory organ - Skin
B. Organ which acts as - Ureter
urogenital duct and
opens into the cloaca
C. A small median chamber - Cloaca
that is used to pass
faecal matter, urine and
sperms to the exterior
D. A triangular structure - Sinus
which joins the right venosus
atrium and receives
blood through vena cava
67. (b)
If the head of cockroach is cut off, it will still
alive for as long as one week, because the head
holds a bit of a nervous system while the rest is
situated along the ventral part of the body.