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All questions of Structural Organisation in Animals for NEET Exam
Mineral found in red pigment of vertebrate blood is[1989]- a)magnesium
- b)iron
- c)calcium
- d)copper
Correct answer is option 'B'. Can you explain this answer?
Mineral found in red pigment of vertebrate blood is
[1989]
a)
magnesium
b)
iron
c)
calcium
d)
copper
|
Pooja Mehta answered |
Red pigment of vertebrate blood is haemoglobin. Haemoglobin is a conjugated protein. It consists of a basic protein globin joined to a nonprotein group heme, hence the name haemoglobin. Heme is an iron-porphyrin ring. A mammalian haemoglobin molecule is a complex of 4 heme molecules joined with 4 globin molecules.
Lymph differs from blood in possessing[1989]- a)only WBC
- b)more RBC and WBC
- c)more RBC and few WBC
- d)more WBC and few RBC
Correct answer is option 'A'. Can you explain this answer?
Lymph differs from blood in possessing
[1989]
a)
only WBC
b)
more RBC and WBC
c)
more RBC and few WBC
d)
more WBC and few RBC
|
Ashish Tiwary answered |
Lymph differs from blood in possessing WBCs [and lacking in RBCs].
Which of the following is not exclusively supplied with involuntary muscles ?[1998]- a)Muscular coats of blood vessels
- b)Muscles of the ducts of glands
- c)Muscles of iris
- d)Muscles of urethra
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not exclusively supplied with involuntary muscles ?
[1998]
a)
Muscular coats of blood vessels
b)
Muscles of the ducts of glands
c)
Muscles of iris
d)
Muscles of urethra
|
Arnab Iyer answered |
Voluntary muscles - under control of our will. Involuntary muscles - Not under control of our will. Muscles of urethra also remain under voluntary control after infancy.
Epithelial tissue with thin flat cells appearing like packed tiles occurs on[1994]- a)inner lining of cheek
- b)inner lining of stomach
- c)inner lining of fallopian tubes
- d)inner lining of ovary
Correct answer is option 'A'. Can you explain this answer?
Epithelial tissue with thin flat cells appearing like packed tiles occurs on
[1994]
a)
inner lining of cheek
b)
inner lining of stomach
c)
inner lining of fallopian tubes
d)
inner lining of ovary
|
|
Arnab Iyer answered |
Squamous epithelial cells have the appearance of thin, flat plates. The shape of the nucleus usually corresponds to the cell form and help to identify the type of epithelium. Squamous cells, for example, tend to have horizontal flattened, elliptical nuclei because of the thin flattened form of the cell. They form the lining of cavities such as the mouth, blood vessels, heart and lungs and make up the outer layers of the skin.
Stratum germinativum is an example of which kind of epithelium?[1997]- a)Cuboidal
- b)Ciliated
- c)Columnar
- d)Squamous
Correct answer is option 'C'. Can you explain this answer?
Stratum germinativum is an example of which kind of epithelium?
[1997]
a)
Cuboidal
b)
Ciliated
c)
Columnar
d)
Squamous
|
Supriya Senapati answered |
Stratum Germinativum is an example of columnar epithelium.
The inner most layer is called stratum germinativum has columnar cells resting upon a common basement membrane.
The inner most layer is called stratum germinativum has columnar cells resting upon a common basement membrane.
During an injury nasal septum gets damaged and for its recovery which cartilage is preferred?[2001]- a)Hyaline cartilage
- b)Elastic cartilage
- c)Calcified cartilage
- d)Fibrous cartilage
Correct answer is option 'A'. Can you explain this answer?
During an injury nasal septum gets damaged and for its recovery which cartilage is preferred?
[2001]
a)
Hyaline cartilage
b)
Elastic cartilage
c)
Calcified cartilage
d)
Fibrous cartilage
|
Muskaan Basak answered |
Hyaline cartilage is firm but slightly elastic with clear matrix. It is present in larynx, trachea, bronchi, nose. Elastic cartilage occur in external ear. Calcified cartilage occurs in suprascapula. Fibrous cartilage occurs in intervertebral discs.
Basement membrane is made up of[1997]- a)epidermal cells only
- b)endodermal cells only
- c)both epidermal and endodermal cells
- d)no cell at all, but is a product of epithelial cells
Correct answer is option 'D'. Can you explain this answer?
Basement membrane is made up of
[1997]
a)
epidermal cells only
b)
endodermal cells only
c)
both epidermal and endodermal cells
d)
no cell at all, but is a product of epithelial cells
|
Bhargavi Choudhury answered |
Basement membrane is a delicate noncellular layer made of extracellular material that lies below the epithelium in contact with its basal surface. Basement membrane is a delicate noncellular layer made of extracellular material that lies below the epithelium in contact with its basal surface. Besides this the basal lamina consists of mucopoly saccharides and very fine fibres.
The cell junctions called tight, adhering and gap junctions are found in[2009]- a)connective tissue
- b)epithelial tissue
- c)neural tissue
- d)muscular tissue
Correct answer is option 'B'. Can you explain this answer?
The cell junctions called tight, adhering and gap junctions are found in
[2009]
a)
connective tissue
b)
epithelial tissue
c)
neural tissue
d)
muscular tissue
|
Pankaj Banerjee answered |
The cell junctions called tight, adhering and gap junctions are found in epithelial tissue. Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial tissue that occurs on surfaces of the interior of the body is known as endothelium.
