Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Chapter 3
Life Processes-Movement In Animals And Plants
Movement is one of the significant features of living being
Streaming of protoplasm in unicellular organism like Amoeba is simple form of
movement.
Some of movement results in change of place or Location known as locomotion
Ex. walking, running, climbing, swimming
Locomotion is generally for search of food, shelter, and mate suitable breeding grounds
favourable climatic condition or to escape from enemies/predators.
Type of Movement
Amoeboid Ex. Macrophage
Cilliary Ex. Trachea
Muscular movement Ex. Movement of our limb tongue
Contractive property of muscles is effectively used for Locomotion.
MUSCLE Muscle is specialized tissue of Mesodermal origin 40-50 body wt. contribute
by muscles.
They have special properties like excitability contractibility extensibility and elasticity.
Muscles are classified boredom their location.
i) skeletal
ii) Visceral
iii) Cardiac
Skelton muscles are closely associated with Skeletal component of body.
They have striped appearance under microscope and hence called striated muscles.
As their activities under voluntary control of nervous system they are known as
voluntary muscles.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Visceral muscles
Located in inner wall of hollow visceral organ of body like alimentary canal reproductive
tract.
They do not exhibit striation and are in smooth in appearance.
They are also known as smooth muscle/involuntary muscles
They assist transportation of food through the digestive tract and gametes through
genital tract.
Cardiac muscles
Muscle of heart many cardiac muscle cells assemble in branding pattern to form a
cardiac muscle.
They are striated involuntary in nature as the nervous system does not control their
activity directly.
Each muscle in out body made up of number of muscle bundle/fascicles held together
by a common collagenous connective tissue layer called fascia.
Each muscle bundle contains number of muscle fibers.
Each muscle fiber in lined by plasma membrane called sarcolemma enclosing
sarcoplasm.
Muscle fiber is syncitium as the sarcoplasm contains many nuclei.
Endoplasmic reticulum/ sarcoplasmic reticulum is house of +.
Muscle fiber show parallel arranged filament in the sarcoplasm called myofibrils.
Each myofibril has alternate dark and light Band on it
Striated appearance is due to distribution pattern of two proteins
Actin (light bank/I band)
Myosin (dark Band/ A band Anisotropic
Both protein arranged parallel in longitudinal axis of fiber.
Actin filament is thinner than myosin filament called thin filament.
In the centre of I bank is an elastic fiber called Z line which bisects it.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
A Bank also held together in middle of this band by thin fibrous membrane called M line.
Two successive Z line is considered as function unit of contraction know as sarcomere.
In resting phase the edge of thick filament partially overlapped by thin filament.
Structure of contractile protein
Each Actin (thin) filament is made up of two F (filamentous) actin helically wound so
each other.
Each filament is polymer of monomeric globular G actin.
Two filament of another protein tropomyosin runs close to E actin throughout its length.
A complex protein troponin is distributed at regular interval on tropomyosin.
On resting phase troponin marks the active site for kindling of myosin on the actin
filament.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Mechanisms of muscle contraction
Muscle contraction is best explained by sliding filament theory which states that
contraction of Muscle Fiber Lake place by sliding of thin filament over thick filaments.
Muscle contraction initiated by signal sent by C.N.S. via motor neurons.
Motor neurons along with muscle fiber connected so it constitutes a motor unit.
A junction between motor neuron and sarcolemma
of muscle fiber called as
neuromuscular junction/motor end plate (NMJ)
A neural signal reaching this junction releases a neuron transmitter (acetylecholin)
which generates a action potential in sarcolemma.
This spread through muscle fiber cause release of caciumlons (+2 ) in to sarcoplasm.
Increase +2 level binds +2 with submit of troponin on actin filament & thereby
remove masking of active site for myosin.
Utilization of energy from ATP hydrolysis. The myosin head now kinds to exposed active
sites on actin to form cross bridge.
This pulls the attached actin filaments toward the centre of A band.
The Z line attached to this actin is also pulls in ward thereby causing shortening of
sarcomere
The myosin releasing ADP and1 goes back to its relaxed state A new ATP bind and cross
bridge is broken.
ATP is again hydrolyzed by myosin head and cycle of cross bridge formation and
breakage repeated causing sliding.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
The process continues tell +2 are primped in to sarcoplasmic cisternal resulting
in marking of actin filament.
This cause the return of Z lines back to their original position relaxation.
Repeated activation of muscle fiber can lead to accumulation of lactic acid due to
anaerobic break down of glycogen causing fatigue.
