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Maharashtra SSC Physiology, Hygiene and Home Science (MSBSHSE) study materials
Maharashtra SSC Physiology, Hygiene and Home Science (MSBSHSE) study resources

Maharashtra SSC Physiology, Hygiene and Home Science (MSBSHSE) practice questions

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Question 1Human Physiology: Cells, Tissues and Organ Systems

Which cell organelle is described as the powerhouse of the cell because it releases energy through cellular respiration?

  1. Golgi body
  2. Mitochondrion Correct answer.
  3. Ribosome
  4. Lysosome

Explanation

Mitochondria carry out the later stages of aerobic respiration and transfer the released energy into ATP, which powers cell activities. This is why they are called the powerhouse of the cell. Ribosomes and Golgi bodies are concerned with protein handling, not bulk energy release.

Question 2Human Physiology: Cells, Tissues and Organ Systems

In a stained human cheek cell, which structure is seen as a dense body near the centre and controls the cell's activities?

  1. Plasma membrane
  2. Vacuole
  3. Nucleus Correct answer.
  4. Cell wall

Explanation

The nucleus is the dense, centrally placed body of the cheek cell and it directs cell activities through its genetic material. Human cheek cells are animal cells, so they have no cell wall. The vacuole is small and the plasma membrane is the outer boundary.

Question 3Human Physiology: Cells, Tissues and Organ Systems

Which tissue covers and protects the outer surface of the body and lines the internal cavities?

  1. Muscular tissue
  2. Epithelial tissue Correct answer.
  3. Nervous tissue
  4. Connective tissue

Explanation

Epithelial tissue forms continuous sheets of closely packed cells that cover surfaces and line cavities, acting as a protective and secretory layer. Muscular tissue produces movement and connective tissue joins and supports. Nervous tissue conducts impulses.

Question 4Human Physiology: Cells, Tissues and Organ Systems

Blood is classified as which type of tissue because its cells are separated by a large amount of fluid matrix?

  1. Nervous tissue
  2. Epithelial tissue
  3. Connective tissue Correct answer.
  4. Muscular tissue

Explanation

Blood is a connective tissue in which the cells float in an abundant liquid matrix called plasma. Connective tissues are defined by cells scattered in a prominent intercellular matrix. Its transport role does not change this classification.

Question 5Human Physiology: Cells, Tissues and Organ Systems

Which organ system is chiefly responsible for transporting oxygen, nutrients and waste products throughout the body?

  1. Circulatory system Correct answer.
  2. Excretory system
  3. Digestive system
  4. Respiratory system

Explanation

The circulatory system, with the heart, blood and blood vessels, carries oxygen, absorbed nutrients, hormones and wastes between organs. The respiratory system only exchanges gases in the lungs, while the digestive and excretory systems process food and remove wastes respectively.

Question 6Human Physiology: Cells, Tissues and Organ Systems

A student examines a tissue and finds elongated cells containing many parallel fibres that shorten when stimulated. Which tissue is this?

  1. Epithelial tissue
  2. Connective tissue
  3. Nervous tissue
  4. Muscular tissue Correct answer.

Explanation

Muscular tissue is made of elongated cells, or fibres, containing contractile proteins that shorten on stimulation to produce movement. Epithelial cells form sheets, nervous cells conduct impulses and connective cells are scattered in a matrix.

Question 7Human Physiology: Cells, Tissues and Organ Systems

The basic structural and functional unit of the human body is the:

  1. Organ system
  2. Cell Correct answer.
  3. Organ
  4. Tissue

Explanation

The cell is the smallest living unit that can carry out all life processes, so it is called the structural and functional unit of the body. Tissues, organs and organ systems are progressively larger levels built from cells.

Question 8Human Physiology: Cells, Tissues and Organ Systems

Which of the following is a function of nervous tissue in the human body?

  1. Storing fat as an energy reserve
  2. Carrying impulses between the brain and body parts Correct answer.
  3. Secreting digestive enzymes into the stomach
  4. Producing red blood cells in bone marrow

Explanation

Nervous tissue is made of neurons and supporting cells and its main function is to receive, conduct and transmit impulses. This allows coordination between the brain, spinal cord and body parts. Enzyme secretion, fat storage and blood cell formation belong to other tissues.