The breakdown of detritus into smaller particles by earthworm is a process called[2011M]- a)humification
- b)fragmentation
- c)mineralisation
- d)catabolism
Correct answer is option 'B'. Can you explain this answer?
The breakdown of detritus into smaller particles by earthworm is a process called
[2011M]
a)
humification
b)
fragmentation
c)
mineralisation
d)
catabolism
|
Abhiram Nair answered |
The break down of detritus into smaller particles by earthworm is known as fragmentation.
Histamine secreting cells are found in[1989]- a)connective tissues
- b)lungs
- c)muscular tissue
- d)nervous tissue
Correct answer is option 'A'. Can you explain this answer?
Histamine secreting cells are found in
[1989]
a)
connective tissues
b)
lungs
c)
muscular tissue
d)
nervous tissue
|
Subham Chavan answered |
In connective tissues, histamine is an organic nitrogen compound involved in local immune responses and regulating physiological function in the gut and acts as a neurotransmitter. Histamine is produced by basophils and by mast cells found in nearby connective tissues.
The functional unit of contractile system in striated muscle is[1998]- a)myofibril
- b)sarcomere
- c)Z-band
- d)cross bridges
Correct answer is option 'B'. Can you explain this answer?
The functional unit of contractile system in striated muscle is
[1998]
a)
myofibril
b)
sarcomere
c)
Z-band
d)
cross bridges
|
Surbhi Das answered |
A skeletal muscle consists of a bundle of long fibres running the length of the muscle. Each fibre is a single cell with many nuclei. Skeletal muscle is also called striated muscle because the regular arrangement of the myofilaments creates as repeating pattern of light and dark bands. Each repeating unit is a sarcomere, the basic functional unit of the muscle. The borders of the sarcomere the Z lines, are lined up in adjacent myofibrils and contribute to striations visible with a light microscope.
Open circulatory system is not of physiological hinderance in Cockroach because- a)Circulatory and respiratory systems are not connected
- b)Heart is simple but chambered
- c)blood is colourless
- d)Excretion occurs through malpighian tubules
Correct answer is option 'A'. Can you explain this answer?
Open circulatory system is not of physiological hinderance in Cockroach because
a)
Circulatory and respiratory systems are not connected
b)
Heart is simple but chambered
c)
blood is colourless
d)
Excretion occurs through malpighian tubules
|
Sandy Naaz answered |
The open circulatory system is a type of circulatory system in which nutrients and wastes move freely in the body cavity and not blood vessels. This type of circulatory system is found in insects, molluscs etc. In the case of cockroach, the open circulatory system is not of a physiological hindrance as circulatory and respiratory systems are not connected. Respiration mainly takes place by special respiratory organs known as spiracles. So, the correct answer is option A
Which one of the following contains the largest quantity of extracellular material?[2003]- a)Myelinated nerve fibres
- b)Striated muscle
- c)Areolar tissue
- d)Stratified epithelium
Correct answer is option 'C'. Can you explain this answer?
Which one of the following contains the largest quantity of extracellular material?
[2003]
a)
Myelinated nerve fibres
b)
Striated muscle
c)
Areolar tissue
d)
Stratified epithelium
|
|
Wahid Khan answered |
Areolar tissue is the least specialized connective tissue. It has a large amount of ground substance (extracellular material) and possesses rich blood and nerve supplies. It spreads extensively throughout the body, under the skin and epithelia, in between and around muscles, nerves and blood vessels and in the submucosa of
The kind of epithelium which forms the inner walls of blood vessels is :[2010]- a)cuboidal epithelium
- b)columnar epithelium
- c)ciliated columnar epithelium
- d)squamous epithelium
Correct answer is option 'D'. Can you explain this answer?
The kind of epithelium which forms the inner walls of blood vessels is :
[2010]
a)
cuboidal epithelium
b)
columnar epithelium
c)
ciliated columnar epithelium
d)
squamous epithelium
|
Arya Khanna answered |
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 gas, and in Bowman’s capsule of nephron for ultra filtration.
Blood capillary consists of[1993]- a)endothelium only
- b)endothelium and thin coat of connective tissue
- c)endothelium and thin coat of muscle fibres
- d)endothelium and thin coat of connective tissue plus muscle fibres
Correct answer is option 'A'. Can you explain this answer?
Blood capillary consists of
[1993]
a)
endothelium only
b)
endothelium and thin coat of connective tissue
c)
endothelium and thin coat of muscle fibres
d)
endothelium and thin coat of connective tissue plus muscle fibres
|
Aniket Chawla answered |
The wall of blood vessels (arteries & veins) are made up of mainly 3 layers – the outer most tunica externa has a loss connective tissue, collagen fibres, lymph vessels and the middle tunica media has circular smooth muscle fibres, some elastic fibres and the inner most tunica interna is a single layered endothelium of polyhedral squamous cells. If the arteries reach organs they form arterioles which are thinner and mainly consist smooth muscles and when they subdivide in the tissues they make capillaries. The wall of capillaries are very thin (usually less than one micron) and have numerous minute pores and made up of only endothelium. Exchange of material takes place between blood and tissue fluid across the endothelial membrane of capillaries through active diffusion.
Component of blood responsible for producing antibodies is[1992]- a)Thrombocytes
- b)Monocytes
- c)Erythrocytes
- d)Lymphocytes
Correct answer is option 'D'. Can you explain this answer?