Myosin contain red coloured pigment myoglobin which causing red colour of these
muscles.
Such muscles are called red fiber.
These muscles contain plenty of mitochondria which utilize large amount of oxygen
stored in them for ATP production also known as aerobic muscles.
Some muscle has less amount of myoglobin called white fiber. These muscles have more
number of reticulum.
They depend upon anaerobic process for energy.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Skeletal system
Skeletal system consist of a frame work of bone few cartilages.
This system significant role in movement Ex chewing food
In human 206 bone few cartilages.
Skeletal system
Axial Skeletal
Appendicular skeletal
Axial Skelton 8-0 distributed along the main axis of body
1)
Skull
(2) Vertebral column
(3) Sternums and ribs
(1)
Skull Composed of two set of bonesCranial
Facial.
Those total 22 bones
(2) Cranial bone 8 in numbers they form protective outer covering of brain.
(3) Facial region is made of 14 Skelton content which form the front part of the skull
A single U shaped hyoid bone present at the base of buccal cavity also include in skull.
Each middle ear consist their tiny bones (mallous Incus stapes) Ear onsides
Vertebral column formed by 26 serially arranged units called vertebrae.
First vertebra is atlas it articulates occipital condoyle of skull.
Vertebral column differentiate as cervical 7 Thoracic 12 Lumbar 5 Sacral 1
Fused coccygeal 1 fused.
The vertebral column protects spinal cord support head and serves attachment of
rib
and musculature of back.
There are 12 pair of ribs each rib is thin flat bone connected dorsally to vertebral column
ventrally sternum it has two articulation surface on its dorsal end of and hence
bicephalic . First 7 ribs are true ribs 8,9,10 pair of ribs do not
articulate
called
directly
with sternum but join 7 rib with help of hyaline cartilage
These are called vertebrochondral (false rib) last 2 pairs which not connected
ventrally and therefore called floating ribs
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Appendicular system The Bone of limbs with girdle known as appendicular system.
Each limb made of 30 bones.
In Hand-Bones Humerus radius ulna carpel (8 in no. wrist bones) metacarpal.
Palm bones (5 in no) phalanges (14 in no).
In leg femur, tibia fibula tarsal (7) metatarsal (5 in no) phalanges digits (14).
Pectoral & pelvic girdle bone helps in articulation of upper and town limb respectively to
axial system.
Each girdle formed by 2 bone clavicle and scapula is large triangular bone situated in the
dorsal part of thorax between 2nd to 7th ribs.
A slightly elevated ridge acromion articulates with clavicle
Below the acromion called as glenoid cavity where head of humerus articulate.
Pelvic girdle consist of two coxal bones each coxal bone formed by fusion of three bone
ilium, ischium, pubis.
AT the point of fusion of above bones is cavity acetabulum articulate with head of
femur.
Two halves of pelvic girdle meets ventrally to form pubic syphilis certainly fibrous
cartilage.
Joints
Joints are essential all type of movement involving bony party of body. Force generated
by muscle is used to carry out movement through joint where joint act as fulcrum.
Joint are classified into 3 major structural forms
Fibrous Ex. Flat bone of skull.
Cartilaginous - Adjacent vertical lateral.
Synovial Ex. knee joint.
Fibrous Joint not allow any movement.
Flat skull bone which fuse end to end with help of dense fibrous connective tissue in
suture of skull.
Cartilaginous Joint Permit limited movement bone joined with help of cartilage.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Synovial Joint Presence of fluid filled cavity between articulating surface such allow
considerable movement Ball and socket Humerus and pectoral girdle,
pivot
joint
(between the atlas and axis)
Hinge Joint knee joint.
Gliding joint: between the carpals
Exercise
Q.1
Name the longest bone of the body?
Ans.
Femur
Q.2
What type of the muscles form the heart?
Ans.
Cardiac
Q.3
Contraction of muscle requires energy. What is the source of energy?
Ans.
Contraction requires energy & it is supplied by food. Glucose from the food is carried in
the blood to the muscles where it is stored in the form of glycogens. This glycogen forms
a store of potential energy for muscles contraction.
Q.4
What are gliding movements & rotatory movements?
Ans.
Gliding movements. When one bone or its parts slides over another rotatory
movements moving a limb round in a circular way This is possible at the shoulder & hip.
Q.5
What is difference between pelvis of male & female?
Ans.
The pelvis of male & female differ considerably. The female pelvis is wider & shallower
than that of male. The structural adaptation is associated with pregnancy & parturition.
Q.6
Describe the various types of joints?
Ans.