Question 9Human Physiology: Cells, Tissues and Organ Systems

A patient's blood report shows a low number of red blood cells. Which function of blood is most directly affected?

  1. Maintenance of body temperature
  2. Transport of oxygen to tissues Correct answer.
  3. Clotting at the site of a wound
  4. Defence against infection

Explanation

Red blood cells contain haemoglobin, which binds oxygen in the lungs and carries it to the tissues. A low red cell count therefore reduces oxygen transport most directly. Clotting depends on platelets, defence on white blood cells and temperature regulation on blood flow.

Question 10Human Physiology: Cells, Tissues and Organ Systems

Which sequence correctly shows the increasing level of organisation in the human body?

  1. Organ system, organ, cell, tissue
  2. Cell, tissue, organ, organ system Correct answer.
  3. Organ, cell, tissue, organ system
  4. Tissue, cell, organ system, organ

Explanation

Body organisation rises from the cell to tissues of similar cells, then to organs made of several tissues, and finally to organ systems made of cooperating organs. The correct order is therefore cell, tissue, organ, organ system. Any sequence that places a larger level before a smaller one is incorrect.

Question 11Human Physiology: Cells, Tissues and Organ Systems

Bone and cartilage are grouped as skeletal connective tissue mainly because they:

  1. contain contractile protein fibres that shorten
  2. line body cavities and secrete mucus
  3. conduct electrical impulses to muscles
  4. form a firm matrix that supports and protects body parts Correct answer.

Explanation

Skeletal connective tissues such as bone and cartilage have a firm, hard or flexible matrix that gives support and protection to softer body parts. Their cells are widely spaced within this matrix. Contractile fibres, lining sheets and impulse conduction are features of other tissues.

Question 12Human Physiology: Cells, Tissues and Organ Systems

Which organ system removes urea and excess salts from the blood and regulates water balance?

  1. Endocrine system
  2. Digestive system
  3. Excretory system Correct answer.
  4. Respiratory system

Explanation

The excretory system, mainly through the kidneys, filters the blood to remove urea and excess salts and adjusts water loss in urine. This maintains the internal environment. The digestive, respiratory and endocrine systems have different primary roles.

Question 13Human Physiology: Cells, Tissues and Organ Systems

A sample of tissue shows flat cells arranged in a single continuous layer with very little space between them. This arrangement is best suited for:

  1. storing fat as an energy reserve
  2. contracting to move bones
  3. conducting impulses over long distances
  4. forming a protective covering and lining Correct answer.

Explanation

Flat cells packed tightly in a continuous sheet form a protective covering that lines surfaces and prevents friction and injury. This is the typical arrangement of squamous epithelium. Storage, conduction and contraction require quite different cell shapes and arrangements.

Question 14Human Physiology: Cells, Tissues and Organ Systems

Which part of a neuron carries impulses away from the cell body towards the next cell?

  1. Axon Correct answer.
  2. Nucleus
  3. Cell membrane
  4. Dendrite

Explanation

The axon is the long single process of a neuron that conducts impulses away from the cell body towards another neuron or an effector. Dendrites bring impulses towards the cell body. The nucleus and cell membrane are general cell parts and do not serve this conducting role.

Question 15Human Physiology: Cells, Tissues and Organ Systems

A person suffers a burn that destroys the outer epithelial layer of the skin. Which function of the skin is lost first at that site?

  1. Storage of bile
  2. Absorption of digested food
  3. Protection against entry of germs Correct answer.
  4. Production of urine

Explanation

The outer epithelial layer of the skin forms a continuous protective barrier against germs and injury. When it is destroyed, this barrier is lost and infection risk rises. Urine production, bile storage and food absorption occur in other organs.

Question 16Human Physiology: Cells, Tissues and Organ Systems

Which statement correctly distinguishes an organ from a tissue?

  1. An organ is made of two or more tissues working together, while a tissue is a group of similar cells. Correct answer.
  2. An organ is a group of similar cells, while a tissue is a group of organs.
  3. Both an organ and a tissue are made of identical cells with the same function.
  4. A tissue contains organ systems, while an organ contains only one type of cell.

Explanation

A tissue is a group of similar cells specialised for a particular function, whereas an organ is formed of two or more different tissues arranged to perform a common task. For example, the stomach contains epithelial, muscular, nervous and connective tissue. The other statements reverse or confuse these definitions.