Component of blood responsible for producing antibodies is
[1992]
a)
Thrombocytes
b)
Monocytes
c)
Erythrocytes
d)
Lymphocytes
|
|
Arnab Iyer answered |
Lymphocyte is a type of white blood cells in the vertebrate immune system.
Lymphocytes are responsible for making antibodies.
Lymphocytes are responsible for making antibodies.
Haversian canals occur in[1989]- a)Humerus
- b)Pubis
- c)Scapula
- d)Clavicle
Correct answer is option 'A'. Can you explain this answer?
Haversian canals occur in
[1989]
a)
Humerus
b)
Pubis
c)
Scapula
d)
Clavicle
|
Rajeev Sharma answered |
Haversian canals are a characteristic feature of the mammalian bones present in the matrix of bones. They are present in Humerus bone
Characteristics of smooth muscle fibres are[1990]- a)spindle-shaped, unbranched, unstriated, uninucleate and involuntary
- b)spindle shaped, unbranched, unstriped, multinucleate and involuntary
- c)cylindrical, unbranched, unstriped, multinucleate and involuntary
- d)cylindrical, unbranched, striated, multinucleate and voluntary
Correct answer is option 'A'. Can you explain this answer?
Characteristics of smooth muscle fibres are
[1990]
a)
spindle-shaped, unbranched, unstriated, uninucleate and involuntary
b)
spindle shaped, unbranched, unstriped, multinucleate and involuntary
c)
cylindrical, unbranched, unstriped, multinucleate and involuntary
d)
cylindrical, unbranched, striated, multinucleate and voluntary
|
|
Wahid Khan answered |
Characteristics of smooth muscle fibres.
cells range from 5 to 10 µm in diameter and 30 to 200 µm in length
spindle-shaped
single, centrally located nucleus
smooth muscle tissue occurs within almost every organ, forming sheets, bundles or sheaths around other tissues.
Smooth muscle differs from both skeletal and cardiac muscle tissues in structure and function. Sarcomeres or myofibrils are not present - therefore not striated, ie. smooth.
cells range from 5 to 10 µm in diameter and 30 to 200 µm in length
spindle-shaped
single, centrally located nucleus
smooth muscle tissue occurs within almost every organ, forming sheets, bundles or sheaths around other tissues.
Smooth muscle differs from both skeletal and cardiac muscle tissues in structure and function. Sarcomeres or myofibrils are not present - therefore not striated, ie. smooth.
Which cartilage is present at the end of long bones?[2002] - a)Calcified cartilage
- b)Hyaline cartilage
- c)Elastic cartilage
- d)Fibrous cartilage
Correct answer is option 'B'. Can you explain this answer?
Which cartilage is present at the end of long bones?
[2002]
a)
Calcified cartilage
b)
Hyaline cartilage
c)
Elastic cartilage
d)
Fibrous cartilage
|
Sarthak Saini answered |
Hyaline cartilage is present at the end of long articular bones. It provides a smooth articular surface to permit movement at joints. Elastic cartilage is found where support with flexibility is needed such as in external ears.
Fibro cartilage is a very tough substance and is used in places of the body where shock absorbers are needed.
Examples – Discs between vertebrate and in the knee joints.
Fibro cartilage is a very tough substance and is used in places of the body where shock absorbers are needed.
Examples – Discs between vertebrate and in the knee joints.
The polysaccharide present in the matrix of cartilage is known as[2000]- a)cartilagin
- b)ossein
- c)chondriotin
- d)casein
Correct answer is option 'C'. Can you explain this answer?
The polysaccharide present in the matrix of cartilage is known as
[2000]
a)
cartilagin
b)
ossein
c)
chondriotin
d)
casein
|
Diya Datta answered |
The chief component of ground substance of cartilage is chondromuco protein which is formed of chondriotin sulphate, keratan sulphate and hyaluronic acid.
The layer of actively dividing cells of skin is termed as[1993]- a)stratum compactum
- b)stratum corneum
- c)stratum malpighii/ stratum germinativum
- d)stratum lucidum
Correct answer is option 'C'. Can you explain this answer?
The layer of actively dividing cells of skin is termed as
[1993]
a)
stratum compactum
b)
stratum corneum
c)
stratum malpighii/ stratum germinativum
d)
stratum lucidum
|
Dipika Das answered |
It is the innermost one celled thick made up of columnar epithelial cells. It lies on a basement. These cells are active & continuously produce new cells by mitotic division that is why called germinative layer or stratum germinativum. The division rate of these cells in highest during sleep or rest and lowest during muscular activity & stress.
Select the correct statement from the ones given below with respect to Periplaneta americana.[2012]- a)Nervous system located dorsally, consists of segmentally arranged ganglia joined by a pair of longitudinal connectives.
- b)Males bear a pair of short thread like anal styles.
- c)There are 16 very long Malpighian tubules present at the junctions of midgut and hindgut.
- d)Grinding of food is carried out only by the mouth parts.
Correct answer is option 'B'. Can you explain this answer?
Select the correct statement from the ones given below with respect to Periplaneta americana.
[2012]
a)
Nervous system located dorsally, consists of segmentally arranged ganglia joined by a pair of longitudinal connectives.
b)
Males bear a pair of short thread like anal styles.
c)
There are 16 very long Malpighian tubules present at the junctions of midgut and hindgut.
d)
Grinding of food is carried out only by the mouth parts.
|
Akshita Pillai answered |
Males bear a pair of short, thread-like anal styles which are absent in females, anal/caudal styles arise from the 9th abdominal segment in the male cockroach.
