TS Inter 2nd Year – Zoology Previous Paper 2022

PAPER – II

(English Version)
Time: 3 hours
Max. Marks: 60

SECTION – A

10 × 2 = 20

Answer ANY TEN Questions

Each Question carries TWO marks

All are very short answer type questions.

1. What are conchae?

Answer: Conchae are bony structures found in the nasal cavity that project inward from the lateral walls. They are covered with mucous membranes and help to increase the surface area of the nasal cavity, which warms, humidifies, and filters the air we breathe.

2. Name the muscles that help in normal breathing movements.

  • Diaphragm: This is the primary muscle of respiration. It contracts and flattens during inhalation, increasing the volume of the chest cavity.
  • Intercostal muscles: Located between the ribs, these muscles help expand and contract the chest cavity during breathing.

3. Sino-atrial node is called the pacemaker of our heart. Why?

  • The Sino-atrial (SA) node is a small group of specialized cardiac muscle cells situated in the right atrium of the heart.
  • It has the unique ability to spontaneously generate electrical impulses at a regular rate.
  • These impulses spread throughout the heart, initiating the sequence of contractions that drive the heartbeat.
  • Due to this inherent rhythm-setting ability, the SA node is rightly called the pacemaker of the heart.

4. What are the columns of Bertin?

  • The columns of Bertin are inward projections of the renal cortex (the outer layer of the kidney) that extend between the renal pyramids (the triangular-shaped structures in the inner region of the kidney).
  • They contain blood vessels and nephrons (the functional units of the kidney) that play a role in urine formation.

5. Define glomerular filtration.

  • Glomerular filtration is the initial and crucial step in the process of urine formation.
  • It occurs within the glomerulus, a network of capillaries located within the nephron (the functional unit of the kidney).
  • Blood pressure forces water and small molecules (such as glucose, amino acids, and ions) to filter out of the blood in the glomerulus into the Bowman’s capsule, which surrounds the glomerulus.
  • Large molecules like proteins and blood cells are retained in the blood.

6. What is triad system?

  • The triad system is a structural arrangement found in skeletal muscle fibers.
  • It comprises a T-tubule (transverse tubule) and two adjacent terminal cisternae of the sarcoplasmic reticulum.
  • T-tubules are invaginations of the sarcolemma (the muscle cell membrane) that penetrate deep into the muscle fiber.
  • Terminal cisternae are specialized regions of the sarcoplasmic reticulum (a network of interconnected tubules that store calcium ions).
  • The triad system plays a critical role in the excitation-contraction coupling process, enabling the rapid and synchronized contraction of muscle fibers.

7. Name the cranial meninges covering the brain of man.

  • The brain is protected by three layers of membranes called meninges:
    • Dura mater: The outermost, tough, and fibrous layer.
    • Arachnoid mater: A delicate, web-like middle layer.
    • Pia mater: The innermost, thin, and vascular layer that closely adheres to the surface of the brain.

8. Which hormone is called anti-diuretic hormone? Write the name of the gland that secretes it.

  • The hormone called anti-diuretic hormone (ADH) is also known as vasopressin.
  • It is produced by the hypothalamus and subsequently released by the posterior pituitary gland.
  • ADH regulates water balance in the body by increasing the reabsorption of water from the collecting ducts in the kidneys, thereby reducing urine output.

9. “Colostrum is very much essential for the new born infants”. Justify.

  • Colostrum is the initial milk produced by the mammary glands after childbirth.
  • It is highly beneficial for newborns due to its rich content of:
    • Antibodies: Particularly immunoglobulin A (IgA), which provides passive immunity to the newborn against infections.
    • Growth factors: These support the development and maturation of the newborn’s immune system and digestive system.
    • Other nutrients: Essential for the overall health and well-being of the newborn.

10. Which hormone is commonly known as fight and flight hormone?

  • Epinephrine (adrenaline) and norepinephrine (noradrenaline) are often referred to as the “fight-or-flight” hormones.
  • They are released by the adrenal medulla in response to stressful or threatening situations.
  • These hormones trigger the body’s physiological response to stress, including increased heart rate, blood pressure, blood sugar levels, and alertness, preparing the body for a quick response to danger.

11. What is haplo-diploidy?

Haplo-diploidy is a sex determination system found in some insects, including bees, wasps, and ants. In this system:

  • Males develop from unfertilized eggs and are haploid, meaning they have only one set of chromosomes.
  • Females develop from fertilized eggs and are diploid, meaning they have two sets of chromosomes.

This system results in unusual relatedness patterns within colonies, as sisters share a higher proportion of their genes compared to their offspring.