Question 17Human Physiology: Cells, Tissues and Organ Systems

Which feature is common to human red blood cells and nerve cells?

  1. Both contain chloroplasts for photosynthesis
  2. Both contain a large nucleus throughout their life
  3. Both are surrounded by a plasma membrane and contain cytoplasm Correct answer.
  4. Both have a rigid cellulose cell wall

Explanation

All human cells, including red blood cells and nerve cells, share a plasma membrane enclosing cytoplasm. Mature red blood cells lose their nucleus, and no human cell has a cellulose wall or chloroplasts. The shared feature is therefore the basic cell boundary and cytoplasm.

Question 18Human Physiology: Cells, Tissues and Organ Systems

Smooth muscle differs from skeletal muscle in that smooth muscle:

  1. is found only in the heart and beats rhythmically
  2. contains no contractile proteins and cannot shorten
  3. is attached to bones and moves the skeleton
  4. is found in the walls of internal organs and works without conscious control Correct answer.

Explanation

Smooth muscle occurs in the walls of organs such as the stomach, intestine and blood vessels and contracts involuntarily. Skeletal muscle is attached to bones and works under conscious control, while cardiac muscle is the special striated muscle of the heart.

Question 19Human Physiology: Cells, Tissues and Organ Systems

Which organ system provides the body's first line of defence through an intact skin surface and mucous membranes?

  1. Integumentary system Correct answer.
  2. Skeletal system
  3. Endocrine system
  4. Lymphatic system

Explanation

The integumentary system, mainly the skin with its epithelial covering and mucous membranes at body openings, forms a physical barrier that keeps germs out. The skeletal system supports the body and the endocrine system secretes hormones. The lymphatic system acts after germs have entered.

Question 20Human Physiology: Cells, Tissues and Organ Systems

A tissue sample contains cells with a large amount of stored fat, few organelles and a thin rim of cytoplasm. This tissue most likely functions to:

  1. insulate the body and store energy Correct answer.
  2. conduct impulses to the brain
  3. produce movement by contraction
  4. secrete hormones into the blood

Explanation

Cells dominated by a large fat droplet with little cytoplasm are adipocytes of adipose connective tissue. This tissue stores energy and provides insulation and padding around organs. Conduction, hormone secretion and contraction are functions of other tissues.

Question 21Human Physiology: Cells, Tissues and Organ Systems

In the wall of the small intestine, epithelial, muscular, nervous and connective tissues work together. This illustrates that the intestine is:

  1. an organ system made of many organs
  2. a tissue made of similar cells
  3. an organ formed of several tissues Correct answer.
  4. a single specialised cell

Explanation

An organ is defined as a structure made of two or more different tissues that cooperate for a common function. The small intestine contains epithelium for absorption, muscle for movement, nerve tissue for coordination and connective tissue for support. It is therefore an organ, not a cell, tissue or organ system.

Question 22Human Physiology: Cells, Tissues and Organ Systems

A person with a disorder of the cardiac muscle would most directly affect which function?

  1. Secretion of insulin to control blood sugar
  2. Rhythmic pumping of blood through the circulatory system Correct answer.
  3. Exchange of gases across the alveoli
  4. Filtration of urea from the blood

Explanation

Cardiac muscle forms the wall of the heart, and its rhythmic contraction pumps blood through the vessels. Urea filtration belongs to the kidneys, insulin secretion to the pancreas and gas exchange to the lungs. Only the pumping action depends directly on cardiac muscle.

Question 23Human Physiology: Cells, Tissues and Organ Systems

Which comparison of the three muscle types is correct?

  1. Cardiac muscle is striated and involuntary, while smooth muscle is unstriated and involuntary. Correct answer.
  2. Skeletal muscle is involuntary and unstriated, while smooth muscle is voluntary and striated.
  3. All three muscle types are voluntary and show cross-striations.
  4. Smooth muscle is striated and voluntary, while cardiac muscle is unstriated and voluntary.

Explanation

Cardiac muscle shows cross-striations but works involuntarily, and smooth muscle lacks striations and is also involuntary. Skeletal muscle alone is striated and voluntary. This makes the second comparison the only accurate one.