So, the correct option is 'Males bear a pair of short thread-like anal styles'.
Protein present in the matrix of cartilage is known as[1997]- a)chondrin
- b)casein
- c)cartilagin
- d)ossein
Correct answer is option 'A'. Can you explain this answer?
Protein present in the matrix of cartilage is known as
[1997]
a)
chondrin
b)
casein
c)
cartilagin
d)
ossein
|
|
Diya Datta answered |
Chondrin is a gelatin-like substance and can be obtained by boiling cartilage in water. The cartilage is a connective tissue that contains cells embedded in a matrix of chondrin.
A piece of bone such as femur of frog if kept in dilute HCl for about a week will[2000]- a)assume black colour
- b)shrink in size
- c)turn flexible
- d)crack into pieces
Correct answer is option 'C'. Can you explain this answer?
A piece of bone such as femur of frog if kept in dilute HCl for about a week will
[2000]
a)
assume black colour
b)
shrink in size
c)
turn flexible
d)
crack into pieces
|
|
Arnab Iyer answered |
When a bone is kept in dilute acids like HCl for a few days, the Ca salts get dissolved leaving only the soft and flexible organic matrix. This process is called Decalcification. If a bone is kept in KOH it remains unaffected and only the surrounding muscles and connective tissues get dissolved so that the bone now appears clean.
In which one of the following preparations are your likely to come across cell junctions most frequently ?[2007]- a)Thrombocytes
- b)Tendon
- c)Hyaline cartilage
- d)Ciliated epithelium.
Correct answer is option 'D'. Can you explain this answer?
In which one of the following preparations are your likely to come across cell junctions most frequently ?
[2007]
a)
Thrombocytes
b)
Tendon
c)
Hyaline cartilage
d)
Ciliated epithelium.
|
Nayanika Dasgupta answered |
It is ciliated epithelium which bears numerous delicated hair like outgrowths the cilia, arising from basal granules. The cilia remains in rhythmic motion and creates current to transport the materials which comes in contact with them
Which of the following features is used to identify a male cockroach from a female cockroach? [2018]- a)Presence of a boat-shaped sternum on the 9th abdominal segment.
- b)Presence of caudal styles
- c)Forewings with darker tegmina
- d)Presence of anal cerci
Correct answer is option 'B'. Can you explain this answer?
Which of the following features is used to identify a male cockroach from a female cockroach? [2018]
a)
Presence of a boat-shaped sternum on the 9th abdominal segment.
b)
Presence of caudal styles
c)
Forewings with darker tegmina
d)
Presence of anal cerci
|
|
Preeti Iyer answered |
Male cockroach bears a pair of short thread-like anal/caudal styles which are absent in females. They project backwardly from the sides of 9th abdominal segment in male cockroach.
The active molecule that helps initiate the inflammatory response when mast cells degranulate is[1999]- a)perforin
- b)histamine
- c)heparin
- d)insulin
Correct answer is option 'B'. Can you explain this answer?
The active molecule that helps initiate the inflammatory response when mast cells degranulate is
[1999]
a)
perforin
b)
histamine
c)
heparin
d)
insulin
|
Charvi Shah answered |
Mast cells contain granules of heparin and histamine. Heparin prevents blood clotting. Histamine produces inflammation.
Which of the following substances, if introduced into the blood stream, would cause coagulation of blood at the site of its introduction?[2005]- a)Prothrombin
- b)Fibrinogen
- c)Thromboplastin
- d)Heparin
Correct answer is option 'C'. Can you explain this answer?
Which of the following substances, if introduced into the blood stream, would cause coagulation of blood at the site of its introduction?
[2005]
a)
Prothrombin
b)
Fibrinogen
c)
Thromboplastin
d)
Heparin
|
|
Arya Khanna answered |
Fibrinogen, prothrombin, throm- boplastin are respectively clotting factors I, II and III.
Thromboplastin released from injured platelets or injured tissue. This converts prothrombin into thrombin in the presence of calcium ions. The thrombin converts fibrinogen into fibrin and the latter froms the clot.
Thromboplastin released from injured platelets or injured tissue. This converts prothrombin into thrombin in the presence of calcium ions. The thrombin converts fibrinogen into fibrin and the latter froms the clot.
Which cells do not form layer and remain structurally separate?[2001]- a)Epithelial cells
- b)Muscle cells
- c)Nerve cells
- d)Gland cells
Correct answer is option 'C'. Can you explain this answer?
Which cells do not form layer and remain structurally separate?
[2001]
a)
Epithelial cells
b)
Muscle cells
c)
Nerve cells
d)
Gland cells
|
Ashwini Khanna answered |
Only nerve cells do not form layers. These also remain structurally separate from each other. Nerve cells or neurons are the cells specialized to conduct an electrochemical current. Nerve tissue is made up of these cells and supporting cells. Epithelial tissue is made of one or a few layers of compactly arranged cells overlying a basement membrane. Glands are epithelial cells specialized to elaborate and release chemicals for use in the body. Muscle tissue is made of elongated and contractile cells called myocytes.
Bowman’s glands are found in[2006]- a)external auditory canal
- b)cortical nephrons only
- c)juxtamedullary nephrons
- d)olfactory epithelium
Correct answer is option 'D'. Can you explain this answer?
