RBSE Solutions Class 12 Biology Chapter 42 Bio-Medical Technologies

Rajasthan Board RBSE Class 12 Biology Chapter 42 Bio-Medical Technologies

RBSE Class 12 Biology Chapter 42 Multiple Choice Questions

 

Question 1. Which of the following is used to measure blood haemoglobin?
(a) Haemocytometer
(b) Haemoglobinometer
(c) Westergren method
(d) Wintrobe method
Answer: (b) Haemoglobinometer
In simple words: A haemoglobinometer is a special tool designed to accurately measure the amount of haemoglobin in a blood sample. This measurement is important for checking a person's blood health.

🎯 Exam Tip: Always remember the specific instruments used for common medical tests, as they are key terms in biology.

 

Question 3. Which is used to diagnose the heart-related diseases?
(a) EEG
(b) ECG
(c) RIA
(d) CAT scan
Answer: (b) ECG
In simple words: An ECG, or Electrocardiogram, is a test that records the electrical signals from your heart. Doctors use it to check for different heart problems because it shows how well your heart is beating.

🎯 Exam Tip: Distinguish between similar-sounding diagnostic tools like EEG (for the brain) and ECG (for the heart) to avoid common errors.

 

Question 4. Which of the following radiations are used in a CT Scan?
(a) α - rays
(b) β - rays
(c) γ - rays
(d) X – rays
Answer: (d) X – rays
In simple words: A CT scan, which stands for Computed Tomography, uses a series of X-ray images taken from different angles. These images are then put together by a computer to create detailed cross-sectional pictures of your bones, blood vessels, and soft tissues inside your body.

🎯 Exam Tip: Remember that CT scans rely on X-rays to generate their images, making them effective for visualizing bone structures and internal organs.

 

Question 5. Full name of MRI is:
(a) Multiple Resonance Imaging
(b) Magnetic Radio Imaging
(c) Magnetic Resonance Indicator
(d) Multiple Radio Imaging
Answer: (c) Magnetic Resonance Indicator
In simple words: MRI, as given in this option, stands for Magnetic Resonance Indicator. It is a medical imaging technique that uses strong magnetic fields and radio waves to create detailed images of organs and soft tissues within the body.

🎯 Exam Tip: Be sure to memorize the full forms of common medical abbreviations accurately, as they are often tested directly.

RBSE Class 12 Biology Chapter 42 Very Short Answer Questions

 

Question 1. What is used for Total leucocyte count?
Answer: When the number of White Blood Cells (WBC) becomes more than normal, it shows a condition called leucocytosis. This condition often signals an infection or inflammation in the body. An instrument called a haemocytometer is typically used to count leucocytes.
In simple words: A high number of WBCs, or leucocytes, can mean there is an infection or problem in the body.

🎯 Exam Tip: While the given answer focuses on the implication, remember that a haemocytometer is the instrument specifically used for performing a total leucocyte count.

 

Question 3. In which diseases, the value of ESR increases.
Answer: The Erythrocyte Sedimentation Rate (ESR) increases in several diseases. These include Rheumatoid Arthritis, Multiple Myeloma, and Tuberculosis (TB). An elevated ESR often indicates inflammation or other changes in the body. This is a non-specific test, meaning it can show inflammation but not the exact cause.
In simple words: The ESR test shows higher numbers in diseases like rheumatoid arthritis, multiple myeloma, and tuberculosis.

🎯 Exam Tip: List a few specific diseases where ESR elevation is a known indicator, showing your understanding of its clinical relevance.

 

Question 4. Name the instrument that records heartbeats.
Answer: The instrument that records heartbeats is called a Stethoscope. Doctors use it to listen to sounds inside the body, especially the heart and lungs. It helps them check for any unusual sounds.
In simple words: A stethoscope is used by doctors to listen to and record heartbeats.

🎯 Exam Tip: Knowing the names and basic functions of common medical instruments like the stethoscope is important.

 

Question 5. EEG is related to the diagnosis of which organ functioning?
Answer: EEG stands for Electroencephalogram, and it is related to the diagnosis of Brain functioning. An EEG records the electrical activity of the brain using small sensors attached to the scalp. It helps doctors find problems with brain activity.
In simple words: EEG is used to check how the brain is working.

🎯 Exam Tip: Clearly link each diagnostic technique (like EEG) to the specific organ or system it evaluates (like the brain).

