Human Anatomy and Physiology is part of Biology. Below are notes on 11 sub-topics, followed by practice MCQs from State PSC and UPSC papers.

Cellular and Tissue Organization

  • Levels of Organization:
    • Biological Hierarchy: Atom → Molecule (e.g., Protein) → Cell → Tissue → Organ → Organ System → Organism.
    • Tissue: A group of similar cells (structure & function) specialized to perform a specific function.
  • Elemental Composition & Water Content (Adult Human Body by Mass):
    • Most Abundant Elements: Oxygen (approx. 65%) > Carbon (approx. 18-19%) > Hydrogen (approx. 9-10%) > Nitrogen (approx. 3%).
    • Water Percentage: Approximately 65%.
  • Types of Animal Tissues:
    • 1. Epithelial Tissue: Forms protective linings and coverings.
      • Squamous Epithelium: Thin, flat cells.
      • Location: Inner lining of mouth, oesophagus, skin (outer layer, stratified), blood vessel lining, lung alveoli.
      • NOT found in: Kidney tubules, ducts of salivary glands.
      • Cuboidal Epithelium: Cubeshaped cells.
      • Location: Lining of kidney tubules, ducts of salivary glands.
      • Columnar Epithelium: Columnshaped cells.
      • Location: Lining of small intestine.
    • 2. Connective Tissue: Supports, connects, binds, or separates other tissues and organs.
      • Examples: Blood, Bone, Cartilage, Ligaments, Tendons, Adipose tissue, Areolar tissue.
      • NOT a Connective Tissue: Smooth muscle (it's a muscle tissue).
      • Adipose Tissue:
      • Cells: Adipocytes (fat cells).
      • Function: Stores, synthesizes, and metabolizes fat. Acts as a thermal insulator.
      • Location: Under the skin, around internal organs.
      • Blood: Fluid connective tissue. (Reticulocytes are immature red blood cells).
      • Cartilage: Formed by Chondrocytes.
      • Bone: Formed by Osteocytes.
    • 3. Muscle Tissue: Responsible for movement.
      • Types: Smooth muscle, Striated (Skeletal) muscle, Cardiac muscle.
    • 4. Nervous Tissue: Transmits nerve impulses.
  • Vestigial Structures in Humans:
    • Examples: Vermiform appendix, Nictitating membrane (plica semilunaris), Tail vertebrae (coccyx).
    • NOT Vestigial: Nails.

Circulatory System and Lymphatic System

  • Blood: A specialized fluid connective tissue.
  • Hemoglobin: Oxygen-binding protein in red blood cells; contains iron (Fe) in its heme group.
  • Myoglobin: Oxygen-binding protein in muscle tissue; contains iron (Fe) in its heme group; structurally a monomer (single polypeptide chain).
  • Other oxygen-binding proteins: Hemerythrin (found in some invertebrates).
  • Snake Venom: Can be hemotoxic (primarily affects blood/circulatory system, causing bleeding and tissue damage) or neurotoxic (primarily affects the nervous system, leading to paralysis).
  • Jarvik-7: The first successful permanent artificial heart.

Digestive System

  • Liver: Largest gland in the human body.
  • Liver: Primary site for detoxification of toxic compounds (e.g., alcohol, methanol).
  • Methanol toxicity: Methanol is oxidized to methanal (formaldehyde) in the liver, which coagulates protoplasm.
  • Detoxification of alcohol (methyl and ethyl) in the body occurs via oxidation in the liver.
  • Liver (and muscles): Primarily store carbohydrates in the form of glycogen.
  • Liver cells: Smooth endoplasmic reticulum (SER) plays a crucial role in detoxification.
  • Liver: Contains Kupffer cells (specialized macrophages).
  • Hepatomegaly: Term associated with the enlargement of the liver.
  • Liver: Organ most affected on keeping fast for a long time due to its central metabolic role.
  • Ptyalin (salivary amylase): Digests starch.
  • Pepsin: Digests proteins.
  • Renin (kidney-derived): Converts angiotensinogen in blood into angiotensin.
  • Cholesterol: Is a steroid.
  • Endoscope: Used to diagnose diseases of inner parts of the human body.
  • Kidney: Is an organ, not primarily classified as a gland (unlike liver, pancreas).
  • Human dental formula (for each half of upper/lower jaw, Incisor, Canine, Premolar, Molar): 2123/2123.
  • Vestigial organs in humans: Appendix, wisdom tooth, tailbone (coccyx).
  • Diaphragm: Is NOT a vestigial organ.

Homeostasis and Regulatory Mechanisms

  • Human body contains about 70% water.
  • Homeostasis is the ability of an organism to maintain internal stability and equilibrium of its internal body environment.
  • Blood pH (~7.4) is maintained by buffer systems, primarily the bicarbonate buffer system (H₂CO₃ and NaHCO₃).
  • Sodium (Na) and Potassium (K) are crucial elements involved in the control of blood water content and acid-base balance.
  • Inside vertebrate cells and tissues, there is a high concentration of K⁺ ions and a low concentration of Na⁺ ions.
  • Excess glucose is stored in the human body as glycogen, primarily in the liver and muscles.
  • Blood glucose level is commonly expressed in milligrams per decilitre (mg/dL).
  • A subnormal concentration of calcium ions (hypocalcemia) in the blood can cause severe symptoms like twitching, convulsions, unconsciousness, and death.
  • Warm-blooded (homeothermic) animals, such as hens, tigers, and bats, are able to keep their body temperature constant. Toad (an amphibian) is not warm-blooded.
  • The most important function of perspiration (sweating) is to regulate body temperature through evaporative cooling.
  • High humidity combined with heat makes humans feel unpleasant because sweat does not evaporate effectively.
  • Aestivation (summer dormancy) is seen in amphibians (e.g., frogs) and some mammals (e.g., squirrels) as an adaptation to heat and drought.
  • A circadian rhythm is an endogenous biological process with a periodicity of approximately 24 hours, regulated by the biological clock.
  • Human sleep and awake phases are examples of circadian rhythms; heart-beat is not.
  • Kangaroo rats can live the longest duration without drinking water, relying on metabolic water.
  • Camels adapt to desert conditions due to:
    • Humps with stored food as fats (for metabolic water and energy).
    • Ability to maintain blood plasma volume.
    • Hair growth near eyes and nostrils for protection and moisture retention.
  • If a healthy freshwater fish is placed in saltwater, it becomes dehydrated and dies due to osmosis (water loss from body to hypertonic environment).
  • Osmoconformers are marine animals that maintain their internal body fluid osmolarity consistent with the ambient seawater; an example is the Hagfish.
  • Lethal blood alcohol concentration in hu‐

definitively lethal.

  • Anesthetizing/sedating fish before transport aims to reduce stress, oxygen consumption, excitement, injury, and handling time. Undesired outcomes include increased revival time, mortality during revival, or high postsedation effects.
  • MRI stands for Magnetic Resonance Imaging.
  • SATYAM (Science and Technology of Yoga and Meditation) is a program under the Department of Science and Technology that conducts scientific research on the effects of yoga and meditation on physical and mental health.

