Animal Tissues Questions in English

(C) Muscular tissue is responsible for movement in our body. It consists of specialized cells called muscle fibers that have the ability to contract and relax,which facilitates body movement and locomotion.

(A) neuron consists of a cell body (cyton) containing a nucleus and cytoplasm.
It has two types of extensions: axons and dendrites.
Each neuron has a single long process called the axon and many short,branched processes called dendrites.
Many nerve fibers are bound together by connective tissue to form a nerve.

(N/A) The features of cardiac muscles are as follows:
$1.$ These are involuntary muscles that exhibit rhythmic contraction and relaxation throughout life.
$2.$ The cells are cylindrical,branched,and uninucleate,possessing faint cross-striations.
$3.$ These muscles do not get fatigued under normal physiological conditions.

(N/A) Functions of areolar tissue :
$1.$ It fills the space inside the organs,thus acts as a packing tissue between the organs.
$2.$ It supports many delicate organs in the body.
$3.$ It plays a role in the repair of tissues.

(N/A) The three types of muscle fibres are:
$1.$ Striated muscle: These are cylindrical,unbranched,and multinucleated cells with alternating light and dark bands (striations).
$2.$ Smooth muscle: These are spindle-shaped,uninucleated cells that lack striations and are found in the walls of internal organs.
$3.$ Cardiac muscle: These are cylindrical,branched,and uninucleated cells with faint striations,found exclusively in the heart.

(B) The uninucleated,striated,tubular,and branched muscles that form the wall of the heart are known as cardiac muscles.
They serve to bring about rhythmic contraction and relaxation of the heart to allow the pumping of blood throughout life.
Since these muscles contract without any nerve stimulation or conscious control,they are involuntary in nature.

(N/A) The differences between the three types of muscles are as follows:
$1$. Striated (Skeletal) Muscles: These are cylindrical,unbranched,and multinucleated cells with light and dark bands (striations). They are attached to bones and are responsible for voluntary movements.
$2$. Unstriated (Smooth) Muscles: These are spindle-shaped,uninucleated,and lack striations. They are found in the walls of internal organs like the stomach,intestines,and blood vessels,and are responsible for involuntary movements.
$3$. Cardiac Muscles: These are cylindrical,branched,and uninucleated cells with faint striations. They are found exclusively in the walls of the heart and are responsible for the rhythmic contraction and relaxation of the heart throughout life.

(N/A) neuron (nerve cell) consists of three main parts: the cell body (cyton),dendrites,and the axon.
$1$. Cell body (Cyton): It contains the nucleus and cytoplasm. It is the metabolic center of the neuron.
$2$. Dendrites: These are short,branched extensions that receive signals from other neurons or sensory receptors.
$3$. Axon: It is a long,slender projection that conducts electrical impulses away from the cell body.
Key structures include the myelin sheath (insulating layer),nodes of Ranvier (gaps in the myelin sheath),and the motor end plate (synaptic terminal) which transmits signals to the next cell.

(A) The intestine is lined with columnar epithelium,which is specialized for absorption and secretion.
Stratified squamous epithelium is found in the skin and provides protection against wear and tear.
Cuboidal epithelium is typically found in ducts of glands and kidney tubules,providing structural support and secretion.
Spindle fibres are part of the cytoskeleton involved in cell division,not a type of epithelial tissue.

(B) Ligaments are specialized connective tissues that connect one bone to another bone at joints. When a person meets with an accident,the excessive force can cause these ligaments to tear or break. Since ligaments provide stability to the joints,their rupture leads to the displacement of bones from their normal position,which is known as dislocation.

(C) Skeletal muscles are responsible for voluntary movement,and therefore,movement in limbs like hands and legs is facilitated by the contraction or relaxation of skeletal muscles.
$A$ tendon is a fibrous connective tissue that attaches a muscle to a bone.
When skeletal muscles contract,they pull on the tendons,which in turn pull the bones to create movement.
Therefore,option $C$ is correct.

(D) Muscles can be classified based on their control as voluntary or involuntary.
Skeletal muscles are voluntary muscles because their movement is under our conscious control. They are also known as striated muscles due to their striped appearance.
Smooth muscles are involuntary muscles found in the walls of internal organs,and their movement is not under conscious control.
Cardiac muscles are involuntary muscles found in the heart,responsible for rhythmic contractions.
Therefore,both smooth muscles $(ii)$ and cardiac muscles $(iii)$ act involuntarily.