Joints are essential all type of movement involving bony party of body. Force generated
by muscle is used to carry out movement through joint where joint act as fulcrum.
Joint are classified into 3 major structural forms
Fibrous Ex. Flat bone of skull.
Cartilaginous - Adjacent vertical lateral.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Synovial Ex. knee joint.
Fibrous Joint not allow any movement.
Flat skull bone which fuse end to end with help of dense fibrous connective tissue in
suture of skull.
Cartilaginous Joint Permit limited movement bone joined with help of cartilage.
Synovial Joint Presence of fluid filled cavity between articulating surface such allow
considerable movement Ball and socket Humerus and pectoral girdle, pivot joint
(between the atlas and axis)
Hinge Joint knee joint.
Gliding joint: between the carpals
Q.7
Describe the mechanism of muscle contraction?
Ans.
Mechanisms of muscle contraction Muscle contraction is best explained by sliding
filament theory which states that contraction of Muscle Fiber Lake place by sliding of
thin filament over thick filaments.
Muscle contraction initiated by signal sent by C.N.S. via motor neurons.
Motor neurons along with muscle fiber connected so it constitutes a motor unit.
A junction between motor neuron and sarcolemma
of muscle fiber called as
neuromuscular junction/motor end plate (NMJ)
A neural signal reaching this junction releases a neuron transmitter (acetyle cholin)
which generates a action potential in sarcolemma.
This spread through muscle fiber cause release of calcium ions (+2 ) in to sarcoplasm.
Increase +2 level binds +2 with submit of troponin on actin filament & thereby
remove masking of active site for myosin.
Utilization of energy from ATP hydrolysis. The myosin head now kinds to exposed active
sites on actin to form cross bridge.
This pulls the attached actin filaments toward the centre of A band.
The Z line attached to this actin is also pulls in ward thereby causing shortening of
sarcomere
Copyright 2013 GenextStudents Limited. All Rights Reserved
Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
The myosin releasing ADP and 1 goes back to its relaxed state A new ATP bind and
cross bridge is broken.
ATP is again hydrolyzed by myosin head and cycle of cross bridge formation and
breakage repeated causing sliding.
The process continues tell +2 are primped in to sarcoplasmic cisternal resulting
in marking of actin filament.
This cause the return of Z lines back to their original position relaxation.
Repeated activation of muscle fiber can lead to accumulation of lactic acid due to
anaerobic break down of glycogen causing fatigue.
Myosin contain red coloured pigment myoglobin which causing red colour of these
muscles.
Such muscles are called red fiber.
These muscles contain plenty of mitochondria which utilize large amount of oxygen
stored in them for ATP production also known as aerobic muscles.
Some muscle has less amount of myoglobin called white fiber. These muscles have more
number of reticulum.
They depend upon anaerobic process for energy.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Q.8
What is Clavicle?
Ans.
Clavicle is also called as collar bone. It is a curved bone. It is attached to upper end of
sternum.
Q.9
Write the functions of girdles.
Ans.
The girdles attach the arms & legs to the axial skeleton.
The pelvic girdle supports the abdominal contents & transmits the weight of the body to
the legs.
Girdles aid in movements of limbs.
Q.10
Describe the skeletal system?
Ans.
Skeletal system
Axial Skeletal
Appendicular skeletal
Axial Skelton 8-0 distributed along the main axis of body
1) Skull
(2) Vertebral column
(1) Skull Composed of two set of bones
(3) Sternums and ribs
Cranial
Facial.
Those total 22 bones
(2) Cranial bone 8 in numbers they form protective outer covering of brain.
(3) Facial region is made of 14 Skelton content which form the front part of the skull
A single U shaped hyoid bone present at the base of buccal cavity also include in skull.
Each middle ear consist their tiny bones (mallous Incus stapes) Ear onsides
Vertebral column formed by 26 serially arranged units called vertebrae.
First vertebra is atlas it articulates occipital condoyle of skull.
Vertebral column differentiate as cervical 7 Thoracic 12 Lumbar 5 Sacral 1
Fused
coccygeal 1 fused.
The vertebral column protects spinal cord support head and serves attachment
of
and musculature of back.
There are 12 pair of ribs each rib is thin flat bone connected dorsally to vertebral
column ventrally sternum it has two articulation surface on its dorsal end of and hence
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11
rib
Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
called bicephalic . First 7 ribs are true ribs 8,9,10 pair of ribs do not
articulate directly
with sternum but join 7 rib with help of hyaline cartilage
These are called vertebrochondral (false rib) last 2 pairs which not connected ventrally and
therefore called floating ribs
Appendicular system The Bone of limbs with girdle known as appendicular system. Each
limb made of 30 bones.