 

Question 6. Which is used in place of X – rays in MRI.
Answer: In MRI (Magnetic Resonance Imaging), strong magnetic fields and radio waves are used instead of X-rays. This imaging technique works by detecting the electric charge and low magnetic field of the hydrogen atoms' nuclei. Hydrogen atoms are abundant in the water molecules and proteins found throughout the body, making them ideal for creating detailed images of soft tissues. This is why MRI is considered safe as it avoids radiation exposure.
In simple words: MRI uses strong magnets and radio waves instead of X-rays to create detailed images of the body.

🎯 Exam Tip: Highlight that MRI avoids harmful ionizing radiation by using magnetic fields and radio waves, making it different from X-ray based imaging like CT scans.

 

Question 7. Which crystals are used in sonography?
Answer: Lead Zirconate Crystals are used in sonography. These special crystals have piezoelectric properties, meaning they can convert electrical energy into sound waves and vice-versa. This allows the sonography machine to send out high-frequency sound waves and then listen for their echoes to create images of internal body structures.
In simple words: Sonography uses Lead Zirconate Crystals to make sound waves and create pictures inside the body.

🎯 Exam Tip: Mentioning the specific crystal (Lead Zirconate) and its property (piezoelectric) demonstrates a deeper understanding of sonography technology.

RBSE Class 12 Biology Chapter 42 Short Answer Questions

 

Question 1. Explain in short about the Westergren method of ESR.
Answer: The Erythrocyte Sedimentation Rate (ESR) measures how quickly red blood cells settle down in a blood sample. Blood cells are heavier than plasma, so they slowly sink to the bottom when left undisturbed. The speed at which they settle is called the ESR. Two main methods measure ESR: the Westergren method and the Wintrobe method. The Westergren method is more commonly used in labs for ESR testing. In this method, a Westergren tube is filled with blood mixed with an anticoagulant (like Trisodium citrate) up to the zero mark. The tube is then placed vertically in a special stand. After exactly one hour, the upper level of the settled red blood cells is read on the tube. This reading gives the ESR value. For a healthy person, the normal ESR value is typically 0-16 mm per hour for males and 0-20 mm per hour for females. An increased ESR can indicate inflammation or disease.
In simple words: The Westergren method measures how fast red blood cells settle in a blood tube over an hour, which helps detect inflammation or disease.

🎯 Exam Tip: Clearly state the principle of sedimentation, the specific anticoagulant used, the Westergren tube, and the observation period (one hour) for a complete explanation.

 

Question 2. Write the medical significance of Differential Leucocyte Counts.
Answer: Differential Leucocyte Counts (DLC) are medically important because any unusual changes in the numbers of different types of white blood cells (leucocytes) can point to specific diseases. By looking at these changes, doctors can get closer to a correct diagnosis, which then helps them choose the right treatment. For example, if there's an increase or decrease in a certain type of white blood cell, it can signal an infection, allergy, or other medical condition. The table below describes some of these conditions:

In simple words: DLC helps doctors find diseases because changes in white blood cell types can show if there's an infection, allergy, or other health problems.

🎯 Exam Tip: Focus on linking specific changes in each type of white blood cell (neutrophils, eosinophils, lymphocytes, etc.) to the common diseases they indicate, as this demonstrates detailed knowledge.

Use of ECG:

An Electrocardiogram (ECG) is a vital diagnostic tool with several uses in medicine.

• It is used to detect various cardiac disorders such as arrhythmias (irregular heartbeats), conduction disturbances (problems with electrical signals), and myocardial ischemia (reduced blood flow to the heart).
• ECG can also reveal other significant findings related to life-threatening metabolic disturbances, like hyperkalemia (high potassium levels), or an increased susceptibility to sudden cardiac death, as seen in conditions like QT prolongation syndrome.
• Furthermore, ECG helps in studying the heart's rate and rhythm and in diagnosing specific cardiac conditions like myocardial infarction (MI), also known as a heart attack, and various coronary artery diseases.

In simple words: ECG is used to find heart problems like irregular beats, poor blood flow, and to study heart rate and health.

🎯 Exam Tip: When discussing ECG uses, categorize them into rhythm problems, blood flow issues, and metabolic disturbances for a comprehensive answer.

 

Question 4. Write the significance of Sonography technique.
Answer: The sonography technique is very important in medicine. It is commonly used to check the growth of a baby during pregnancy and to find any problems or abnormalities in an adult's body. Sonography can also provide a clear picture of blood flowing through the beating heart, which helps doctors assess heart function. This non-invasive method uses sound waves to create images, avoiding radiation exposure.
In simple words: Sonography is important for checking baby's growth, finding body problems, and seeing blood flow in the heart.