(C) Tendons are fibrous connective tissues that are very strong and have limited flexibility,not fragile. Therefore,the statement that tendons are non-fibrous and fragile is incorrect.

(D) Cartilage is a type of specialized connective tissue. It is found in the nose,ear,larynx,and trachea. The kidney is an organ composed primarily of epithelial tissues and nephrons,not cartilage.

(A) Adipose tissue is a specialized type of connective tissue that functions primarily to store fat. It consists of adipocytes,which are cells specialized for the storage of lipids. These tissues are found beneath the skin,around internal organs,and in the bone marrow,providing insulation and energy reserves for the body.

(B) Bone is a connective tissue that provides a structural framework to the body. The bone cells (osteocytes) are embedded in a hard,non-pliable matrix. This matrix is primarily composed of calcium and phosphorus salts,which provide strength and rigidity to the bones.

(C) Muscles possess the unique ability to contract and relax,which allows for movement. This property is due to the presence of specialized contractile proteins,primarily $Actin$ and $Myosin$,within the muscle fibers. Therefore,contractile proteins are found in muscles.

(D) Voluntary muscles,also known as skeletal muscles,are attached to bones and are under our conscious control.
They are responsible for the movement of body parts like arms and legs.
The muscles in the alimentary canal,bronchi of lungs,and iris of the eye are involuntary muscles,meaning they are not under our conscious control.

(A) Nervous tissue is primarily composed of neurons and neuroglia, which are responsible for the transmission and processing of electrical signals. The $brain$, $spinal cord$, and $nerves$ are the primary components of the nervous system and are rich in nervous tissue. $Tendons$, on the other hand, are a type of dense regular connective tissue that connects muscles to bones. Therefore, nervous tissue is not found in tendons.

(B) nerve cell,also known as a neuron,is the fundamental unit of the nervous system. It consists of a cell body (cyton),dendrites,and an axon with nerve endings. Tendons are a type of dense regular connective tissue that connects muscle to bone. Therefore,tendons are not a component of a nerve cell.

(C) Areolar tissue is a type of loose connective tissue that acts as a supporting and packing tissue between organs. It fills the space inside the organs,supports internal organs,and plays a crucial role in the repair of tissues after an injury.

(D) Cardiac muscles are involuntary muscles present in the heart.
They are specialized to contract and relax rhythmically throughout an individual's life without getting fatigued.
This continuous action ensures that the heart keeps pumping blood to all parts of the body without stopping.

(A) Chondrocytes are the specialized cells found in the cartilaginous tissue (cartilage) of the body.
$A$. Chondrocytes: Found in cartilage.
$B$. Basophils: $A$ type of white blood cell found in the blood.
$C$. Osteocytes: Mature bone cells found in bone tissue.
$D$. Mast cells: Found in connective tissues like areolar tissue.

(A) Epithelial tissues do not have intercellular spaces between them. Instead,the cells are tightly packed together to form a continuous sheet with very little intercellular material.

(N/A) The subcutaneous fat layer acts as an insulator for the body.
It prevents the loss of body heat to the cold environment.
This process is essential for thermoregulation,helping these animals maintain a constant body temperature despite the freezing external conditions.

(A-D) $(a) - T$: Epithelial tissue forms the outer covering and protective layers of the body.
$(b) - T$: These structures are lined by simple squamous or cuboidal epithelium for exchange and secretion.
$(c) - F$: Epithelial cells are tightly packed with almost no intercellular spaces.
$(d) - T$: The epithelial layer is permeable,allowing the exchange of substances.
$(e) - F$: The epithelial layer plays a crucial role in regulating the exchange of materials between the body and the external environment.

(N/A)

Voluntary muscles	Involuntary muscles
$(i)$ Their action is under our conscious control.	$(i)$ Their action is not under our conscious control.
$(ii)$ These are typically striated and multinucleate.	$(ii)$ These are typically non-striated and uninucleate.
$(iii)$ Example: Skeletal muscles (e.g.,biceps).	$(iii)$ Example: Smooth muscles (e.g.,muscles in the digestive tract).