12. List out any two applications of DNA fingerprinting technology.

DNA fingerprinting technology has a wide range of applications, including:

  1. Paternity testing: By comparing the DNA profiles of a child, the mother, and a potential father, DNA fingerprinting can establish paternity with high accuracy.

  2. Forensic investigations: DNA evidence collected from crime scenes can be compared to DNA profiles from suspects to identify potential perpetrators.

13. What is pleiotropy?

Pleiotropy is a phenomenon where a single gene influences multiple phenotypic traits. In other words, a mutation in a single gene can have a variety of effects on an organism’s appearance, physiology, or behavior.

14. Define the terms layer and broiler.

In poultry farming, the terms “layer” and “broiler” refer to different types of chickens raised for specific purposes:

  • Layer: A layer is a hen that is bred and raised specifically for egg production. They are typically smaller and more active than broilers.

  • Broiler: A broiler is a chicken bred and raised for meat production. They are typically larger and have a faster growth rate than layers.

15. Mention any four fish by-products.

Fish by-products are the non-edible parts of fish that are often processed and used for various purposes. Some common fish by-products include:

  1. Fish meal: Made from ground-up fish parts, it is used as a high-protein feed for livestock and aquaculture.

  2. Fish oil: Extracted from fish tissue, it is rich in omega-3 fatty acids and is used as a dietary supplement and in various industrial applications.

  3. Fish glue: Obtained from fish bones and skin, it is used in various industrial applications, such as woodworking and paper manufacturing.

  4. Fish gelatin: Extracted from fish bones and skin, it is used in food and pharmaceutical industries.

SECTION – B

  • Answer ANY SIX questions.
  • Each question carries FOUR marks.

16. Explain the process of inspiration and expiration under normal conditions.

Inspiration (Inhalation):

  1. Diaphragm Contraction: The diaphragm, a dome-shaped muscle below the lungs, contracts and flattens downwards. This increases the vertical dimension of the chest cavity.
  2. Intercostal Muscle Contraction: The external intercostal muscles between the ribs contract, pulling the ribs upward and outward. This increases the lateral and anterior-posterior dimensions of the chest cavity.
  3. Increased Volume, Decreased Pressure: The combined actions of the diaphragm and intercostal muscles lead to an increase in the volume of the thoracic cavity. According to Boyle’s Law, this increase in volume results in a decrease in air pressure within the lungs.
  4. Air Inflow: As the pressure within the lungs becomes lower than the atmospheric pressure, air rushes into the lungs through the respiratory tract.

Expiration (Exhalation):

  1. Diaphragm Relaxation: The diaphragm relaxes and returns to its dome-shaped position, decreasing the vertical dimension of the chest cavity.
  2. Intercostal Muscle Relaxation: The external intercostal muscles relax, allowing the ribs to move downward and inward. This decreases the lateral and anterior-posterior dimensions of the chest cavity.
  3. Decreased Volume, Increased Pressure: The combined actions of the diaphragm and intercostal muscles lead to a decrease in the volume of the thoracic cavity. According to Boyle’s Law, this decrease in volume results in an increase in air pressure within the lungs.
  4. Air Outflow: As the pressure within the lungs becomes higher than the atmospheric pressure, air is forced out of the lungs through the respiratory tract.

17. Describe disorders of the respiratory system.

The respiratory system can be affected by various disorders, including:

  • Asthma: A chronic condition characterized by airway inflammation and constriction, leading to difficulty breathing, wheezing, and coughing.
  • Chronic Obstructive Pulmonary Disease (COPD): A group of lung diseases, including chronic bronchitis and emphysema, that cause airflow obstruction and difficulty breathing.
  • Pneumonia: An infection that inflames the air sacs in the lungs, often causing coughing, fever, and difficulty breathing.
  • Tuberculosis: A bacterial infection that primarily affects the lungs, causing coughing, fever, weight loss, and night sweats.
  • Lung Cancer: Uncontrolled growth of abnormal cells in the lungs, often caused by smoking.
  • Acute Respiratory Distress Syndrome (ARDS): A life-threatening condition characterized by fluid accumulation in the lungs, leading to severe breathing difficulties.

18. Differentiate vertebrates on the basis of the nitrogenous waste products they excrete, giving examples.

Vertebrates can be classified based on the primary nitrogenous waste product they excrete:

  • Ammonotelic Animals: Excrete ammonia as the primary nitrogenous waste. Ammonia is highly toxic and requires large amounts of water for dilution. Examples include bony fishes and aquatic invertebrates.
  • Ureotelic Animals: Excrete urea as the primary nitrogenous waste. Urea is less toxic than ammonia and requires less water for excretion. Examples include mammals, amphibians, and some marine fishes.
  • Uricotelic Animals: Excrete uric acid as the primary nitrogenous waste. Uric acid is relatively non-toxic and requires minimal water for excretion. Examples include birds, reptiles, and insects.