Immune System

  • White Blood Cells (WBCs) / Leukocytes are the primary cells of the immune system.
  • Lymphocytes are the most important cell type associated with body immunity, responsible for specific immune responses and antibody production.
  • Antigen is a substance (foreign) that stimulates the immune system to produce antibodies.
  • Antibody (Immunoglobulin - Ig) is a protein produced by plasma cells (differentiated B lymphocytes) in response to an antigen. Immunoglobulins are proteins.
  • The strength of binding between an antigen and an antibody is known as Affinity.
  • Primary Lymphoid Organs: Bone marrow (site of origin for all blood cells, B-lymphocyte maturation) and Thymus (T-lymphocyte maturation).
  • Secondary Lymphoid Organs: Spleen, lymph nodes, tonsils, Peyer's patches, appendix.
  • Pancreas is not considered an immunologically important organ.
  • Innate Immunity is non-specific and present from birth. It includes:
    • Physical barriers: Skin, mucous membranes.
    • Physiological barriers: Stomach acid, saliva, tears (contain Lysozyme, an antibacterial enzyme).
    • Cellular barriers: Phagocytic cells like Neutrophils and Macrophages.
  • Acquired (Adaptive) Immunity is specific, has memory, and develops after exposure to pathogens.
  • Types of Acquired Immunity:
    • Natural Active Immunity: Acquired after a natural infection (e.g., developing immunity after smallpox infection).
    • Natural Passive Immunity: Transferred from mother to child (e.g., via placenta - IgG; via breast milk/colostrum IgA).
    • Artificial Active Immunity: Developed due to vaccination (introduction of antigens).
    • Artificial Passive Immunity: Acquired by direct transfer of pre-formed antibodies (e.g., anti-rabies serum).
  • Colostrum is the special yellowish milk produced by a lactating mother during the initial days of lactation; it is essential for newborn immunity as it contains abundant antibodies, primarily Immunoglobulin A (IgA).
  • Immunoglobulin A (IgA) is found in secretions like breast milk, colostrum, tears, saliva, and mucous.
  • Lymphocytes are the cells that produce antibodies against foreign antigens. (Specifically, B lymphocytes differentiate into plasma cells to produce antibodies).

Integumentary System

  • Skin is the largest organ in the human body.
  • The outermost layer of the skin is called Epidermis.
  • Subcutaneous fat (adipose tissue) located below the skin surface acts as a thermal insulator, preventing loss of heat from the body.
  • Melanin is a natural pigment that provides color to skin, hair, and iris, and offers protection against Ultraviolet (UV) radiation.
  • Alpha-keratin is a fibrous structural protein present in skin, hair, nails, and wool.
  • Mammary glands are modified sweat glands (specifically, modified apocrine sweat glands).
  • Fluoride helps harden the enamel of teeth.
  • Conventional earlobe piercing often does not lead to significant bleeding due to the lesser blood supply in the cartilage of the earlobe compared to other body parts.
  • Exposure to blue light may accelerate skin aging.

Muscular System

  • Muscular tissue is specialized for contraction and relaxation, enabling movement.
  • During intense physical activity (e.g., sprinting), when oxygen supply is insufficient, muscle cells perform anaerobic respiration.
  • In anaerobic respiration, glucose is broken down to produce energy and lactic acid.
  • Accumulation of lactic acid in muscle fibers leads to muscle fatigue and cramps.
  • Lactic acid formation provides additional energy from glucose in the absence of sufficient oxygen during strenuous exercise.

Nervous System and Sensory Organs

  • The sensitive area of the human tongue to bitterness is the posterior part.
  • Myopia (near-sightedness) is a vision defect where a person can see near objects clearly but distant objects unclearly.
  • Possible reasons for Myopia include excessive curvature of the eye lens and/or elongation of the eye-ball.
  • Myopia is corrected using concave lenses.
  • Presbyopia usually develops with ageing.
  • Persons with Presbyopia wear either bi-focal lenses (consisting of both concave and convex lenses) or progressive lenses.
  • A colour-blind person most commonly cannot differentiate between red and green colours.
  • The human eye forms the image of an object on its Retina.
  • The change of focal length of an eye lens (accommodation) is caused by the action of the Ciliary muscles.
  • The eye lens forms an Inverted and Real image of an object on the retina.
  • In eye donation, the Cornea of the donor's eye is utilized/transplanted.
  • Colour vision in human eyes is the function of photoreceptor cells named Cones. Rods are responsible for dim light vision.
  • Bats detect obstacles and navigate using Echolocation, by receiving reflected Ultrasonic waves.
  • Light enters the eye through a thin membrane called the Cornea.
  • Cornea is composed of proteins and cells and is avascular.
  • The ability of the human eye to focus on objects at different distances by adjusting the focal length of the eye lens is called Accommodation.
  • The Cochlea, located in the inner ear, converts the pressure variations of sound waves to electrical signals.
  • An Ophthalmologist deals with Eyes.
  • Myopia is technically termed as Nearsightedness.
  • Audiogram is for testing Ear/hearing.
  • ECG (Electrocardiogram) is for the Heart.
  • EEG (Electroencephalogram) is for the Brain.
  • Mammogram is for the Breast.
  • The principal reason for having two eyes (binocular vision) is to enhance Depth perception.
  • Voices of men and women are different because the length and thickness of their vocal cords differ.
  • Movement of food in the digestive system (peristalsis) is involuntary.
  • Heartbeat is involuntary.
  • The Left part of the brain is generally concerned with language.
  • The Right part of the brain is generally concerned with the appreciation of music.
  • The "Funny Bone" refers to the Ulnar nerve at the elbow.
  • Pectin (pecten oculi) is present in the eyes of Birds.
  • The human body's main organ of balance (equilibrium) is located in the Inner part of the ear.
  • Among the given options, Dolphin has a large brain in proportion to its body size.

Reproductive System

  • Sertoli cells are found in the seminiferous tubules of the testis, providing nourishment to developing sperm.
  • The male reproductive system includes testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands, and penis.
  • The female reproductive system includes ovaries, fallopian tubes (oviducts), uterus, cervix, vagina, and external genitalia.
  • Vas deferens is a component of the male reproductive system, not the female.
  • Adolescence is the period when an individual reaches reproductive maturity.
  • Girls typically begin puberty (adolescence) a year or two earlier than boys.
  • During adolescence, the larynx (voice box) significantly enlarges in boys, leading to a deeper voice; it remains comparatively smaller in girls.
  • The secretion of sebaceous (oil) and sweat glands increases during adolescence, often leading to acne.

Respiratory System

  • Altitude sickness is caused by low partial pressure of oxygen at high altitudes.
  • Frogs breathe through their moist skin (cutaneous respiration).
  • The epithelium of bronchioles is primarily composed of simple cuboidal cells.
  • In birds, sound is produced by the syrinx.