🎯 Exam Tip: Emphasize both its widespread use in prenatal care and its diagnostic value for various conditions in adults, highlighting its non-invasive nature.

 

Question 5. Explain the role of ESR in disease diagnosis.
Answer: The Erythrocyte Sedimentation Rate (ESR) plays a significant role in disease diagnosis, especially as an indicator of inflammation. The value of ESR often increases in many chronic diseases, such as Tuberculosis (TB), Arthritis, and Allergies. It also typically rises during pregnancy, in cases of Anaemia, and with old age. An increased ESR doesn't point to a specific disease but signals that there is an inflammatory process happening somewhere in the body.
In simple words: ESR helps diagnose diseases by showing if there is inflammation in the body, as its value goes up in many illnesses, pregnancy, and old age.

🎯 Exam Tip: Note that ESR is a non-specific marker of inflammation, meaning it indicates the presence of an issue but not its exact cause, and list examples of conditions that can elevate it.

 

Question 6. Why MRI technique is better and safe than a CT scan.
Answer: The MRI technique is often considered better and safer than a CT scan for several reasons. MRI provides images with very high contrast from all angles of the body, allowing for a clearer view of soft tissues. This technique is especially good at distinguishing between the white and grey matter of the brain, which is crucial for neurological diagnoses. Additionally, MRI does not use ionizing radiation, unlike CT scans, making it a safer option, particularly for repeated scans or for sensitive patients like pregnant women and children. Its ability to show subtle differences in tissue types makes it superior for certain conditions.
In simple words: MRI is better than CT scans because it shows clear pictures of soft tissues and brain parts without using harmful radiation, making it safer.

🎯 Exam Tip: Focus on MRI's superior soft tissue contrast and lack of ionizing radiation as key advantages over CT scans when comparing the two techniques.

RBSE Class 12 Biology Chapter 42 Essay Type Questions

 

Question 1. Explain in detail about the process of haemoglobin measurement in blood.
Answer: The measurement of haemoglobin in blood is crucial because a low level often indicates Anaemia. The normal range for haemoglobin varies with age and gender, as shown in the table below:

Haemoglobin content is commonly measured using a Haemoglobinometer, with Sahli's Haemoglobinometer being a traditional choice. Other tools like the Photohaemoglobinometer and Autoanalyzer are also used.
Sahli's Haemoglobinometer: This device consists of a graduated tube placed between two standard matching tubes in a stand. The graduated tube is filled with N/10 HCl solution up to the zero point. Using a haemoglobin pipette, 0.02 ml of blood is added to the measuring tube and thoroughly mixed with the N/10 HCl. The N/10 HCl then converts the haemoglobin into a brown substance called haematin. Distilled water is added drop by drop to the measuring tube, with continuous mixing, until the color of the haematin solution perfectly matches the color of the standard tubes. Once the colors match, the haemoglobin content is read directly from the graduated scale on the measuring tube. This method provides a visual estimation of haemoglobin levels.
In simple words: Haemoglobin is measured using a Haemoglobinometer, often the Sahli's method, where blood is mixed with acid, diluted until its color matches a standard, and then read from a tube to find the haemoglobin level.

🎯 Exam Tip: Detail the steps of the Sahli's method, including the reagents used (N/10 HCl, distilled water) and the principle of color matching, along with citing normal haemoglobin ranges.

 

Question 2. Explain the process and components of an Electrocardiogram (ECG) in detail.
Answer: An Electrocardiogram (ECG) is a recording of the heart's electrical activity. It is recorded on special graph paper that is divided into 1 mm² grid-like boxes. A normal ECG tracing typically shows several distinct components: the P wave, QRS complex, and the ST-T-U complex.

• The P wave is a small upward deflection that represents atrial depolarization, which is when the atria contract.
• The QRS Complex represents the rapid ventricular depolarization (systole), which is when the ventricles contract. It includes a small downward deflection (Q wave), a rapid upright stroke (R wave), and a small downward deflection (S wave).
• The ST-T-U complex includes the ST segment, T wave, and U wave. This part represents ventricular repolarization (diastole), which is when the ventricles relax and recharge.
• The J point marks the junction between the end of the QRS complex and the beginning of the ST-segment.
• Atrial repolarization is usually too low in amplitude to be detected on a standard ECG.
• There are four major ECG Intervals that help assess heart function:

1. R-R interval: This is used to calculate the heart rate.
2. P-R interval: This measures the time it takes for electrical signals to travel from the atria to the ventricles.
3. QRS interval: This reflects the duration of ventricular depolarization.
4. QT interval: This includes both ventricular depolarization and repolarization times.
• The QRS Complex can be further subdivided: the initial negative deflection is termed the Q-wave. The first positive deflection is termed the R-wave. A negative deflection after the R-wave is termed the S-wave. An entirely negative QRS complex is sometimes termed a QS wave.
• A normal T-wave typically appears as a dome-shaped upward deflection.
• A normal U-wave is a small, round upward deflection that sometimes follows the T-wave.