Question 24Human Physiology: Cells, Tissues and Organ Systems

A laboratory technician examines a tissue and notes scattered cells lying in a large amount of hard matrix containing calcium salts. This tissue is best identified as:

  1. cardiac muscle
  2. bone Correct answer.
  3. nervous tissue
  4. squamous epithelium

Explanation

Bone is a connective tissue whose cells lie in a hard matrix hardened by calcium salts, giving the skeleton its strength. Epithelium has closely packed cells, cardiac muscle has striated fibres and nervous tissue has conducting cells. The hard calcified matrix is the decisive feature.

Question 25Human Physiology: Cells, Tissues and Organ Systems

Which statement best explains why the cell is called the functional unit of the body?

  1. Because all cells in the body are identical in shape and function
  2. Because cells are the largest structures visible in the body
  3. Because every life process of the body is ultimately carried out within cells Correct answer.
  4. Because cells can survive independently of the body

Explanation

The cell is the functional unit because the chemical reactions of life, such as respiration, synthesis and excretion, take place within cells. Tissues and organs perform their roles only through the activity of their cells. Cells differ greatly in shape and function, and most human cells cannot live independently.

Question 26Human Physiology: Cells, Tissues and Organ Systems

A student views a tissue under a microscope and sees a single layer of flat cells resting on a basement membrane, with no blood vessels running through the cell layer itself. Which tissue type is this?

  1. Areolar connective tissue
  2. Simple squamous epithelium Correct answer.
  3. Stratified columnar epithelium
  4. Non-striated muscle tissue

Explanation

Epithelial tissue is described by the number of cell layers and the shape of the surface cells, so one layer of flattened cells is simple squamous epithelium. Such sheets line surfaces such as the alveoli and the inner lining of blood vessels, where thinness aids exchange. The absence of vessels within the layer fits epithelium, which is avascular and fed by diffusion from underlying connective tissue.

Question 27Human Physiology: Cells, Tissues and Organ Systems

Why is a neuron's axon able to conduct an impulse rapidly over a long distance, while the dendrites mainly receive information?

  1. Dendrites are myelinated while axons are always unmyelinated
  2. Dendrites contain more cytoplasm than the axon and so conduct faster
  3. The axon is a single long process that carries the impulse away from the cell body Correct answer.
  4. The axon has many short branches that collect stimuli from the environment

Explanation

A neuron typically has one axon, a long process that transmits impulses away from the cell body towards the next cell or effector. Dendrites are short branched processes that bring impulses towards the cell body. Speed along the axon is further increased where a myelin sheath is present, which insulates the fibre and allows saltatory conduction.

Question 28Human Physiology: Cells, Tissues and Organ Systems

A blood sample is examined and the plasma is found to be deficient in fibrinogen. Which process will be most directly impaired?

  1. Clotting of blood at the site of a wound Correct answer.
  2. Transport of oxygen by haemoglobin
  3. Maintenance of osmotic balance by plasma proteins
  4. Defence against invading bacteria

Explanation

Fibrinogen is a plasma protein that is converted into fibrin threads during clotting, forming the mesh that traps blood cells and seals a wound. Without adequate fibrinogen, the coagulation mechanism cannot build this mesh. Osmotic balance is chiefly the work of albumin, oxygen transport depends on haemoglobin inside red cells, and defence depends on white cells and antibodies.

Question 29Human Physiology: Cells, Tissues and Organ Systems

In the hierarchy of body organisation, which level lies immediately between a tissue and an organ system?

  1. Cell
  2. Organism
  3. Organelle
  4. Organ Correct answer.

Explanation

The accepted order is cell, tissue, organ, organ system and organism. An organ is made of two or more tissues working together for a particular function, and several organs that cooperate form an organ system. Cells and organelles lie below tissue level, and the organism is the highest level.

Question 30Human Physiology: Cells, Tissues and Organ Systems

A long bone such as the femur is strong yet not brittle because of which feature of skeletal connective tissue?

  1. A soft matrix containing abundant fat cells and few mineral salts
  2. A matrix made mainly of elastic fibres with very little mineral matter
  3. A hard matrix containing calcium salts together with flexible collagen fibres Correct answer.
  4. A liquid matrix that circulates through channels within the bone

Explanation

Bone matrix is impregnated with calcium and phosphate salts, which give hardness and resistance to compression. Collagen fibres embedded in the same matrix provide tensile strength and slight flexibility, so the bone resists both crushing and snapping. This combination of mineral hardness and protein fibre toughness is what makes skeletal tissue strong without being brittle.