19. Describe the internal structure of the kidney of man.

The human kidney is a bean-shaped organ with an intricate internal structure. Here’s a brief description:

  • Cortex: The outer layer of the kidney, containing numerous nephrons (the functional units of the kidney).
  • Medulla: The inner layer of the kidney, composed of renal pyramids, which contain collecting ducts that carry urine.
  • Pelvis: A funnel-shaped structure that collects urine from the collecting ducts and directs it to the ureter.
  • Nephrons: Each nephron consists of a glomerulus (a network of capillaries), Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct. These structures are responsible for filtering blood, reabsorbing essential substances, and secreting waste products to form urine.

20. Draw a labelled diagram of the T.S. of the spinal cord of man.

(A labeled diagram of the transverse section of the spinal cord should be drawn here. It should include the following structures: grey matter, white matter, dorsal horn, ventral horn, central canal, dorsal root, ventral root, and spinal nerve.)

21. Describe the important steps in muscle contraction.

Muscle contraction is a complex process involving the interaction of actin and myosin filaments within muscle fibers. The key steps include:

  1. Nerve Impulse: A nerve impulse triggers the release of acetylcholine at the neuromuscular junction.
  2. Calcium Release: Acetylcholine binds to receptors on the muscle fiber membrane, leading to the release of calcium ions from the sarcoplasmic reticulum.
  3. Cross-Bridge Formation: Calcium ions bind to troponin, causing a conformational change that exposes the myosin-binding sites on actin filaments. Myosin heads then bind to actin, forming cross-bridges.  

     

  4. Power Stroke: The myosin heads pivot, pulling the actin filaments towards the center of the sarcomere, shortening the muscle fiber.
  5. Cross-Bridge Detachment: ATP binds to the myosin head, causing it to detach from the actin filament.
  6. Myosin Re-energizing: ATP is hydrolyzed by the myosin head, providing the energy for the myosin head to return to its original position.
  7. Cycle Repetition: The cycle of cross-bridge formation, power stroke, detachment, and re-energizing continues as long as calcium ions are present and ATP is available.

22. Give an account of the secretions of the pituitary gland.

The pituitary gland, often called the “master gland,” secretes a variety of hormones that regulate various bodily functions. Some of the major secretions include:

    • Anterior Pituitary:
        • Growth hormone (GH)
        • Prolactin
        • Thyroid-stimulating hormone (TSH)
        • Adrenocorticotropic hormone (ACTH)
        • Follicle-stimulating hormone (FSH)
        • Luteinizing hormone (LH)  

  • Posterior Pituitary:
      • Antidiuretic hormone (ADH)
    • Oxytocin  

23. Write short notes on B-cells.

B-cells are a type of lymphocyte (white blood cell) that play a crucial role in the humoral immune response. They function by producing antibodies, which are proteins that bind to specific antigens (foreign substances) and neutralize them.

24. Write a note on Addison’s disease and Cushing’s syndrome.

  • Addison’s Disease: This condition is caused by the insufficient production of cortisol and aldosterone by the adrenal glands. Symptoms include fatigue, weakness, weight loss, low blood pressure, and skin pigmentation.  

  • Cushing’s Syndrome: This condition results from excessive exposure to cortisol, often due to an adrenal tumor or the use of glucocorticoid medications. Symptoms include weight gain, muscle weakness, high blood pressure, mood changes, and skin thinning.

25. Describe the surgical methods of contraception.

Surgical methods of contraception are permanent and involve procedures that prevent the release of eggs or sperm. They include:

  • Tubal Ligation: In women, the fallopian tubes are blocked or cut to prevent the egg from reaching the uterus.
  • Vasectomy: In men, the vas deferens are cut or blocked to prevent sperm from being released.

26. How is sex determined in human beings?

In humans, sex is determined by the presence of sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The presence of the Y chromosome triggers the development of male characteristics.  

27. Is sex education necessary in schools? Why?

Yes, sex education is crucial in schools. It provides young people with accurate and age-appropriate information about sexuality, relationships, and reproductive health. This knowledge empowers them to make informed decisions about their bodies and relationships, reduces risky sexual behaviors, and promotes healthy sexual development.

28. Honey bees are economically important-justify.

Honey bees play a vital role in agriculture and the environment. They are essential pollinators for a wide range of crops, contributing significantly to food production. Additionally, honey, beeswax, and other bee products have commercial value and are used in various industries.