Bowman’s glands are found in
[2006]
a)
external auditory canal
b)
cortical nephrons only
c)
juxtamedullary nephrons
d)
olfactory epithelium
|
Arya Nair answered |
Bowman’s glands are found in olfactory epithelium which secrete mucus to keep the olfactory epithelium moist and free from germs.
Simple epithelium is a tissue in which the cells are[2000]- a)hardened and provide support to the organs
- b)cemented directly to one another to form a single layer
- c)continuously dividing to provide form to an organ
- d)loosely connected to one another to form an irregular organ
Correct answer is option 'B'. Can you explain this answer?
Simple epithelium is a tissue in which the cells are
[2000]
a)
hardened and provide support to the organs
b)
cemented directly to one another to form a single layer
c)
continuously dividing to provide form to an organ
d)
loosely connected to one another to form an irregular organ
|
|
Surbhi Das answered |
Simple epithelium is a tissue made of a single layer of compactly arranged cells all of which rest over a noncellular basement membrane.
The ciliated columnar epithelial cells in humans are known to occur in :
[2011]
- a)eustachian tube and stomach lining
- b)bronchioles and fallopian tubes
- c)bile duct and oesophagus
- d)fallopian tubes and urethra
Correct answer is option 'B'. Can you explain this answer?
The ciliated columnar epithelial cells in humans are known to occur in :
[2011]
a)
eustachian tube and stomach lining
b)
bronchioles and fallopian tubes
c)
bile duct and oesophagus
d)
fallopian tubes and urethra
|
|
Arya Nair answered |
The ciliated columnar epithelial cells in humans are known to occur in bronchioles and fallopian tube. The cilia move back and forth to help the movement of particles over the epithelial surface.
Thus, the correct answer is option B.
ATPase enzyme needed for muscle contraction is located in[2004]- a)actinin
- b)troponin
- c)myosin
- d)actin
Correct answer is option 'C'. Can you explain this answer?
ATPase enzyme needed for muscle contraction is located in
[2004]
a)
actinin
b)
troponin
c)
myosin
d)
actin
|
|
Devika Pillai answered |
The correct answer is option 'C' - troponin.
Muscle contraction is a complex process that involves the interaction of several proteins. One of the key proteins involved in muscle contraction is troponin. Troponin is a regulatory protein that is found in skeletal and cardiac muscle cells.
- The role of ATP in muscle contraction:
ATP (adenosine triphosphate) is the energy currency of the cell. It provides energy for various cellular processes, including muscle contraction. ATP is required for muscle contraction as it powers the movement of the myosin heads, which are responsible for the sliding of the actin and myosin filaments.
- The role of ATPase enzyme:
ATPase is an enzyme that catalyzes the hydrolysis of ATP to ADP (adenosine diphosphate) and inorganic phosphate (Pi). This hydrolysis reaction releases energy that is used by the myosin heads to change their conformation and perform mechanical work. In the context of muscle contraction, ATPase is specifically referred to as myosin ATPase, as it is associated with the myosin protein.
- The location of ATPase enzyme:
The myosin ATPase enzyme is located on the myosin heads, which are part of the thick myosin filaments in muscle cells. Myosin heads interact with actin filaments during muscle contraction. Troponin, on the other hand, is a regulatory protein that is located on the actin filaments. It plays a crucial role in controlling the interaction between actin and myosin during muscle contraction.
- The role of troponin in muscle contraction:
Troponin consists of three subunits - troponin C, troponin I, and troponin T. Troponin C binds to calcium ions, troponin I inhibits the interaction between actin and myosin, and troponin T anchors troponin to the actin filament. When calcium ions are released in response to a nerve signal, they bind to troponin C, causing a conformational change in troponin. This change in troponin exposes the binding sites on the actin filament, allowing the myosin heads to bind and initiate muscle contraction.
In conclusion, the ATPase enzyme required for muscle contraction is located on the myosin heads, while troponin is a regulatory protein located on the actin filaments. Troponin plays a crucial role in controlling the interaction between actin and myosin during muscle contraction.
Muscle contraction is a complex process that involves the interaction of several proteins. One of the key proteins involved in muscle contraction is troponin. Troponin is a regulatory protein that is found in skeletal and cardiac muscle cells.
- The role of ATP in muscle contraction:
ATP (adenosine triphosphate) is the energy currency of the cell. It provides energy for various cellular processes, including muscle contraction. ATP is required for muscle contraction as it powers the movement of the myosin heads, which are responsible for the sliding of the actin and myosin filaments.
- The role of ATPase enzyme:
ATPase is an enzyme that catalyzes the hydrolysis of ATP to ADP (adenosine diphosphate) and inorganic phosphate (Pi). This hydrolysis reaction releases energy that is used by the myosin heads to change their conformation and perform mechanical work. In the context of muscle contraction, ATPase is specifically referred to as myosin ATPase, as it is associated with the myosin protein.
- The location of ATPase enzyme:
The myosin ATPase enzyme is located on the myosin heads, which are part of the thick myosin filaments in muscle cells. Myosin heads interact with actin filaments during muscle contraction. Troponin, on the other hand, is a regulatory protein that is located on the actin filaments. It plays a crucial role in controlling the interaction between actin and myosin during muscle contraction.