Question 31Human Physiology: Cells, Tissues and Organ Systems

Which organ system is chiefly responsible for exchanging oxygen and carbon dioxide between the body and the outside air?

  1. Digestive system
  2. Respiratory system Correct answer.
  3. Circulatory system
  4. Excretory system

Explanation

The respiratory system, through the lungs and their alveoli, brings air into close contact with blood so that oxygen enters and carbon dioxide leaves the body. The circulatory system only transports these gases between the lungs and the tissues. Digestion absorbs nutrients, and excretion removes nitrogenous wastes and regulates water and salts.

Question 32Human Physiology: Cells, Tissues and Organ Systems

A person's skin suffers extensive damage over a large area, yet the underlying muscles and bones remain intact. Which body function is most immediately threatened by the loss of the skin barrier?

  1. Protection against entry of disease-causing microbes Correct answer.
  2. Production of bile for fat digestion
  3. Filtration of urea from the blood
  4. Exchange of oxygen across the alveolar surface

Explanation

Intact skin is the body's first line of defence, forming a continuous physical barrier that keeps microbes out. When a large area of skin is lost, this barrier is broken and the risk of infection rises sharply, along with loss of water and heat. Bile production belongs to the liver, gas exchange to the lungs, and urea filtration to the kidneys.

Question 33Human Physiology: Cells, Tissues and Organ Systems

Which feature is shared by a human red blood cell and a mature nerve cell?

  1. Both possess a nucleus throughout their working life
  2. Both are surrounded by a plasma membrane and contain cytoplasm Correct answer.
  3. Both contain haemoglobin for carrying oxygen
  4. Both are capable of generating and conducting electrical impulses

Explanation

Every living cell of the human body, however specialised, is bounded by a plasma membrane enclosing cytoplasm with organelles. Red blood cells and nerve cells differ greatly in shape and function but share this basic cell plan. Only nerve cells conduct impulses, and only red cells contain haemoglobin.

Question 34Human Physiology: Cells, Tissues and Organ Systems

Cardiac muscle differs from skeletal muscle in which respect?

  1. Cardiac muscle is striated and contracts involuntarily without fatigue Correct answer.
  2. Cardiac muscle is smooth and contracts only under conscious control
  3. Cardiac muscle consists of spindle-shaped cells with a single central nucleus and no striations
  4. Cardiac muscle is non-striated and is attached to bones by tendons

Explanation

Cardiac muscle shows faint striations like skeletal muscle but works involuntarily and rhythmically throughout life without tiring. Its branched fibres are joined by intercalated discs that let impulses spread quickly through the heart wall. Skeletal muscle is striated but voluntary and attached to bones, while smooth muscle is non-striated and spindle-shaped.

Question 35Human Physiology: Cells, Tissues and Organ Systems

A tissue sample shows scattered cells lying in a large amount of hard matrix containing calcium salts, with the cells occupying small spaces within the matrix. Which tissue is this?

  1. Adipose tissue
  2. Hyaline cartilage
  3. Dense fibrous connective tissue
  4. Bone Correct answer.

Explanation

Bone is a connective tissue in which cells sit in small cavities called lacunae within a hard matrix heavily impregnated with calcium salts. This mineralised matrix gives bone its rigidity and its role in support and protection. Cartilage has a firm but flexible matrix without such heavy calcification, and adipose and fibrous tissues have soft matrices.

Question 36Human Physiology: Cells, Tissues and Organ Systems

The wall of the small intestine contains epithelium for absorption, smooth muscle for peristalsis, nerve tissue for coordinating movement and connective tissue for support. This arrangement best illustrates which concept?

  1. A single tissue performing several unrelated functions
  2. An organ system made of identical organs
  3. A cell specialised for absorption alone
  4. An organ formed by different tissues cooperating for one function Correct answer.

Explanation

The small intestine is an organ, and its wall is built from several tissues that each contribute a part of the organ's overall job of digesting and absorbing food. Epithelium absorbs, muscle moves, nerve tissue coordinates and connective tissue supports, so the tissues cooperate rather than act alone. This cooperation of different tissues is the defining feature of an organ.