These components and intervals help doctors understand the heart's electrical health.
In simple words: An ECG measures heart electricity, showing waves like P, QRS, and T that represent different heart actions, helping doctors check for heart problems.

🎯 Exam Tip: Clearly define each wave (P, QRS, T, U) and interval (R-R, P-R, QRS, QT), explaining the physiological event each represents for a comprehensive answer.

 

Question 3. Write an explanatory note on MRI.
Answer: Magnetic Resonance Imaging (MRI) is a powerful medical imaging technique that uses strong magnetic fields and radio waves to create detailed images of organs and soft tissues. This technique works based on the natural behavior of protons in hydrogen atoms, which are abundant in the water molecules and proteins throughout the body. Tissues with little water, like bones and teeth, do not appear well in an MRI, allowing for better contrast of soft tissues.

• MRI distinguishes between water-poor and water-abundant tissues.
• It is primarily used to study organs such as the brain and spinal cord, examine joint injuries and slipped discs, and visualize small cancerous tumors.
• The core principle of MRI is nuclear magnetic resonance (NMR).
• During an MRI scan, the patient lies in a two-meter-wide chamber surrounded by a large cylindrical electromagnet that produces a very strong magnetic field and emits radio waves.
• The strong magnetic field makes the nuclei of hydrogen atoms align, and the radio waves temporarily knock them out of alignment. When they realign, they release energy as radio signals.
• These signals are processed by a computer to produce high-contrast, thin images.
• MRI images are generally much clearer and provide better contrast than those obtained by CT scans.
• This technique can obtain images from all body axes and is particularly helpful for diagnosing and studying conditions of the brain and spinal cord, clearly differentiating between white and grey matter.
• Although MRI can be costly, its diagnostic detail makes it invaluable.

In simple words: MRI uses strong magnets and radio waves to create clear pictures of body parts, especially soft tissues, helping doctors find problems in the brain, spine, and joints without X-rays.

🎯 Exam Tip: Explain the underlying principle of NMR, the role of hydrogen atoms, and list specific diagnostic applications where MRI excels due to its high soft-tissue contrast and non-ionizing nature.

 

Question 4. What is RIA? Explain its procedure and uses.
Answer: Radioimmunoassay (RIA) is a highly sensitive biochemical technique used to measure very small concentrations of substances in a biological sample. This technique was developed by Rosalyn Yalow and Solomon Berson. It is especially useful for analyzing tiny amounts (micrograms, nanograms, or picograms) of biochemical factors that traditional methods cannot measure. RIA utilizes radioisotopes as marker molecules, giving it high specificity and sensitivity.
Procedure:

• Firstly, labelled (radioactive) and normal (unlabelled) antigen molecules are mixed with a specific antibody.
• A comparative analysis of how the labelled and unlabelled antigens compete for binding sites on the antibody is performed.
• A standard solution of varying concentrations of the substance being analyzed is used alongside the radiolabelled substance.
• This mixture is then allowed to react with antibodies until equilibrium is reached, forming antigen-antibody complexes.
• These complexes are then separated from the unbound substances, often by precipitation.
• Finally, the radioactivity of either the precipitated or supernatant parts is measured to determine the concentration of the substance.

A major benefit of RIA is that the patient is not exposed to the radioisotopic molecule directly, as the entire process is carried out outside the body (in vitro).
Uses of RIA:

• RIA is used to determine the concentration of important biological components, including vitamins (e.g., B12, folic acid), hormones (e.g., thyroxine, cortisol, estrogen), drugs (e.g., digoxin), and antigenic substances.
• It is highly valuable for diagnosing abnormalities of endocrine glands. For instance, detecting excessive hormone levels in the blood, which could be due to an overactive gland or the influence of tropic hormones, is precisely what RIA can confirm.

In simple words: RIA is a sensitive test that uses radioactive markers to measure tiny amounts of substances like hormones and vitamins in blood samples, helping diagnose various health problems without exposing the patient to radiation.

🎯 Exam Tip: When explaining RIA, describe the core principle of competitive binding, the role of radioisotopes, the steps of the procedure, and list its key applications in measuring hormones, vitamins, and drugs.