In Hand-Bones Humerus radius ulna carpel (8 in no. wrist bones) metacarpal.
Palm bones (5 in no) phalanges (14 in no).
In leg femur, tibia fibula tarsal (7) metatarsal (5 in no) phalanges digits (14)
Pectoral & pelvic girdle bone helps in articulation of upper and town limb respectively to
axial system.
Each girdle formed by 2 bone clavicle and scapula is large triangular bone situated in the
dorsal part of thorax between 2nd to 7th ribs.
A slightly elevated ridge acromion articulates with clavicle
Below the acromion called as glenoid cavity where head of humerus wliculate.
Pelvic girdle consist of two coxal bones each coxal bone formed by fusion of three bone
ilium, ischium, pubis.
AT the point of fusion of above bones is cavity a cetabulum articulate with head of femur.
Two halves of pelvic girdle meets ventrally to form pubic syphilis certainly fibrous cartilage.
Q.11
What is the spinal curvature?
Ans.
When a child is born its vertebral column is practically straight. As the child grows the
vertebral column starts showing certain curves which become predominant in a full
grown adult. Two forward & two backward curves can be seen in the adult. The forward
curves are termed as thoracic & lumber curves while the backward curves are thoracic &
sacral. These curves help to have normal posture & also help as shock absorbers.
Q.12
Write brief account on structure of contractile protein?
Ans.
Structure of contractile protein
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Each Actin (thin) filament is made up of two F (filamentous) actin helically wound so
each other.
Each filament is polymer of monomeric globular G actin.
Two filament of another protein tropomyosin runs close to E actin throughout its length.
A complex protein troponin is distributed at regular interval on tropomyosin.
On resting phase troponin marks the active site for kindling of myosin on the actin
filament.
Q.13
Distinguish between bone & cartilage?
Ans.
Bone is a calcified connective tissue with osteoplast, lacunae & Haversian system
whereas cartilage is a specialized conductive tissue devoid of mineral matter & contains
elastic matrix & chondroblasts.
Q.14
Skull bones are flat & made up of different pieces. Why?
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Ans.
The flat & curved bones with sutured joints form the cranial cavity for lodging &
protecting the brain. Injury to one part or the bone of the skull will not break the whole
skull.
Q.15
Describe the muscle types?
Ans.
Muscle Muscle is specialized tissue of Meso dermal origin 40-50 body wt. contribute
by muscles.
They have special properties like excitability contractibility extensibility and elasticity.
Muscles are classified boredom their location.
i) skeletal
ii) Visceral
iii) Cardiac
Skelton muscles are closely associated with Skeletal component of body.
They have striped appearance under microscope and hence called striated muscles.
As their activities under voluntary control of nervous system they are known as
voluntary muscles.
Visceral muscles Located in inner wall of hollow visceral organ of body like alimentary
canal reproductive tract.
They do not exhibit striation and are in smooth in appearance.
They are also known as smooth muscle/involuntary muscles
They assist transportation of food through the digestive tract and gametes through
genital tract.
Cardiac muscles Muscle of heart many cardiac muscle cells assemble in branding
pattern to form a cardiac muscle.
They are striated involuntary in nature as the nervous system does not control their
activity directly.
Each muscle in out body made up of number of muscle bundle/fascicles held together
by a common collagenous connective tissue layer called fascia.
Each muscle bundle contains number of muscle fibers.
Each muscle fiber in lined by plasma membrane called sarcolemma enclosing
sarcoplasm.
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Class 7-Science-Biology-Chapter3-Life Processes-Movement In Animals And Plants
Muscle fiber is syncitium as the sarcoplasm contains many nuclei.
Endoplasmic reticulum/ sarcoplasmic reticulum is house of +.
Muscle fiber show parallel arranged filament in the sarcoplasm called myofibrils.
Each myofibril has alternate dark and light Band on it
Striated appearance is due to distribution pattern of two proteins
Actin (light bank/I band)
Myosin (dark Band/ A band Anisotropic
Both protein arranged parallel in longitudinal axis of fiber.
Actin filament is thinner than myosin filament called thin filament.
In the centre of I bank is an elastic fiber called Z line which bisects it.
A Bank also held together in middle of this band by thin fibrous membrane called M line.
Two successive Z line is considered as function unit of contraction know as sarcomere.
In resting phase the edge of thick filament partially overlapped by thin filament.
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15