(A) The classification of activities based on muscle type is as follows:
$(a)$ Jumping of a frog: This involves skeletal muscles which are under conscious control,hence it is Voluntary $(V)$.
$(b)$ Pumping of the heart: This is controlled by cardiac muscles which function automatically without conscious effort,hence it is Involuntary $(IV)$.
$(c)$ Writing with hand: This involves skeletal muscles controlled by the brain's conscious command,hence it is Voluntary $(V)$.
$(d)$ Movement of food in your intestine: This involves smooth muscles which perform peristalsis automatically,hence it is Involuntary $(IV)$.
Final Answer: $(a)-V, (b)-IV, (c)-V, (d)-IV$.

(N/A) The lining of blood vessels is made up of squamous epithelium,which allows for the easy transport of substances through diffusion.
$(b)$ The lining of the small intestine is made up of columnar epithelium,which facilitates absorption and secretion.
$(c)$ The lining of kidney tubules is made up of cuboidal epithelium,which provides mechanical support and helps in absorption and secretion.
$(d)$ Epithelial cells with cilia are found in the respiratory tract,where they help in moving mucus out of the airways.

(N/A) Epithelial tissues are the covering or protective tissues in the animal body. Epithelium covers most organs and cavities within the body and keeps different body systems separate. The skin,the lining of the mouth,the lining of blood vessels,lung alveoli,and kidney tubules are all made of epithelial tissue.
Epithelial tissue cells are tightly packed and form a continuous sheet. They have only a small amount of cementing material between them and almost no intercellular spaces. The permeability of the cells of various epithelia plays an important role in regulating the exchange of materials between the body and the external environment and also between different parts of the body. Regardless of the type,all epithelia are usually separated from the underlying tissue by an extracellular fibrous basement membrane.
Epithelial tissues are of the following types:
$(1)$ Simple squamous epithelium: Extremely thin and flat,forming a delicate lining. Found in blood vessels and lung alveoli where transportation occurs.
$(2)$ Stratified squamous epithelium: Arranged in many layers to prevent wear and tear. Found in the skin and lining of the mouth.
$(3)$ Columnar epithelium: Tall epithelial cells present where absorption and secretion occur,such as the inner lining of the intestine. If they have cilia,they are called ciliated columnar epithelium,which helps in moving mucus.
$(4)$ Cuboidal epithelium: Cube-shaped cells forming the lining of kidney tubules and ducts of salivary glands,providing mechanical support.
Additionally,some epithelial tissue folds inward to form a multicellular gland,known as glandular epithelium.

(N/A) The three main types of muscles found in the human body are as follows:
$1$. Striated Muscles (Skeletal Muscles): These are cylindrical,unbranched,and multinucleated. They show alternate light and dark bands (striations) and are attached to bones.
$2$. Smooth Muscles (Unstriated Muscles): These are spindle-shaped (fusiform) with a single central nucleus. They do not show striations and are found in the walls of internal organs like the stomach and intestines.
$3$. Cardiac Muscles: These are cylindrical,branched,and uninucleated. They show striations and are involuntary muscles found exclusively in the heart.
(Please refer to the provided image for the diagrams of these muscle types.)

(C) The muscular tissue whose cells are spindle-shaped and uninucleate is known as $Smooth$ $muscle$ (also called $Unstriated$ $muscle$ or $Involuntary$ $muscle$).
These cells are long with pointed ends (spindle-shaped) and contain a single central nucleus (uninucleate).
They are found in the walls of internal organs such as the stomach, intestines, and blood vessels.

(N/A) The solid matrix of cartilage is composed of proteins and sugars. These components are primarily organized as proteoglycans,which provide the tissue with its characteristic flexibility and strength.

(B) Adipose tissue is a type of connective tissue that stores fat. It is found below the skin and between internal organs. Due to the presence of fat,it acts as an insulator and prevents the loss of heat from the body,thereby helping to maintain body temperature.

(B) ligament is a specialized type of connective tissue that connects bone to bone. It is highly elastic and provides stability to joints.

(C) $WBC$ (White Blood Cells),also known as leukocytes,are an essential part of the immune system.
Their primary function is to defend the body against pathogens such as bacteria,viruses,and other foreign substances.
They achieve this by engulfing foreign particles or by producing antibodies,thereby providing immunity to the body.