Question 37Human Physiology: Cells, Tissues and Organ Systems

Which organ system is the first line of defence because its intact surface and mucous membranes prevent microbes from entering the body?

  1. The skeletal system, including bones and joints
  2. The lymphatic system, including lymph nodes and vessels
  3. The endocrine system, including glands and hormones
  4. The integumentary system, including the skin and mucous membranes Correct answer.

Explanation

The integumentary system, chiefly the skin with its mucous membranes at body openings, provides a continuous physical barrier that blocks the entry of microbes. Sebum and mucus add chemical protection. The skeletal system supports and protects internal organs but does not form the body's outer barrier, and the endocrine and lymphatic systems act after or alongside this first defence.

Question 38Human Physiology: Cells, Tissues and Organ Systems

Which function of blood is most directly reduced when the number of red blood cells falls?

  1. Transport of oxygen from the lungs to the tissues Correct answer.
  2. Production of antibodies against infection
  3. Clotting at the site of an injury
  4. Maintenance of body temperature by vasoconstriction

Explanation

Red blood cells contain haemoglobin, which binds oxygen in the lungs and releases it in the tissues, so a fall in their number lowers the blood's oxygen-carrying capacity. Clotting depends on platelets and plasma clotting factors, while antibodies come from white cells. Temperature regulation involves blood flow and vessel diameter rather than the oxygen-carrying pigment.

Question 39Human Physiology: Cells, Tissues and Organ Systems

A gland releases its secretion through a duct onto an epithelial surface rather than into the bloodstream. Which type of gland is this, and which example fits?

  1. An exocrine gland, such as the salivary gland Correct answer.
  2. An endocrine gland, such as the adrenal gland
  3. An endocrine gland, such as the thyroid gland
  4. An exocrine gland, such as the pituitary gland

Explanation

Exocrine glands keep a duct and pour their secretion onto a surface or into a cavity, as the salivary glands deliver saliva into the mouth. Endocrine glands have no ducts and release hormones directly into the blood, so the thyroid, adrenal and pituitary glands are endocrine. The presence or absence of a duct is the deciding feature.

Question 40Human Physiology: Cells, Tissues and Organ Systems

Blood flows from the heart to the lungs and back to the heart before being pumped to the rest of the body. Which statement about this arrangement is correct?

  1. The systemic circuit carries deoxygenated blood to the body tissues and returns oxygenated blood
  2. Both circuits carry blood of the same oxygen content throughout
  3. The right side of the heart handles oxygenated blood while the left handles deoxygenated blood
  4. The pulmonary circuit carries deoxygenated blood to the lungs and returns oxygenated blood to the heart Correct answer.

Explanation

In the pulmonary circuit the right side of the heart pumps deoxygenated blood to the lungs, where gas exchange occurs, and oxygenated blood returns to the left side. The left side then pumps this oxygenated blood through the systemic circuit to the body, and deoxygenated blood returns to the right side. This double circulation keeps oxygenated and deoxygenated blood largely separate.

Question 41Human Physiology: Cells, Tissues and Organ Systems

A student observes a tissue in which cells are separated by large amounts of fluid, and the cells are not attached to a basement membrane. Which tissue type is this most likely to be?

  1. Nervous tissue
  2. Connective tissue Correct answer.
  3. Muscular tissue
  4. Epithelial tissue

Explanation

Connective tissue is characterised by cells that are widely spaced and embedded in an abundant intercellular matrix, which may be fluid, gel-like, or hard. Epithelial tissue, in contrast, consists of closely packed cells resting on a basement membrane. Therefore, the description matches connective tissue.

Question 42Human Physiology: Cells, Tissues and Organ Systems

A patient's blood report shows a low platelet count. Which physiological process is most directly at risk?

  1. Regulation of body temperature
  2. Clotting of blood Correct answer.
  3. Production of antibodies
  4. Transport of oxygen

Explanation

Platelets are cell fragments that adhere to damaged blood vessel walls and release factors that initiate the clotting cascade. A reduced platelet count therefore impairs haemostasis and increases the risk of bleeding. Oxygen transport depends on red blood cells, antibodies are produced by lymphocytes, and temperature regulation involves blood flow and sweat glands.