Skeletal System

Microgravity during space flight causes sub1. stantial calcium loss through urine in astronauts. Cartilage is found in the larynx, nose, ear, 2. trachea, bronchioles, and knee joints. Cartilage is NOT found in the urinary blad3. der. The index finger is the finger nearest to the 4. thumb on a human hand. Poisonous fangs of a snake are modified 5. maxillary teeth. Humans have two occipital condyles. 6.

8. Skeletal and Muscle System

Practice MCQs: Human Anatomy and Physiology

Cellular and Tissue Organization

  1. In which one of the following types of connective tissues in animals does fat get stored?

    Asked in: UPSC CDS 1 2018

    1. Adipocyte
    2. Chondrocyte
    3. Osteocyte
    4. Reticulocyte
    Show answer

    Answer: A. Adipocyte

    Adipose tissue is a specialized connective tissue that serves as the body's main energy reserve by storing fat in the form of triglycerides.

  2. Suppose, due to an accident, the delicate lining of the mouth and the oesophagus of a person is injured. In this case, which one of the following tissues will be affected ?

    Asked in: UPSC CDS 1 2022

    1. Smooth muscle
    2. Cuboidal epithelium
    3. Squamous epithelium
    4. Striated muscle
    Show answer

    Answer: C. Squamous epithelium

    Epithelial tissue forms the lining of body cavities, surfaces, and organs. The inner lining (mucosa) of the mouth and oesophagus, which is subject to abrasion from food passage, is lined with stratified squamous epithelium. This type of epithelium is composed of multiple layers of flattened cells, providing a protective barrier. Injury to this lining directly affects this epithelial tissue.

  3. The elemental composition of an adult human body by mass is

    Asked in: UPSC CDS 2 2016

    1. C > O > H > N
    2. O > C > H > N
    3. N > C > H > O
    4. N > C > O > H
    Show answer

    Answer: B. O > C > H > N

    Oxygen is the most abundant element by mass (approx. 65%), largely due to its presence in water (H₂O). Carbon (approx. 18.5%) forms the backbone of organic molecules. Hydrogen (approx. 9.5%) is also abundant in water and organic compounds. Nitrogen (approx. 3.2%) is a key component of proteins and nucleic acids.

  4. Fat in human body is stored in

    Asked in: UPSC CDS 2 2022

    1. Adipose tissue
    2. Red blood cells
    3. Muscle tissue
    4. Epithelial tissue
    Show answer

    Answer: A. Adipose tissue

    - Adipose tissue is a specialized connective tissue composed of adipocytes (fat cells). - These cells store energy in the form of triglycerides (fat). - Adipose tissue also provides insulation, protection for organs, and produces hormones.

  5. Squamous epithelial cells are NOT found in:

    Asked in: UPSC Geoscientist 2020

    1. lining of the mouth.
    2. oesophagus.
    3. skin.
    4. kidney tubules.
    Show answer

    Answer: D. kidney tubules.

    Squamous epithelium consists of flattened, thin cells, often forming smooth, protective, or permeable linings. While stratified squamous epithelium forms protective layers in the mouth, oesophagus, and skin, kidney tubules are primarily lined by cuboidal or columnar epithelium, which are more involved in secretion and absorption. A portion of the loop of Henle in the kidney is lined by thin squamous cells, but the general lining of the tubules is not squamous.

  6. Tissue is formed from cells in which:

    Asked in: UPSC Geoscientist 2021

    1. most cells are similar in structure and function.
    2. all cells perform different functions.
    3. all cells are different in structure.
    4. all cells are different in both structure and function.
    Show answer

    Answer: A. most cells are similar in structure and function.

    Tissues are formed by cells with similar structure and function working together.

  7. The total percentage of carbon present in our human body is

    Asked in: HAS Prelims 2021

    1. 18 to 19 percent
    2. 20 to 25 percent
    3. 15 to 16 percent
    4. None of the above
    Show answer

    Answer: A. 18 to 19 percent

    - The most abundant elements in the human body by mass are Oxygen (~65%), Carbon (~18.5%), four elements constitute about 96% of the body's mass.

  8. In human body percentage of which element is highest ?

    Asked in: MPPSC CS Prelims 2019

    1. Hydrogen
    2. Nitrogen
    3. Carbon
    4. Oxygen
    Show answer

    Answer: D. Oxygen

    Oxygen is the most abundant element by mass in the human body, constituting about 65%. This is primarily because the human body is composed of approximately 60-70% water (H2O), and oxygen makes up a large part of water's molecular weight. Oxygen is also a key component of proteins, carbohydrates, fats, and nucleic acids.

  9. Which animal tissue synthesizes, stores and metabolizes fat ?

    Asked in: MPSC CS Prelims 2014

    1. Epithelial tissue
    2. Adipose tissue
    3. Connective tissue
    4. Muscle tissue
    Show answer

    Answer: B. Adipose tissue

    Adipose tissue is the principal site for fat storage in the body.

Circulatory System and Lymphatic System

  1. The snake bite firstly affects which part of body ?

    Asked in: CGPSC Prelims Exam 2012

    1. nervous system
    2. brain
    3. blood circulation
    4. lungs
    Show answer

    Answer: A. nervous system

    Snake venoms are complex mixtures that are rapidly distributed throughout the body via the blood circulation, and can begin to exert effects directly on blood components or vessel walls immediately upon entering the systemic circulation.

  2. Blood is a type of

    Asked in: UPSC NDA 2 2019

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

    Answer: D. Connective tissue

    - There are four main types of animal tissue: epithelial, connective, muscle, and nervous. - Connective tissue supports and connects other tissues and organs. - Blood consists of cells suspended in plasma, an extracellular matrix. - Blood fits the definition and characteristics of connective tissue.

  3. Which of the following natural substance contains iron (Fe)?

    Asked in: UPPCS Prelims 2020

    1. Chlorophyll
    2. Collagen
    3. Keratin
    4. Myoglobin
    Show answer

    Answer: D. Myoglobin

    - Myoglobin is an iron-containing protein. - Hemoglobin, found in blood, is another well-known iron- containing protein. - Chlorophyll contains magnesium. - Collagen and Keratin are structural proteins that do not contain iron as a central metal atom in their structure.

  4. Oxygen binding protein in body is

    Asked in: WBCS Main Paper 4 2022

    1. Hemoglobin
    2. Myoglobin
    3. Hemery Thrin
    4. All of the above
    Show answer

    Answer: A. Hemoglobin

    - Hemoglobin is the protein in red blood cells responsible for transporting oxygen from the lungs to the body's tissues. - Myoglobin (Option B) is also an oxygen binding protein found in muscle tissue, where it stores oxygen for use during muscle activity. - Hemerythrin (Option C) is an oxygen binding protein found in some marine invertebrates but is not present in humans. - Option D ("All of the above") is incorrect because Hemerythrin is not found in the human body. - While both Hemoglobin and Myoglobin bind oxygen in the human body, Hemoglobin is the main protein for systemic oxygen transport via the bloodstream. Given the options, Hemoglobin is the most prominent oxygen binding protein in the body's circulatory system.