(B) $RBCs$ (Red Blood Cells) contain a respiratory pigment called haemoglobin.
Haemoglobin binds with $O_{2}$ to form oxyhaemoglobin,which facilitates the transport of oxygen from the lungs to the body tissues.
It also plays a role in the transport of $CO_{2}$ from the tissues back to the lungs for exhalation.

(C) Blood platelets,also known as thrombocytes,are cell fragments derived from megakaryocytes in the bone marrow.
They play a crucial role in the process of blood clotting (coagulation) at the site of an injury to prevent excessive blood loss.

(B) Skeletal muscles are known as striated muscles because,when observed under a microscope,they exhibit a characteristic pattern of alternate light and dark bands or striations when stained appropriately. These bands are caused by the regular arrangement of contractile proteins,specifically actin and myosin,within the muscle fibers. Consequently,they are referred to as striated muscles.

(B) The connective tissue found between the skin and muscles is known as areolar connective tissue. It acts as a supporting and packing tissue between organs and fills the space inside the organs,supporting internal organs and helping in the repair of tissues.

(A) Simple squamous epithelial tissue consists of a single layer of extremely thin and flat cells,forming a delicate lining,such as in the blood vessels or lung alveoli.
Stratified squamous epithelial tissue consists of cells arranged in many layers to prevent wear and tear.
This multi-layered arrangement is specifically found in areas subjected to mechanical stress,such as the skin,the lining of the mouth,and the oesophagus.

(N/A) The muscular tissue present in the iris of the eye is the $Smooth$ muscle (also known as involuntary muscle).
These cells are $spindle-shaped$ (fusiform), meaning they are wide in the middle and tapered at both ends.

(N/A) $1$. Unstriated muscle fibres are found in the walls of the alimentary canal,iris of the eye,ureters,and bronchi.
$2$. Cuboidal epithelium is found in the lining of kidney tubules and ducts of salivary glands.
$3$. Adipose tissue is found below the skin and between internal organs.
$4$. Striated muscle fibres are found in the limbs,tongue,and body wall.

(N/A) The nervous tissue is primarily found in the following parts of the body:
$(i)$ Brain
$(ii)$ Spinal cord
$(iii)$ Nerves
The cells that make up the nervous tissue are called neurons (or nerve cells).

(N/A) Connective tissue is called so because its primary function is to bind,support,and connect different tissues and organs of the body together.
$(b)$ Areolar connective tissue fills the space inside the organs,supports internal organs,and helps in the repair of tissues.
$(c)$ Adipocytes contain fat globules. This stored fat acts as an insulator against heat loss and provides energy to the body.

(N/A) Features of cardiac muscles are:
$(i)$ These are involuntary muscles that exhibit rhythmic contraction and relaxation throughout life.
$(ii)$ These muscles are composed of non-tapering cells with faint cross-striations.
$(iii)$ The cells of these muscles are cylindrical,branched,and uninucleate.
$(iv)$ These muscles do not get fatigued under normal conditions.

(N/A) The two main components of blood are plasma and blood cells (corpuscles).
Blood is considered a type of connective tissue because it consists of a fluid matrix,known as plasma,in which various blood cells are suspended. Connective tissues are defined by having cells embedded in an extracellular matrix,and blood fits this definition as the plasma acts as the matrix connecting different parts of the body by transporting nutrients,gases,and waste products.

(N/A) The liquid matrix of the blood is called $Plasma$.
$Plasma$ contains water,proteins (such as $albumin$,$globulin$,and $fibrinogen$),salts (electrolytes),hormones,glucose,and waste products.
Two functions of blood are:
$1$. It transports respiratory gases ($O_2$ and $CO_2$) between the lungs and body tissues.
$2$. It transports digested food,hormones,and waste materials to different parts of the body.

(N/A)

Striated Muscles	Unstriated Muscles
$1.$ The cells are long,cylindrical,unbranched,and multinucleate.	$1.$ The cells are long,spindle-shaped (pointed at both ends),and uninucleate.
$2.$ These are mostly attached to bones and help in voluntary body movements.	$2.$ These are present in the walls of the alimentary canal,blood vessels,iris of the eye,ureters,and bronchi.

(N/A) Areolar tissue fills the space inside the organs,supports internal organs,and helps in the repair of tissues. (Any $1$)
$(b)$ Cuboidal epithelium provides mechanical support and is involved in secretion and absorption.