The question asks about the oxygen-carrying capacity of haemoglobin in 100 mL of oxygenated blood. This is a standard physiological value that competitive exam aspirants are expected to know.
This value, approximately 20 mL of oxygen per 100 mL of blood, represents the total oxygen content when haemoglobin is fully saturated. However, the question asks for the oxygen carrying capacity of haemoglobin, which is often rounded to a simpler, more memorable figure in the context of competitive exams. While 20 mL is the precise calculated value, option C (5 mL) is incorrect. Let's re-evaluate the question's intent.
A common misconception or a simplified figure often quoted in textbooks for the oxygen content of arterial blood is around 20 mL per 100 mL of blood. However, the options provided are much lower. Let's re-examine the options and the phrasing.
The question asks for the "oxygen carrying capacity of haemoglobin in 100 mL of oxygenated blood." This usually refers to the amount of oxygen transported by haemoglobin. Given the options, there might be a specific context or a common approximation being tested. Let's reconsider the options.
Upon reviewing standard physiological values, the oxygen content of arterial blood (which is oxygenated) is indeed around 20 mL per 100 mL of blood. If the options are significantly lower, there might be a misunderstanding of the question or the options are incorrect. However, if we assume the question is looking for a specific, perhaps simplified, value related to oxygen transport, let's look at the options again.
Let's re-evaluate the question. The oxygen carrying capacity of 100 mL of blood is indeed around 20 mL. None of the options reflect this. There might be a typo in the question or options, or it's referring to something else. However, if we are forced to choose from the given options, and assuming there's a common approximation or a specific context, let's consider the options.
Let's assume there's a typo in the question and it meant something else, or the options are extremely simplified. If we consider the amount of oxygen released to tissues, it's typically around 5 mL per 100 mL of blood. This is the A-V oxygen difference. However, the question asks for the *carrying capacity* in oxygenated blood, not the amount released.
Let's reconsider the average oxygen content in 100 mL of arterial blood. It is approximately 20 mL. If the options are 1, 3, 5, 7 mL, then none of them are correct based on the standard physiological value of 20 mL. However, in some simplified contexts or older textbooks, a value around 5 mL might be mentioned in relation to oxygen *utilization* or *difference* rather than total capacity.
Let's assume the question is flawed or is referring to a very specific, perhaps outdated, or simplified context. If we must choose, and knowing that the actual value is around 20 mL, let's check if any option is a common distractor or a misremembered value.
Let's assume the question is asking for the amount of oxygen *released* to the tissues from 100 mL of blood, which is approximately 5 mL (the arterio-venous oxygen difference). While the question asks for "carrying capacity in oxygenated blood," which is total content, sometimes questions can be ambiguously phrased. If the options are so low, it's highly probable that it refers to the oxygen *released* or *utilized* by tissues, rather than the total carrying capacity.
Given the options, and the fact that 5 mL is a significant physiological value (the amount of oxygen delivered to tissues per 100 mL of blood), it's the most plausible answer if the question is interpreted as "how much oxygen is typically *unloaded* from 100 mL of oxygenated blood to the tissues?"
However, if we strictly interpret "oxygen carrying capacity of haemoglobin in 100 mL of oxygenated blood" as the total oxygen content, the value is approximately 20 mL. Since 20 mL is not an option, and 5 mL represents the amount of oxygen delivered to tissues from 100 mL of blood, it is often a related figure discussed in the context of oxygen transport.
Let's assume the question is indeed asking for the typical amount of oxygen *released* from 100 mL of blood to the tissues, which is about 5 mL.
Therefore, if we consider the amount of oxygen that 100 mL of blood typically delivers to the tissues (arteriovenous oxygen difference), it is approximately 5 mL. This is a common physiological value, and given the options, it is the most likely intended answer, despite the phrasing "carrying capacity."
C) 5 mL — While the total oxygen-carrying capacity of 100 mL of fully oxygenated blood is approximately 20 mL, the options provided are much lower. In the context of oxygen transport, 5 mL is a significant physiological value, representing the average amount of oxygen released by 100 mL of blood to the tissues under resting conditions (the arterio-venous oxygen difference). It is plausible that the question, despite its phrasing, is referring to this value, or there is a simplification/misphrasing in the question itself. In competitive exams, sometimes the closest physiologically relevant value among the options is chosen.
The question asks about the primary mechanism for carbon dioxide transport in the blood. To answer this, we need to recall the different forms in which carbon dioxide is carried from tissues to the lungs and identify which form accounts for the largest proportion.
B) As bicarbonate — Approximately 70% of the carbon dioxide transported in the blood is in the form of bicarbonate ions (\(\text{HCO}_3^-\)). This is the most significant mechanism for \(\text{CO}_2\) transport.
The question asks to identify the brain center responsible for regulating respiratory rhythm. This requires knowledge of the different parts of the brain and their primary functions, specifically those related to vital involuntary processes like breathing.
D) Medulla — The medulla oblongata contains the primary respiratory rhythm-generating centers (dorsal and ventral respiratory groups) that establish the basic rhythm of breathing.
This question asks about the physiological response to an increase in partial pressure of carbon dioxide (pCO2) in the blood. This is a fundamental concept in respiratory physiology, specifically related to the regulation of breathing.
C) Respiratory rate increases — An increase in pCO2 in the blood makes the blood more acidic. This change is detected by chemoreceptors, which then stimulate the respiratory center in the brain to increase the rate and depth of breathing. This increased ventilation helps to remove excess CO2 from the body, thus normalizing blood pH.
The question asks about the importance of Pneumococcal Conjugate Vaccines (PCV) in India. We need to evaluate each statement provided and determine its correctness in the context of PCVs.
Based on the evaluation, statements 1 and 2 are correct, while statement 3 is incorrect.
Correct Option: B) 1 and 2 only