  5. Myoglobin is

    Asked in: WBCS Main Paper 4 2022

    1. Tetramer
    2. Dimer
    3. Monomer
    4. Polymer
    Show answer

    Answer: C. Monomer

    Myoglobin is a relatively small protein consisting of a single polypeptide chain (globin) and one heme group, which binds oxygen.

  6. Jarvic 7 is :

    Asked in: Civil Judge 2018

    1. Pace maker
    2. Artificial limb
    3. Artificial heart
    4. Artificial Cornea
    Show answer

    Answer: C. Artificial heart

    Jarvik-7 is an artificial heart.

Digestive System

  1. Methanol is toxic because

    Asked in: UPSC CDS 1 2024

    1. methanol coagulates the protoplasm
    2. methanol gets oxidised to methanal in liver which coagulates the protoplasm
    3. methanol gets oxidised to acetic acid in liver which coagulates the protoplasm
    4. methanol gets oxidised to CO in liver which coagulates the protoplasm
    Show answer

    Answer: B. methanol gets oxidised to methanal in liver which coagulates the protoplasm

    In the liver, methanol is oxidized by the enzyme alcohol dehydrogenase primarily into formaldehyde, which is also known as methanal. Formaldehyde is a potent toxin that can damage tissues, including causing the denaturation and coagulation of proteins, which is akin to coagulating protoplasm. Formaldehyde is further oxidized to formic acid, which contributes to metabolic acidosis.

  2. The organ of human body which collects carbohydrates in the form of glycogen is

    Asked in: PPSC CS Prelims 2015

    1. Intestine
    2. Stomach
    3. Pancreas
    4. Liver
    Show answer

    Answer: D. Liver

    - After carbohydrates are digested into glucose and absorbed into the bloodstream, the body stores excess glucose for later use. - Glucose is stored primarily as glycogen, a branched polysaccharide, in two main locations: the liver and muscles. - The liver acts as the body's main glucose reservoir, storing a significant amount of glycogen. Liver glycogen is primarily used to maintain stable blood glucose levels between meals through the process of glycogenolysis (breakdown of glycogen into glucose), which releases glucose into the bloodstream. - Muscles also store glycogen, but this muscle glycogen is primarily used as an energy source for the muscle cells themselves during physical activity and is not typically released into the bloodstream to maintain systemic glucose levels.

  3. In vertebrates, smooth endoplasmic reticulum in cells of which organ plays a crucial role in detoxification of toxic compounds ?

    Asked in: UPSC CAPF 2023

    1. Spleen
    2. Intestine
    3. Kidney
    4. Liver
    Show answer

    Answer: D. Liver

    - Smooth endoplasmic reticulum is involved in detoxification. - The liver is the main detoxification organ in vertebrates. - Liver cells (hepatocytes) contain abundant smooth endoplasmic reticulum.

  4. Cholestrol is

    Asked in: UPPCS Prelims 2005

    1. an insecticide
    2. a vitamin
    3. asteroid
    4. an enzyme
    Show answer

    Answer: C. asteroid

    Cholesterol belongs to the class of lipids known as steroids, characterized by a specific four-ring structure.

  5. Which of the following human organs is responsible for detoxication of alcohol?

    Asked in: UPPSC Upper Mains 2010

    1. Liver
    2. Lung
    3. Heart
    4. Kidney
    Show answer

    Answer: A. Liver

    When alcohol is consumed, it is absorbed into the bloodstream and transported throughout the body. The liver contains enzymes, primarily alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), which metabolize alcohol into less toxic substances that can be eliminated from the body.

  6. Which organ of the body is affected most on keeping fast for a long time?

    Asked in: UPPSC Upper Mains 2013

    1. Heart
    2. Intestine
    3. Lung
    4. Kidney
    Show answer

    Answer: D. Kidney

    The kidneys are responsible for filtering metabolic waste products and maintaining homeostasis (stable internal conditions), including fluid and electrolyte balance. Prolonged fasting alters metabolism and generates increased waste products that must be processed by the kidneys.

  7. Diseases of inner parts of the human body are diagnosed through

    Asked in: UPPSC Upper Mains 2014

    1. Cardiograph
    2. Endoscope
    3. Gyroscope
    4. Crestograph
    Show answer

    Answer: B. Endoscope

    An endoscope is an instrument used to examine the internal organs or cavities of the body.

  8. Match List I with List II and select the correct answer using the codes given below the Lists : List I List II (Sub‐ (Physiological role) stance) I. Ptyalin A) Converts angioten-sinogen in blood into angiotensin II. Pepsin B) Digests starch III. Renin C) Digests proteins D) Hydrolyses fats IV. Oxy‐ E) Induces contraction of smooth tocin muscles

    Asked in: UPPCS Prelims 2001

    1. I-B, II-C, III-A, IV-E
    2. I-C, II-D, III-B, IV-E
    3. I-B, II-C, IH-E, IV-A
    4. I-C, II-A, III-B, IV-D
    Show answer

    Answer: A. I-B, II-C, III-A, IV-E

    - Ptyalin (salivary amylase) is an enzyme found in saliva that begins the chemical digestion of starch in the mouth. - Pepsin is a major digestive enzyme in the stomach that breaks down proteins into smaller peptides. - Renin is an enzyme released by the kidneys that initiates the renin-angiotensin system, which regulates blood pressure and fluid balance. - Oxytocin is a hormone that stimulates contractions of smooth muscles, particularly in the uterus during labor and in the mammary glands for milk ejection.

  9. Which of the following is not a gland?

    Asked in: APPSC Draughtman 2008

    1. Stomach
    2. Liver
    3. Kidney
    4. Pancreas
    Show answer

    Answer: C. Kidney

    Glands are primarily involved in secretion. The kidney's main function is filtration and excretion, distinguishing it from the other listed organs which have significant secretory roles.

Homeostasis and Regulatory Mechanisms

  1. Human body contains

    Asked in: BPSC Prelims Exam 64th

    1. about 70% water
    2. 20%-30% water
    3. 10%-20% water
    4. 30%-40% water
    Show answer

    Answer: A. about 70% water

    Water is the most abundant chemical component of the human body, constituting approximately 60-75% of total body weight, depending on age, sex, and body composition. "About 70%" is a commonly cited average figure.

  2. Which one of the following elements is involved in the control of water content of the blood?

    Asked in: UPSC CDS 1 2018

    1. Potassium
    2. Lithium
    3. Rubidium
    4. Caesium
    Show answer

    Answer: A. Potassium

    - Water content of blood is controlled by the balance of electrolytes, primarily sodium in the extracellular fluid. - Potassium is a crucial intracellular electrolyte involved in cell volume and membrane function. - The kidneys, regulated by hormones, control electrolyte and water balance. - Among the options provided, Potassium is the only major electrolyte with a significant role in overall fluid and electrolyte balance impacting blood water content, especially through its influence on kidney function and cellular osmotic balance.

  3. Which programme under the Department of Science and Technology will conduct scientific research on the effects of yoga and meditation on physical and mental health and on cognitive functioning in healthy people as well as in patients with disorders ?