- The role of troponin in muscle contraction:
Troponin consists of three subunits - troponin C, troponin I, and troponin T. Troponin C binds to calcium ions, troponin I inhibits the interaction between actin and myosin, and troponin T anchors troponin to the actin filament. When calcium ions are released in response to a nerve signal, they bind to troponin C, causing a conformational change in troponin. This change in troponin exposes the binding sites on the actin filament, allowing the myosin heads to bind and initiate muscle contraction.
In conclusion, the ATPase enzyme required for muscle contraction is located on the myosin heads, while troponin is a regulatory protein located on the actin filaments. Troponin plays a crucial role in controlling the interaction between actin and myosin during muscle contraction.
Afferent nerve fibre carries impulses from [1992]- a)effector to central nervous system
- b)receptor to central nervous system
- c)central nervous system to muscles
- d)central nervous system to receptors
Correct answer is option 'B'. Can you explain this answer?
Afferent nerve fibre carries impulses from
[1992]
a)
effector to central nervous system
b)
receptor to central nervous system
c)
central nervous system to muscles
d)
central nervous system to receptors
|
|
Surbhi Das answered |
In nervous system afferent nerve fibres carry nerve impulse from receptors or sense organs towards the central nervous system.
Which one of the following correctly describes the location of some body parts in the earthworm Pheretima ?[2009]- a)Four pairs of spermathecae in 4 - 7 segments.
- b)One pair of ovaries attached at intersegmental septum of 14th and 15th segments.
- c)Two pairs of testes in 10th and 11th segments.
- d)Two pairs of accessory glands in 16 - 18 segments.
Correct answer is option 'C'. Can you explain this answer?
Which one of the following correctly describes the location of some body parts in the earthworm Pheretima ?
[2009]
a)
Four pairs of spermathecae in 4 - 7 segments.
b)
One pair of ovaries attached at intersegmental septum of 14th and 15th segments.
c)
Two pairs of testes in 10th and 11th segments.
d)
Two pairs of accessory glands in 16 - 18 segments.
|
|
Nayanika Dasgupta answered |
In Pheretima two pairs of testes sacs are situated in the 10th and 11th segments. Each testes sac of the 10th segment encloses a testes and a seminal funnel. Each testes sac of the 11th segment encloses a testes, a seminal vesicle and a seminal funnel.
Compared to those of humans, the erythrocytes in frog are[2012]- a)Without nucleus but with haemoglobin
- b)nucleated and with haemoglobin
- c)very much smaller and fewer
- d)nucleated and without haemoglobin.
Correct answer is option 'C'. Can you explain this answer?
Compared to those of humans, the erythrocytes in frog are
[2012]
a)
Without nucleus but with haemoglobin
b)
nucleated and with haemoglobin
c)
very much smaller and fewer
d)
nucleated and without haemoglobin.
|
Raghav Khanna answered |
The erythrocytes or RBCs in frog are large, oval and biconvex nucleated cell with respiratory red pigment haemoglobin in its cytoplasm.
Earthworms have no skeleton but during burrowing, the anterior end becomes turgid and acts as a hydraulic skeleton. It is due to [2008]- a)coelomic fluid
- b)blood
- c)gut peristalsis
- d)setae
Correct answer is option 'A'. Can you explain this answer?
Earthworms have no skeleton but during burrowing, the anterior end becomes turgid and acts as a hydraulic skeleton. It is due to
[2008]
a)
coelomic fluid
b)
blood
c)
gut peristalsis
d)
setae
|
Sushant Goyal answered |
Earthworms have no skeleton but during burrowing, anterior end becomes turgid and acts as a hydraulic skeleton. It is due to coelomic fluid. The coelom is filled with an alkaline milky coelomic fluid. This coelomic fliud contains water, salts, proteins and 4 types of cells namely amoebocytes, mucocytes, circular cells and chloragogen cells.
Which of the following statements wrongly represents the nature of smooth muscle? [2021]- a)Communication among the cells is performed by intercalated discs
- b)These muscles are present in the wall of blood vessels
- c)These muscle have no striations
- d)They are involuntary muscles
Correct answer is option 'A'. Can you explain this answer?
Which of the following statements wrongly represents the nature of smooth muscle? [2021]
a)
Communication among the cells is performed by intercalated discs
b)
These muscles are present in the wall of blood vessels
c)
These muscle have no striations
d)
They are involuntary muscles
|
Hansa Sharma answered |
- The smooth muscle fibres taper at both ends (fusiform) and do not show striations.
- The wall of internal organs such as the blood vessels, stomach and intestine contains this type of muscle tissue.
- Smooth muscles are ‘involuntary’ as their functioning cannot be directly controlled.
Which of the following is correctly stated as it happens in the common cockroach ? [2011]- a)Malpighian tubules are excretory organs projecting out from the colon
- b)Oxygen is transported by haemoglobin in blood
- c)Nitrogenous excretory product is urea
- d)The food is ground by mandibles and gizzard
Correct answer is option 'D'. Can you explain this answer?
Which of the following is correctly stated as it happens in the common cockroach ?
[2011]
a)
Malpighian tubules are excretory organs projecting out from the colon
b)
Oxygen is transported by haemoglobin in blood
c)
Nitrogenous excretory product is urea
d)
The food is ground by mandibles and gizzard
|
Ishaan Menon answered |
Cockroach takes the food after grounding by its mandibles and gizzard.
Mast cells of connective tissue contain[2004]- a)vasopressin and relaxin
- b)heparin and histamine
- c)heparin and calcitonin
- d)serotonin and melanin
Correct answer is option 'B'. Can you explain this answer?