29. Discuss in brief about ‘Avian Flu’.

Avian flu, also known as bird flu, is a highly contagious viral infection that primarily affects birds. Some strains of avian flu can also infect humans, although human-to-human transmission is rare. Avian flu outbreaks can have significant economic impacts on the poultry industry and pose a potential threat to public health.

SECTION – C

Answer any TWO questions.

Each question carries EIGHT marks.

All are long answer type questions.

Draw labelled diagrams wherever necessary.

30. What are multiple alleles? Describe multiple alleles with the help of ABO blood groups in man.

Multiple Alleles:

  • Multiple alleles refer to the presence of more than two alternative forms (alleles) of a single gene at the same locus on a chromosome.
  • While most genes have only two alleles, some genes exhibit multiple alleles within a population.

ABO Blood Groups in Humans:

  • The ABO blood group system is a classic example of multiple alleles.

  • The gene responsible for the ABO blood group is located on chromosome 9.

  • There are three major alleles for this gene:

    • IA: Codes for the production of A antigen on red blood cells.
    • IB: Codes for the production of B antigen on red blood cells.
    • i: Codes for the production of neither A nor B antigen.

  • Possible Genotypes and Phenotypes:

    • IAIA or IAi: Blood group A
    • IBIB or IBi: Blood group B
    • IAIB: Blood group AB (both A and B antigens are present)
    • ii: Blood group O (no antigens present)

  • Importance: Understanding multiple alleles in the ABO blood group system is crucial for blood transfusions. Blood transfusions must be compatible to avoid potentially life-threatening reactions.

31. Describe the structure of the heart of man with the help of a neat labelled diagram.

(A labeled diagram of the human heart should be drawn here. It should include the following structures:

  • Four Chambers: Right atrium, right ventricle, left atrium, left ventricle
  • Valves: Tricuspid valve, pulmonary valve, mitral valve (bicuspid valve), aortic valve
  • Major Blood Vessels: Superior vena cava, inferior vena cava, pulmonary artery, pulmonary veins, aorta)

Description:

    • The human heart is a muscular organ located in the chest cavity.
    • It is divided into four chambers: two upper chambers called atria and two lower chambers called ventricles.
    • The right side of the heart pumps deoxygenated blood to the lungs for oxygenation.
  • The left side of the heart pumps oxygenated blood to the rest of the body.  
  • Valves between the chambers ensure unidirectional blood flow.

32. Describe the male reproductive system of a man. Draw a labelled diagram of it.

(A labeled diagram of the male reproductive system should be drawn here. It should include the following structures:

  • Testes: Produce sperm and testosterone.
  • Scrotum: A pouch that holds and protects the testes.
  • Epididymis: Stores and matures sperm.
  • Vas deferens: Transports sperm from the epididymis to the ejaculatory ducts.
  • Seminal Vesicles: Produce a fluid that nourishes and protects sperm.
  • Prostate Gland: Produces a fluid that contributes to semen.
  • Urethra: A tube that carries both urine and semen.
  • Penis: The male organ of sexual intercourse and urination.

Description:

  • The male reproductive system is responsible for producing sperm and delivering them to the female reproductive tract.
  • The testes are the primary male reproductive organs, producing sperm and testosterone.
  • Testosterone is responsible for the development of male secondary sexual characteristics.
  • During ejaculation, sperm is released from the testes, travels through the reproductive tract, and is mixed with fluids from the seminal vesicles and prostate gland to form semen.

33. Give a brief account of the structure and functions of the brain of man.

Structure:

  • The brain is a complex organ composed of billions of neurons and glial cells.
  • It is divided into three major parts:
    • Cerebrum: The largest part of the brain, responsible for higher functions such as thought, perception, and voluntary movement. It is further divided into two hemispheres (right and left) connected by the corpus callosum.
    • Cerebellum: Located below the cerebrum, it is responsible for coordination, balance, and motor learning.
    • Brainstem: Connects the brain to the spinal cord and controls vital functions such as breathing, heart rate, and blood pressure. It consists of the midbrain, pons, and medulla oblongata.  

Functions:

  • Sensory Integration: Receives and processes sensory information from the body.
  • Motor Control: Initiates and coordinates voluntary movements.
  • Cognition: Responsible for thought, memory, learning, and language.
  • Emotions: Regulates emotions such as fear, anger, and happiness.
  • Homeostasis: Maintains internal bodily functions such as temperature, blood pressure, and hormone levels.

Note: These are brief answers. More detailed explanations and diagrams may be required depending on the level of the examination.