    Asked in: GPSC Prelims CSP 2 2017

    1. SATYAM
    2. VYAYAM
    3. PRANAYAM
    4. None of the above
    Show answer

    Answer: A. SATYAM

    The program supports scientific research that explores the benefits of traditional Indian practices like yoga and meditation using modern scientific tools and methodologies.

  4. What percentage of alcohol in human blood causes death ?

    Asked in: JPSC CS Prelims 2016

    1. 2.0
    2. 3.0
    3. 5.0
    4. 7.0
    Show answer

    Answer: A. 2.0

    Blood Alcohol Content (BAC) is typically measured in grams per 100 milliliters of blood (g/ 100mL), expressed as a percentage or in permille (parts per thousand). While tolerance varies greatly, often considered potentially lethal due to central nervous system depression leading to respiratory extremely high values. Assuming these options 100mL), any level among these would be far beyond the typical lethal threshold and would undoubtedly cause death in most individuals unless they have developed extraordinary tolerance. Given the options, 2.0% (which is 2000 mg/dL or 20 g/L) is the lowest value listed that is undeniably a lethal level of alcohol in the blood.

  5. Which one of the following minerals regulates the acid-base balance of the body ?

    Asked in: MPSC CS Prelims 2015

    1. Ca
    2. Na
    3. K
    4. Fe
    Show answer

    Answer: C. K

    Potassium (K) plays a significant role in regulating intracellular pH and influencing renal mechanisms for acid-base balance.

  6. In vertibrates, inside the cells and tissues, there is a ______ concentration of K⁺ ions and ______ concentration of Na⁺ ions.

    Asked in: MPSC CS Prelims 2020

    1. Low, High
    2. Low, Low
    3. High, Low
    4. High, High
    Show answer

    Answer: C. High, Low

    - Intracellular fluid has high $K^+$ concentration. - Intracellular fluid has low $Na^+$ concentration. - The Na⁺/K⁺ pump is responsible for maintaining these gradients.

  7. Aestivation is seen in

    Asked in: TNPSC CS Prelims 2017

    1. Amphibians
    2. Chimpanzee
    3. Salmon
    4. Squirrels
    Show answer

    Answer: A. Amphibians

    Aestivation is a state of reduced metabolic activity and inactivity that occurs in some animals during periods of heat and dryness (often summer) to conserve energy and water.

  8. Consider the following statements :

    Asked in: TSPSC Group 1 Prelims 2023

    1. Circadian rhythm is endogenous rhythmic change in organism with a periodicity of 24 hours.
    2. Biological clock regulates circadian rhythm.
    3. Sleep and awake phases of humans are due to circadian rhythm.
    4. Heart-beat of humans is an example of circadian rhythm. Which of the above statements are correct ? A. A, B and D only B. A, C and D only C. B, C and D only D. A, B and C only
    Show answer

    Answer: D. Heart-beat of humans is an example of circadian rhythm. Which of the above statements are correct ? A. A, B and D only B. A, C and D only C. B, C and D only D. A, B and C only

    Circadian rhythms are near-24-hour cycles regulating various biological processes. They are governed by internal biological clocks and are distinct from other physiological rhythms like heartbeat, which operate on much shorter timescales.

  9. Which of the following animals can live for the longest duration without drinking water?

    Asked in: UPPCS Prelims 2018

    1. Giraffe
    2. Camel
    3. Kangaroo
    4. Kargaroo rat
    Show answer

    Answer: D. Kargaroo rat

    Kangaroo rats (spelled as Kargaroo rat in the option) are exceptionally well-adapted to arid environments and obtain almost all the water they need from their food (mainly dry seeds) and metabolic processes. They rarely need to drink liquid water, allowing them to survive for long periods without a water source, often longer than camels which, while adapted to conserve water, still need to drink periodically.

Immune System

  1. The most important cell type associated with the immunity of the body is

    Asked in: BPSC Prelims Exam 68th

    1. platelets
    2. lymphocytes
    3. RBCs
    4. More than one of the above
    Show answer

    Answer: B. lymphocytes

    Lymphocytes are the primary cell type responsible for specific, adaptive immunity in the body.

  2. An antibacterial enzyme present in saliva and tears is called

    Asked in: UPSC CDS 1 2024

    1. ribozyme
    2. lipase
    3. lysozyme
    4. isomerase
    Show answer

    Answer: C. lysozyme

    Lysozyme is an enzyme found in saliva and tears that breaks down bacterial cell walls, providing antibacterial protection.

  3. Which one of the following is the special type of milk produced by a lactating mother, essential for the development of immune response of newborn baby in human?

    Asked in: UPSC CDS 2 2018

    1. Breast milk produced after a month of child‐ birth
    2. Transitional milk
    3. Colostrum
    4. Mineralized milk
    Show answer

    Answer: C. Colostrum

    Colostrum is the first milk produced by the mother, typically in the first few days after birth. It is often described as "liquid gold" due to its yellowish color and immense nutritional and immunological value. It is significantly different from mature breast milk. Colostrum is particularly rich in immunoglobulins (antibodies), especially IgA, which provides passive immunity to the newborn, protecting them against various infections. It also contains leukocytes (white blood cells), growth factors, and nutrients highly suited for the newborn's initial needs.

  4. Consider the following terms and their definition/explanation: 1. ... : ... 2. ... : ... 3. ... : Secretion 4. ... : ... Which of the pairs given above are correctly matched?

    Asked in: KPSC KAS Prelims 2014

    1. 2 and 3 only
    2. 1 and 3 only
    3. 1, 2 and 3 only
    4. 1, 2, 3 and 4
    Show answer

    Answer: A. 2 and 3 only

    Answering this question requires knowledge of various terms and their definitions or explanations. The one identifiable item, "Secretion", suggests the question might relate to biology, physiology, or chemistry, requiring understanding of biological or chemical processes.

  5. Match the following : Set – I Set – II

    Asked in: KPSC KAS Prelims 2014

    1. Natural Active 1. Anti-rabies serum Immunity
    2. Natural Passive 2. Acquired after small Immunity pox infection
    3. Artificial Active 3. Transferred from Immunity mother to child
    4. Artificial Passive 4. Develops due to vac‐ Immunity cination Correct match is : A. 2 1 4 3 B. 2 3 4 1 C. 3 4 2 1 D. 4 3 2 1
    Show answer

    Answer: B. Natural Passive 2. Acquired after small Immunity pox infection

    - Natural Active Immunity: Immunity developed after exposure to a pathogen through natural infection (Set II: 2. Acquired after small pox infection). - Natural Passive Immunity: Antibodies are transferred naturally from one person to another, e.g., from mother to child through placenta or breast milk (Set II: 3. Transferred from mother to child). - Artificial Active Immunity: Immunity developed after intentional exposure to an antigen, usually through vaccination (Set II: 4. Develops due to vaccination). - Artificial Passive Immunity: Antibodies are introduced into a person's body from an external source, e.g., through antiserum injection (Set II: 1. Anti-rabies serum).