Mast cells of connective tissue contain
[2004]
a)
vasopressin and relaxin
b)
heparin and histamine
c)
heparin and calcitonin
d)
serotonin and melanin
|
Krithika Sharma answered |
Mast cells are a type of white blood cell found in connective tissue. They play a crucial role in the immune response and the inflammatory process. Mast cells are best known for their ability to release various chemical substances, including heparin and histamine.
1. Heparin:
- Heparin is an anticoagulant, which means it prevents blood clotting.
- It is produced and stored in mast cells within connective tissue.
- Heparin helps to inhibit the formation of blood clots, preventing them from becoming too large and potentially causing blockages in blood vessels.
- Its release from mast cells is especially important during an allergic reaction or inflammation when blood vessels may become damaged.
2. Histamine:
- Histamine is a compound that plays a critical role in the immune response and inflammation.
- It is released from mast cells in response to various triggers, such as allergens, pathogens, or injury.
- Histamine causes blood vessels to dilate, leading to increased blood flow to the affected area.
- It also increases vascular permeability, allowing immune cells and antibodies to reach the site of injury or infection more easily.
- Histamine is responsible for many of the symptoms associated with an allergic reaction, such as itching, redness, swelling, and increased mucus production.
3. Other Substances:
- Mast cells also contain other substances that they can release, including leukotrienes, prostaglandins, cytokines, and growth factors.
- These substances further contribute to the immune response and inflammation by attracting and activating other immune cells, promoting cell proliferation, and modulating the inflammatory process.
In conclusion, mast cells of connective tissue contain heparin and histamine. Heparin acts as an anticoagulant, preventing blood clotting, while histamine plays a crucial role in the immune response and inflammation. The release of these substances from mast cells helps to regulate and coordinate the body's response to injury, infection, or allergens.
1. Heparin:
- Heparin is an anticoagulant, which means it prevents blood clotting.
- It is produced and stored in mast cells within connective tissue.
- Heparin helps to inhibit the formation of blood clots, preventing them from becoming too large and potentially causing blockages in blood vessels.
- Its release from mast cells is especially important during an allergic reaction or inflammation when blood vessels may become damaged.
2. Histamine:
- Histamine is a compound that plays a critical role in the immune response and inflammation.
- It is released from mast cells in response to various triggers, such as allergens, pathogens, or injury.
- Histamine causes blood vessels to dilate, leading to increased blood flow to the affected area.
- It also increases vascular permeability, allowing immune cells and antibodies to reach the site of injury or infection more easily.
- Histamine is responsible for many of the symptoms associated with an allergic reaction, such as itching, redness, swelling, and increased mucus production.
3. Other Substances:
- Mast cells also contain other substances that they can release, including leukotrienes, prostaglandins, cytokines, and growth factors.
- These substances further contribute to the immune response and inflammation by attracting and activating other immune cells, promoting cell proliferation, and modulating the inflammatory process.
In conclusion, mast cells of connective tissue contain heparin and histamine. Heparin acts as an anticoagulant, preventing blood clotting, while histamine plays a crucial role in the immune response and inflammation. The release of these substances from mast cells helps to regulate and coordinate the body's response to injury, infection, or allergens.
One very special feature in the earthworm Pheretima is that[2011]- a)fertilisation for eggs occurs inside the body
- b)the typhlosole greatly increases the effective absorption area of the digested food in the intestine
- c)the S- shaped setae embedded in the integument are the defensive weapons used against the enemies
- d)it has a long dorsal tubular heart
Correct answer is option 'B'. Can you explain this answer?
One very special feature in the earthworm Pheretima is that
[2011]
a)
fertilisation for eggs occurs inside the body
b)
the typhlosole greatly increases the effective absorption area of the digested food in the intestine
c)
the S- shaped setae embedded in the integument are the defensive weapons used against the enemies
d)
it has a long dorsal tubular heart
|
Shalini Saha answered |
The intestine of an earthworm has a peculiar fold of tissue that forms a pocket in the intestine that is visible when viewing a cross section. This space, which runs almost the whole length of the body dorsally is known as the typhlosole and it serves to increase the surface area of the intestine for absorption.
Mast cells secrete[2006]- a)myoglobin
- b)histamine
- c)hemoglobin
- d)hippurin
Correct answer is option 'B'. Can you explain this answer?
Mast cells secrete
[2006]
a)
myoglobin
b)
histamine
c)
hemoglobin
d)
hippurin
|
|
Pankaj Banerjee answered |
At the site of infection, the infectious organism release some chemical to increase the flow of mast cells towards the inflammation site. Mast cell release histamine which increases the permeability of blood vessels at the site of inflammation so that more blood supply takes place. The site gets warm and red due to this.
Areolar connective tissue joins[2006]- a)integument with muscles
- b)bones with muscles
- c)bones with bones
- d)fat body with muscles
Correct answer is option 'A'. Can you explain this answer?
Areolar connective tissue joins
[2006]
a)
integument with muscles
b)
bones with muscles
c)
bones with bones
d)
fat body with muscles
|
|
Shalini Saha answered |
Areolar connective tissue has rich supply of nerve fibres and blood vessels. It joins skin epithelia with muscles, nerves & blood vessels. Binding of body parts together is the main function of areolar connective tissue.