Question 43Human Physiology: Cells, Tissues and Organ Systems

During strenuous exercise, skeletal muscle fibres contract repeatedly and require a continuous supply of energy. Which structural feature of skeletal muscle best supports this high energy demand?

  1. Multiple nuclei per fibre
  2. Abundant mitochondria Correct answer.
  3. Branching of fibres
  4. Presence of intercalated discs

Explanation

Skeletal muscle fibres are rich in mitochondria, which carry out aerobic respiration to produce ATP for contraction. The abundance of mitochondria allows sustained energy production during repeated contractions. Intercalated discs and branching are features of cardiac muscle, and multiple nuclei are common in skeletal muscle but do not directly meet the energy demand.

Question 44Human Physiology: Cells, Tissues and Organ Systems

A person suffers a stroke that damages a region of the brain. As a result, the person loses the ability to consciously control voluntary movements on one side of the body. Which part of the nervous system is most likely damaged?

  1. Cerebrum Correct answer.
  2. Cerebellum
  3. Hypothalamus
  4. Medulla oblongata

Explanation

The cerebrum contains the motor areas that initiate voluntary movements, with the left hemisphere controlling the right side of the body and vice versa. Damage to these areas causes loss of conscious voluntary control. The cerebellum coordinates balance and fine movement, the medulla controls involuntary vital reflexes, and the hypothalamus regulates homeostasis.

Question 45Nutrition, Digestion and Metabolism

In the study of balanced diets, which nutrient group is the body's most concentrated source of energy, supplying about 9 kcal per gram?

  1. Dietary fibre
  2. Fats Correct answer.
  3. Carbohydrates
  4. Proteins

Explanation

Fats yield roughly 9 kcal per gram, whereas carbohydrates and proteins each provide about 4 kcal per gram. Because fat is energy-dense, it is the most concentrated fuel in the diet. Fibre contributes little usable energy because humans cannot digest it.

Question 46Nutrition, Digestion and Metabolism

A student's diet lacks fresh citrus fruits and amla, and he develops bleeding gums and slow wound healing. Which vitamin deficiency best explains these signs?

  1. Vitamin K
  2. Vitamin C Correct answer.
  3. Vitamin D
  4. Vitamin A

Explanation

Vitamin C (ascorbic acid) is needed for collagen synthesis, so its deficiency causes scurvy with bleeding gums and poor wound healing. Citrus fruits and amla are classic rich sources. The other vitamins listed produce different deficiency patterns.

Question 47Nutrition, Digestion and Metabolism

Which enzyme secreted in the mouth begins the chemical digestion of cooked starch?

  1. Pepsin
  2. Lipase
  3. Salivary amylase Correct answer.
  4. Trypsin

Explanation

Salivary amylase (ptyalin) hydrolyses starch into maltose in the slightly alkaline mouth. Pepsin and trypsin act on proteins in the stomach and small intestine respectively. Lingual lipase acts on fats, not starch.

Question 48Nutrition, Digestion and Metabolism

Which mineral is essential for the formation of haemoglobin, and whose deficiency causes anaemia?

  1. Iodine
  2. Iron Correct answer.
  3. Sodium
  4. Calcium

Explanation

Iron is a structural component of the haem part of haemoglobin, so iron deficiency produces microcytic anaemia. Calcium supports bone and clotting, iodine supports thyroid hormone, and sodium maintains fluid balance.

Question 49Nutrition, Digestion and Metabolism

The finger-like projections of the small intestine that greatly increase the surface area for absorption are called:

  1. Rugae
  2. Alveoli
  3. Villi Correct answer.
  4. Nephrons

Explanation

Villi are microscopic projections of the intestinal mucosa containing blood capillaries and a lacteal. They multiply the absorptive surface many times over. Rugae are gastric folds, alveoli are lung sacs, and nephrons are kidney units.

Question 50Nutrition, Digestion and Metabolism

In the small intestine, bile salts assist digestion by:

  1. Splitting fats into fatty acids and glycerol
  2. Converting starch into maltose
  3. Breaking proteins into amino acids
  4. Emulsifying fats into tiny droplets Correct answer.

Explanation

Bile salts emulsify large fat globules into fine droplets, increasing the surface area on which pancreatic lipase can act. Bile itself contains no fat-splitting enzyme. Protein and starch digestion depend on other enzymes.