  6. Which of the following organs is not considered to be immunologically important organ?

    Asked in: KPSC KAS Prelims 2024

    1. Bone marrow
    2. Thymus
    3. Spleen
    4. Pancreas
    Show answer

    Answer: D. Pancreas

    Primary lymphoid organs: Bone marrow and Thymus. Secondary lymphoid organs: Spleen, Lymph nodes, Tonsils, Adenoids, Appendix, Peyer's patches (in the small intestine), and other lymphoid tissues associated with mucosa (MALT).

  7. Which one among the following cells produces antibodies against a foreign antigen ?

    Asked in: UPSC NDA 1 2024

    1. Lymphocytes
    2. Erythrocytes
    3. Eosinophils
    4. Platelets
    Show answer

    Answer: A. Lymphocytes

    Lymphocytes are a type of white blood cell crucial to the immune system. Specifically, B lymphocytes (B cells) are responsible for producing antibodies. Upon encountering an antigen, B cells differentiate into plasma cells, which are highly specialized in synthesizing and secreting large quantities of specific antibodies to target and neutralize the antigen.

  8. Which of the following are the primary lymphoid organs? 1. Bone marrow 2. Thymus 3. Spleen 4. Tonsils Choose the correct answer from the following:

    Asked in: PPSC CS Prelims 2013

    1. 1 and 2
    2. 2 and 3
    3. 1 and 3
    4. 1, 2, 3 and 4
    Show answer

    Answer: A. 1 and 2

    The lymphoid organs are part of the immune system. They are classified into primary and secondary organs. Primary lymphoid organs are where lymphocytes (B cells and T cells) are produced and mature. These are the Bone marrow (site of production of all blood cells, including lymphocytes, and B cell maturation) and the Thymus (site of T cell maturation). Secondary lymphoid organs are where lymphocytes are activated and proliferate in response to antigens. These include the Spleen, lymph nodes, tonsils, adenoids, appendix, and Peyer's patches in the small intestine.

  9. Mother's breast milk provides immunity to new-born babies because it contains :

    Asked in: TSPSC Group 1 Prelims 2022

    1. Immunoglobulin E
    2. Immunoglobulin M
    3. Immunoglobulin A
    4. Immunoglobulin G
    Show answer

    Answer: C. Immunoglobulin A

    Mother's milk, especially colostrum, is rich in antibodies, primarily secretory Immunoglobulin A (IgA). These antibodies are transferred from the mother to the baby and provide passive immunity. Secretory IgA coats the lining of the infant's gastrointestinal and respiratory tracts, preventing pathogens from attaching and entering the body. This is particularly important for protecting the newborn from common infections.

Integumentary System

  1. Human skin is

    Asked in: CGPSC Prelims Exam 2012

    1. A cell
    2. A tissue
    3. An organ
    4. None of these
    Show answer

    Answer: C. An organ

    An organ is a structure composed of different types of tissues that work together to perform specific functions for the body.

  2. Fat present below the skin surface in our body, acts as a barrier against :

    Asked in: HPPSC HPAS Prelims 2013 · UPPCS Prelims 1996

    1. loss of heat from our body
    2. loss of essential body fluids
    3. loss of salts from the body
    4. entry of harmful micro-organisms from the en‐ vironment
    Show answer

    Answer: A. loss of heat from our body

    Subcutaneous fat (adipose tissue) acts as an insulator, reducing heat loss from the body.

  3. हमारी त्वचा के नीचे उपǔस्थत वसा एक अवरोधिक के रूप में ͩकसके ͪवपरीत कायर्त करती है ?

    Asked in: HPPSC HPAS Prelims 2013

    1. हमारे शरीर से ऊष्मा की क्षlत
    2. आविश्यक शारीåरक द्रव्यों की क्षlत
    3. हमारे शरीर से लिविणों की क्षlत
    4. विाताविरण से हाlनकारक सूक्ष्मजीविों का प्रविेश
    Show answer

    Answer: A. हमारे शरीर से ऊष्मा की क्षlत

    The layer of fat located beneath the skin, known as subcutaneous adipose tissue, functions as a thermal insulator. This means it helps to reduce the rate at which heat is lost from the body to the surrounding environment. By trapping heat, it plays a vital role in maintaining a stable internal body temperature, especially in cold conditions.

  4. Fluoride toothpaste is sometimes recommended because fluoride

    Asked in: UPSC NDA 2 2016

    1. prevents plaque formation
    2. hardens the enamel of the tooth
    3. kills pathogenic bacteria
    4. prevents tooth ache
    Show answer

    Answer: B. hardens the enamel of the tooth

    Fluoride works by strengthening the tooth enamel through a process called remineralization. When fluoride is present in the mouth, it is incorporated into the crystalline structure of the enamel, forming fluorapatite. Fluorapatite is more resistant to acid dissolution than hydroxyapatite, the original mineral in enamel. This increased resistance helps protect teeth from decay caused by acids produced by bacteria in plaque, effectively hardening the enamel and making it more resilient to cavities.

  5. Melanin is the natural pigment that gives colour to human skin, hair and the iris. It provides protection against

    Asked in: UPSC NDA 2 2017

    1. Ultraviolet radiation
    2. Infrared radiation
    3. X-ray radiation
    4. Short wave radio radiation
    Show answer

    Answer: A. Ultraviolet radiation

    Melanin is a pigment produced by melanocytes in the skin, hair, and eyes. Its primary function is to absorb harmful ultraviolet (UV) radiation from sunlight, thereby protecting the cells from DNA damage and reducing the risk of skin cancer.

  6. In mammals the mammalian glands are modied gland of following 1. Salivary gland 2. Sebaceous gland 3. Pituitary gland

    Asked in: TNPSC CS Prelims 2019

    1. 1 only
    2. 2 only
    3. 1 and 2 only
    4. 1 and 3 only
    Show answer

    Answer: B. 2 only

    - Mammary glands are exocrine glands that produce milk. - They are classified as modified skin glands. - Standard biological texts identify them as modified apocrine sweat glands. - Sebaceous glands are also exocrine skin glands, producing sebum. - Salivary glands are exocrine glands in the mouth; the Pituitary gland is an endocrine gland in the brain.

  7. Alpha-keratin is a protein present in

    Asked in: UPPCS Prelims 1997

    1. blood
    2. skin
    3. wool
    4. eggs
    Show answer

    Answer: C. wool

    Alpha-keratin is a type of fibrous structural protein that is a primary component of epidermal tissues and appendages in mammals.

  8. Match List I with List II and select the correct answer by using codes given below the lists: List I List II I. Vitamin A) Pepsin II. Enzyme B) Carotene III. Hormone C) Keratin IV. Protein D) Progesterone

    Asked in: UPPCS Prelims 1996

    1. I - A, II - B, III - C, IV - D
    2. I - B, II - A, III - D, IV - C
    3. I - B, II - A, III - C, IV - D
    4. I - A, II - B, III - D, IV – C
    Show answer

    Answer: B. I - B, II - A, III - D, IV - C

    - Vitamins are essential organic compounds that an organism needs in limited amounts. Carotene is a pigment and a precursor to Vitamin A. - Enzymes are biological catalysts, typically proteins. Pepsin is a digestive enzyme. - Hormones are signaling molecules produced by glands. Progesterone is a female sex hormone. - Proteins are complex macromolecules made of amino acids. Keratin is a structural protein found in hair, nails, etc.