Select the cor rect option with respect to cockroaches
[NEET Kar. 2013]
- a)The fore wings are tegmina which are used in flight
- b)Malpighian tubules convert nitrogenous wastes into urea
- c)Males bear short anal styles not present in females
- d)Nervous system comprises of a dorsal nerve cord and ten pairs of ganglion
Correct answer is option 'C'. Can you explain this answer?
Select the cor rect option with respect to cockroaches
[NEET Kar. 2013]
a)
The fore wings are tegmina which are used in flight
b)
Malpighian tubules convert nitrogenous wastes into urea
c)
Males bear short anal styles not present in females
d)
Nervous system comprises of a dorsal nerve cord and ten pairs of ganglion
|
|
Ashwini Khanna answered |
A. Males bear short oval styles not present in females
EXPLANATION: Male and female cockroaches can be distinguished externally by the presence of anal styles. It is present in male cockroach, but not in female cockroach. The abdomen of male cockroach is slender and the last segment of the abdomen is pointed. In the 9th sternum of the abdomen of male cockroach un-jointed anal style is present.
Frog’s heart when taken out of the body continues to beat for some time.
Select the best option from the following statements. [2017]
(1) Frog is a poikilotherm.
(2) Frog does not have any coronary circulation.
(3) Heart is “myogenic” in nature.
(4) Fleart is autoexcitable.- a)Only (4)
- b)(1) and (2)
- c)(3) and (4)
- d)Only (3)
Correct answer is option 'C'. Can you explain this answer?
Frog’s heart when taken out of the body continues to beat for some time.
Select the best option from the following statements. [2017]
(1) Frog is a poikilotherm.
(2) Frog does not have any coronary circulation.
(3) Heart is “myogenic” in nature.
(4) Fleart is autoexcitable.
Select the best option from the following statements. [2017]
(1) Frog is a poikilotherm.
(2) Frog does not have any coronary circulation.
(3) Heart is “myogenic” in nature.
(4) Fleart is autoexcitable.
a)
Only (4)
b)
(1) and (2)
c)
(3) and (4)
d)
Only (3)
|
Mira Joshi answered |
Frog’s heart is myogenic, i.e., heartbeat originates from muscles of heart. Hence, it is autorythmic. Wave of contraction originates from sinus venosus and spreads to wall of sinus venosus and both auricles. This compels the heart to beat. Due to this reason, frog’s heart will continue to beat as long as it gets supply of ATP.
Which one of the following structures in Pheretima is correctly matched with its function?[2011M]- a)Clitellum - secretes cocoon
- b)Gizzard - absorbs digested food
- c)Setae- defence against predators
- d)Typhlosole - storage of extra nutrients
Correct answer is option 'A'. Can you explain this answer?
Which one of the following structures in Pheretima is correctly matched with its function?
[2011M]
a)
Clitellum - secretes cocoon
b)
Gizzard - absorbs digested food
c)
Setae- defence against predators
d)
Typhlosole - storage of extra nutrients
|
|
Nayanika Dasgupta answered |
Clitellum - secretes cocoon during breading season of earthworm. Gizzard -grinding of food particles. Setae help in locomotion. Typhlosole increases the absorption area in intestine
If a live earthworm is pricked with a needle on it outer surface without damaging its gut, the fluid that comes out is :[2009]- a)coelomic fluid
- b)haemolymph
- c)slimy mucus
- d)excretory fluid
Correct answer is option 'A'. Can you explain this answer?
If a live earthworm is pricked with a needle on it outer surface without damaging its gut, the fluid that comes out is :
[2009]
a)
coelomic fluid
b)
haemolymph
c)
slimy mucus
d)
excretory fluid
|
|
Arya Nair answered |
If a live earthworm is pricked with a needle on its outer surface without damaging its gut, the fluid that comes out is coelomic fluid because coelomic fluid lies between body wall and alimentary canal. Earthworms are helpful to man as bait for fishing and loosen the soil for roots to grow. A earthworm’s wastes help to fertilize the soil.
Which one of the following is correct pairing of a body part and the kind of muscle tissue that moves it ?[2009]- a)Biceps of upper arm–Smooth muscle fibres
- b) Iris–Involuntary smooth muscle
- c)Abdominal wall–Smooth muscle
- d)Heart wall–Involuntary unstriated muscle
Correct answer is option 'B'. Can you explain this answer?
Which one of the following is correct pairing of a body part and the kind of muscle tissue that moves it ?
[2009]
a)
Biceps of upper arm–Smooth muscle fibres
b)
Iris–Involuntary smooth muscle
c)
Abdominal wall–Smooth muscle
d)
Heart wall–Involuntary unstriated muscle
|
|
Athul Iyer answered |
There are three types of muscles found in human body, namely skeletal muscle, smooth muscle and cardiac muscle. Skeletal muscles are also called as striated muscles. They are attached to the bone and helps in the movement of skeleton. These muscles are voluntary muscles as they are under voluntary control of somatic nervous system. Examples of skeletal muscle are muscles of arms and legs, muscles of abdomen and back. Smooth muscles are involuntary muscles as they are not controlled voluntarily. They are also called as unstriated muscles as they do not have stripes appearance as in case of skeletal muscle. Examples of smooth muscles include walls of stomach, oesophagus, bronchi and iris. Involuntary smooth muscle of iris helps to adjust pupil size. Cardiac muscles are found only in the walls of the heart. These are involuntary muscles.
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