  9. The outer layer of Skin is called:

    Asked in: APPSC Draughtman 2008

    1. Ectoderm
    2. Endoderm
    3. Epidermis
    4. Dermis
    Show answer

    Answer: C. Epidermis

    The outermost layer of the skin is called the epidermis.

Muscular System

  1. Accumulation of which one of the following in the muscles of sprinters leads to cramp?

    Asked in: UPSC CDS 1 2018

    1. Lactic acid
    2. Ethanol
    3. Pyruvic acid
    4. Glucose
    Show answer

    Answer: A. Lactic acid

    During intense physical activity like sprinting, muscles may not receive enough oxygen to perform aerobic respiration. In such anaerobic conditions, muscle cells convert glucose into lactic acid through a process called anaerobic glycolysis. The accumulation of lactic acid in muscle tissue lowers the pH and can lead to muscle fatigue, soreness, and cramps.

  2. Cells of which one of the following tissues in animals undergo contraction and relaxation?

    Asked in: UPSC Geoscientist 2020

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

    Answer: A. Muscular tissue

    Muscle cells ( myocytes or muscle fibers) contain specialized proteins, primarily actin and myosin, that interact to cause the cell to shorten (contract) and then return to its original length (relax). This ability is fundamental to movement in animals.

  3. Lactic acid is formed in the muscles during exercise or running. It is formed :

    Asked in: UPSC CAPF 2023

    1. to give extra energy from fat.
    2. to give extra oxygen from lungs.
    3. to give extra energy from glucose.
    4. to give extra energy from vitamins.
    Show answer

    Answer: C. to give extra energy from glucose.

    Lactic acid is produced during anaerobic respiration in muscles, which occurs when oxygen is insufficient for aerobic metabolism. This process allows glycolysis to continue, yielding ATP from glucose for energy.

Nervous System and Sensory Organs

  1. The sensitive area of the human tongue to bitterness is

    Asked in: BPSC Prelims Exam 66th

    1. tip
    2. middle part
    3. posterior part
    4. edge
    Show answer

    Answer: C. posterior part

    - The distribution of taste receptors for different tastes is not strictly localized, but there are areas of higher sensitivity. - Bitterness sensitivity is stronger at the back of the tongue.

  2. A person can see near objects clearly through his eyes but cannot see distant objects clearly. The possible reason(s) for this defect could be : 1. Excessive curvature of the eye lens. 2. The eye-ball has become too small. 3. The focal length of the eye lens is too large. 4. Elongation of the eye-ball. Select the correct answer using the code given below :

    Asked in: UPSC CDS 2 2023

    1. 1 only
    2. 2 and 4 only
    3. 1 and 4 only
    4. 1 and 3 only
    Show answer

    Answer: C. 1 and 4 only

    The condition described, seeing near objects clearly but not distant objects clearly, is known as Myopia or short-sightedness. Myopia occurs when the image of distant objects is focused in front of the retina instead of directly on it. This can be caused by: 1. Excessive curvature of the eye lens: This increases the refractive power of the lens, causing light rays to converge too strongly. 2. Elongation of the eye-ball: If the eyeball is too long from front to back, the retina is located behind the point where the image is focused by a lens of normal power. Options 2 (eye-ball too small) and 3 (focal length of the eye lens is too large - which implies weaker power) would typically lead to Hypermetropia (far- sightedness), where the image is focused behind the retina.

  3. Which of the following statements for persons suffering from presbyopia is/are correct ? 1. They cannot distinguish colours. 2. It usually develops with ageing. 3. They wear either bi-focal lenses consisting of both concave and convex lenses or progressive lenses. Select the answer using the code given below :

    Asked in: UPSC CDS 2 2024

    1. 1 only
    2. 2 only
    3. 1 and 3
    4. 2 and 3
    Show answer

    Answer: D. 2 and 3

    - Presbyopia is a condition that affects the eye's ability to focus, especially on near objects. It is a natural process that occurs with ageing, typically starting around the age of 40. The eye's lens becomes less flexible, making it harder to adjust focus. Thus, statement 2 is correct. - Difficulty distinguishing colours is associated with colour blindness (daltonism), which is a different condition and not typically related to presbyopia. Thus, statement 1 is incorrect. - People with presbyopia often need corrective lenses to see clearly up close. Bifocal lenses have two distinct optical powers (for distance and near vision), while progressive lenses provide a smooth transition between multiple focal lengths. These are common solutions for correcting presbyopia, often combined with other refractive errors like myopia or hyperopia. Thus, statement 3 is correct.

  4. A colour-blind person can not differentiate between the colours ?

    Asked in: CGPSC Prelims Exam 2012

    1. yellow and green
    2. black and blue
    3. red and green
    4. blue and green
    Show answer

    Answer: C. red and green

    Red-green colour blindness is the most prevalent type of colour vision deficiency.

  5. The human eye forms the image of an object at its

    Asked in: CGPSC Prelims Exam 2014 · WBCS Main Paper 4 2021

    1. Cornea
    2. Iris
    3. Pupil
    4. Retina
    Show answer

    Answer: D. Retina

    The human eye functions similarly to a camera. Light enters through the cornea, passes through the pupil (regulated by the iris), and is focused by the lens onto the retina. The retina is the light-sensitive tissue lining the back of the eye; it contains photoreceptor cells (rods and cones) that convert light into electrical signals. These signals are then transmitted to the brain via the optic nerve, where they are interpreted as an image. Therefore, the image of an object is formed on the retina.

  6. The change of focal length of an eye lense is caused by action of the

    Asked in: CGPSC Prelims Exam 2014

    1. Pupil
    2. Retina
    3. Ciliary muscles
    4. Iris
    Show answer

    Answer: C. Ciliary muscles

    The eye's ability to change focus from distant to near objects (and vice versa) is called accommodation. This process is achieved by altering the shape and thus the focal length of the eye lens. The ciliary muscles surrounding the lens contract or relax, which changes the tension on the suspensory ligaments holding the lens, causing the lens to become thicker (for near vision) or thinner (for distant vision).

  7. Which type of image of an object is formed by eye lens on retina?

    Asked in: CGPSC Prelims Exam 2015

    1. Erect and Real
    2. Erect and Virtual
    3. Inverted and Real
    4. Inverted and Virtual
    Show answer

    Answer: C. Inverted and Real

    The eye lens is a convex lens system. A convex lens forms a real and inverted image when the object is placed beyond its focal point. In the case of the human eye, objects we see are typically located at distances greater than the focal length of the eye lens. The retina acts as the screen where the light rays converge. Therefore, the image formed on the retina is real (as it can be projected on a screen) and inverted with respect to the original object.

  8. In eye donation, which one of the following parts of donor's eye is utilized ?

    Asked in: HPPSC HPAS Prelims 2013

    1. Iris
    2. Lens
    3. Cornea
    4. Retina
    Show answer

    Answer: C. Cornea

    Eye donation is primarily a corneal transplant procedure aimed at restoring vision to individuals suffering from corneal blindness caused by disease, injury, or infection. The rest of the eye is typically used for research and training.

  9. In human eyes, the image of an object is formed on

    Asked in: MPPSC CS Prelims 2017

    1. cornea
    2. iris
    3. pupil
    4. retina
    Show answer

    Answer: D. retina

    In the human eye, light enters through the cornea, passes through the pupil (regulated by the iris), is focused by the lens, and forms a sharp image on the retina. The retina is the light-sensitive layer at the back of the eye that contains photoreceptor cells (rods and cones) which convert light into electrical signals. These signals are then transmitted to the brain via the optic nerve, where they are interpreted as vision.

Reproductive System

  1. In which organ sertoli cells are found ?

    Asked in: MPPSC CS Prelims 2021

    1. Ovary
    2. Kidney
    3. Liver
    4. Testis
    Show answer

    Answer: D. Testis

    Sertoli cells, also known as sustentacular cells, are located within the seminiferous tubules of the testis. They play a crucial role in spermatogenesis (the process of sperm production) by providing support and nourishment to the developing sperm cells.

  2. Which of the following is not a part of the female reproductive system in human beings?

    Asked in: WBCS Main Paper 4 2021

    1. Ovary
    2. Uterus
    3. Vas deferens
    4. Fallopian tube
    Show answer

    Answer: C. Vas deferens

    - The question asks for a part NOT belonging to the female reproductive system. - Ovary, Uterus, and Fallopian tube are parts of the female reproductive system. - Vas deferens is a part of the male reproductive system.

  3. Which of the following statements are not correct with reference to physical development of adolescents? (a) In boys, adolescence may begin a year or two earlier than in girls. (b) In adolescence the size of larynx is similar in boys and girls. (c) The secretion of sebaceous gland increases in adolescence. (d) Boys and girls reach reproductive maturity in adolescence. Choose the correct code -

    Asked in: Exam 2024 Group a 2024

    1. (1) (a) & (d)
    2. (2) (a) & (b)
    3. (3) (b) & (c)
    4. (4) (c) & (d)
    Show answer

    Answer: B. (2) (a) & (b)

    Lecturer and Coach (School Edu. Dept.) Comp. The question requires knowledge about the physiological changes that occur during adolescence, specifically in boys and girls.

Respiratory System

  1. 'Altitude sickness' is caused at high altitude due to

    Asked in: UPSC CDS 2 2016

    1. high partial pressure of oxygen
    2. low partial pressure of oxygen
    3. low level of haemoglobin
    4. high partial pressure of carbon dioxide
    Show answer

    Answer: B. low partial pressure of oxygen

    At higher altitudes, the atmospheric pressure is lower. This results in a lower partial pressure of oxygen, which reduces the amount of oxygen that can be taken up by the lungs and delivered to the body's tissues, leading to hypoxia.

  2. Which of the following animals breathes through the skin?

    Asked in: JPSC CS Prelims 2011

    1. Fish
    2. Pigeon
    3. Frog
    4. Cockroach
    Show answer

    Answer: C. Frog

    - Cutaneous respiration (breathing through skin) occurs in some animals. - Frogs are capable of cutaneous respiration using their moist skin.

  3. Epithelium of Bronchioles comprises of :

    Asked in: Food Safety Officer 2022

    1. Simple cuboidal cells
    2. Pseudostratified columnar cells
    3. Simple squamous cells
    4. Pseudostratified sensory cells
    Show answer

    Answer: A. Simple cuboidal cells

    The respiratory epithelium undergoes a change in type as it progresses down the respiratory tract. Larger airways are lined with pseudostratified ciliated columnar epithelium with goblet cells, which transitions to simple cuboidal epithelium in the bronchioles, and finally to simple squamous epithelium in the alveoli.

  4. In birds, sound is produced by ___________. A) Air sacs B) Trachea C) Larynx D) Syrinx

    Asked in: Assistant Accountant 2012

    1. Air sacs
    2. Trachea
    3. Larynx
    4. Syrinx
    Show answer

    Answer: D. Syrinx

    Vocalization in birds occurs through a specialized organ called the syrinx.

Skeletal System

  1. It has been observed that the astronauts lose substantial quantity of calcium through urine during space flight. This is due to _____.

    Asked in: KPSC KAS Prelims 2017

    1. Hypergravity
    2. Microgravity
    3. Intake of dehydrated food tablets
    4. Low temperature in cosmos
    Show answer

    Answer: B. Microgravity

    In the absence of gravity, the mechanical stress on bones is significantly reduced. Bones require mechanical load to maintain their density and strength. Without this load, bone resorption increases and bone formation decreases, leading to bone demineralization and increased calcium release into the blood, which is then filtered by the kidneys and excreted in urine.

  2. Cartilage is NOT found in

    Asked in: UPSC NDA 2 2020

    1. larynx
    2. nose
    3. ear
    4. urinary bladder
    Show answer

    Answer: D. urinary bladder

    Cartilage is a structural component of the skeletal system and certain organs, providing support and flexibility. It is different from muscle tissue, which forms the walls of organs like the urinary bladder.

  3. In which part or organ of human body cartilage is NOT found ?

    Asked in: UPSC NDA 2 2024

    1. Nose
    2. Trachea
    3. Bronchiole
    4. Knee joint
    Show answer

    Answer: C. Bronchiole

    The respiratory tract contains cartilage in the trachea and bronchi to maintain their structure and prevent collapse. As the airways branch into smaller bronchioles (less than 1 mm in diameter), the cartilage rings disappear, and the walls become primarily smooth muscle and elastic tissue, which allows for regulation of airflow through bronchoconstriction and bronchodilation.

  4. On a human hand, the finger nearest to thumb is the

    Asked in: ASSISTANT ENGINEER(ELECTRICAL) 2016

    1. ring finger
    2. index finger
    3. middle finger
    4. pinky
    Show answer

    Answer: B. index finger

    Basic anatomical knowledge of the human hand is being tested.

  5. Poisonous fangs of a snake are modified form of :

    Asked in: RO ARO pre 2016

    1. Mandibular teeth
    2. Palatine teeth
    3. Canine teeth
    4. Maxillary teeth
    Show answer

    Answer: D. Maxillary teeth

    Snakes' fangs are a crucial part of their venom delivery system. They are not just any teeth but specifically adapted structures for injecting venom. Maxillary teeth are found in the upper jaw and are the primary location for these specialized fangs in venomous snakes.

  6. The number of occipital condyles in man is-

    Asked in: POST GRADUATE TEACHER (PGT) 2018

    1. One
    2. Two
    3. Three
    4. Four
    Show answer

    Answer: B. Two

    The number of occipital condyles can vary among different vertebrate species. Monocondylic skulls