Class 12th

Every day, since 1904, the staff at the Kodaikanal Solar Observatory in Tamil Nadu have aimed their telescope at the sun, freezing the images of its disc. This data, spanning a hundred years and more, has now been digitised by astrophysicists from the Indian Institute of Astrophysics, Bengaluru, and made available to the public.

Apart from use in academic studies of long-term behaviour of the sun, the data can be used to better understand sunspot activity which impacts climate and affects telecommunication systems. It also throws light on major events in the past which had an impact on the earth's magnetic field. “From that knowledge we may understand the current and future events with greater precision. This also allows us to predict future [sunspot] activity levels with better accuracy,” says Dipankar Banerjee, IIAP, the Principal Investigator.

While 'spectroheliograms' were taken at the Kodai observatory since 1902, it was in 1909 that the data was used to discover the Evershed effect – that gases in the sunspots flowed radially outwards. The discovery by John Evershed put the KSO at par with the best observatories in the world. But its importance eventually declined as it was not upgraded or maintained. In a backhanded way, though, this turned out to be beneficial, because “the pictures had all been taken with the same instrument over the years, and this made it much easier to calibrate and digitise,” says Sudip Mandal, a PhD student who has worked on the project.

The data is unique not only in that it spans a hundred years, but that there are three sets of images, taken using different filters – White light, H-alpha and Calcium-K. It is known that the sun has a layered structure, and each of these data sets exposes a different layer.

Under white light filtering, the sun's photosphere and the sunspots are visible, while the Calcium-K light can show layers some 2,000 km above this, in the chromosphere. The H-alpha images show up layers a little above the Calcium-K images. Features called “filaments” which are related to large expulsions of material from the sun's surface can be viewed in the sets.

Opening up the digitised data has attracted international attention: Max Planck Institute, Gottingen; National Astronomical Observatories of China, Beijing and Big Bear Solar Observatory, US are interested in studying the way the sun's luminosity changes. Though the sun appears to have a steady brightness, its luminosity actually undergoes changes over time. The Big Bear Solar Observatory and the Beijing teams are interested in the H-alpha data in order to study the filaments that can be observed in those shots. Within India, groups from IUCAA, Pune; Physical Research Laboratory, Ahmedabad; and IISER, Kolkata, want to make studies.

A movie that the scientists made out of a sequence of hundreds of white light images shows how the sunspots appear and disappear periodically over an eleven-year cycle. Such movies offer immense possibilities for developing educational software, as classes of students can visually experience how the sun and the sunspots behave over the years. Just like CERN offers its data to science hobbyists, for analysis that does not require much training and yet cannot be carried out without human intervention, this data, too, could be used by science fora in India to build citizen science projects.

The data collected by 'Kodaikanal Solar Observatory' has been digitised by

Plasma is the often-forgotten part of blood. White blood cells, red blood cells, and platelets are important to body function. But plasma also plays a key role. This fluid carries the blood components throughout the body.

Plasma is the largest part of your blood. It makes up more than half (about 55%) of its overall content. When separated from the rest of the blood, plasma is a light-yellow liquid. Plasma carries water, salts and enzymes.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body that need it. Cells also put their waste products into the plasma. The plasma then helps remove this waste from the body. Blood plasma also carries all parts of the blood through your circulatory system.

Plasma is a critical part of the treatment for many serious health problems. This is why there are blood drives asking people to donate blood plasma.

 Along with water, salt, and enzymes, plasma also contains important components. These include antibodies, clotting factors, and the proteins albumin and fibrinogen. When you donate blood, healthcare providers can separate these vital parts from your plasma. These parts can then be concentrated into various products. These products are then used as treatments that can help save the lives of people suffering from burns, shock, trauma, and other medical emergencies.

 The proteins and antibodies in plasma are also used in therapies for rare chronic conditions. These include autoimmune disorders and haemophilia. People with these conditions can live long and productive lives because of the treatments. In fact, some health organisations call plasma "the gift of life."
If you want to donate plasma to help others in need, you will go through a screening process. This is to make sure your blood is healthy and safe. If you qualify as a plasma donor, you'll spend about an hour and a half at a clinic on every follow-up visit.

 During the actual blood donation process, your blood is drawn through a needle placed in a vein in one arm. A special machine separates the plasma and often the platelets from your blood sample. This process is called plasmapheresis. The remaining red blood cells and other blood components are then returned to your body, along with a little saline (salt) solution.

 People with the blood type AB are in the greatest demand for plasma donation. They make up just 2 in 50 people, their plasma is universal. This means their plasma can be used by anyone.

Plasma donation requires a commitment both in the amount of time for each donation and frequency of donation. Typically, it takes between one and three hours to donate source plasma, and plasma can be donated twice within a seven-day period. Whole blood donation takes less time—under 30 minutes—and donors donate less frequently—no more than once in eight weeks. The programs may fit into a donor's life differently at various times in the donor's life, and are equally important in helping to fulfill a vital medical need.

According to the given passage, which of the following questions is NOT answered by the author?

The passage below is accompanied by a set of questions. Choose the best answer to each question.

Plasma is the often-forgotten part of blood. White blood cells, red blood cells, and platelets are important to body function. But plasma also plays a key role. This fluid carries the blood components throughout the body.

Plasma is the largest part of your blood. It makes up more than half (about 55%) of its overall content. When separated from the rest of the blood, plasma is a light-yellow liquid. Plasma carries water, salts and enzymes.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body that need it. Cells also put their waste products into the plasma. The plasma then helps remove this waste from the body. Blood plasma also carries all parts of the blood through your circulatory system.

Plasma is a critical part of the treatment for many serious health problems. This is why there are blood drives asking people to donate blood plasma.

 Along with water, salt, and enzymes, plasma also contains important components. These include antibodies, clotting factors, and the proteins albumin and fibrinogen. When you donate blood, healthcare providers can separate these vital parts from your plasma. These parts can then be concentrated into various products. These products are then used as treatments that can help save the lives of people suffering from burns, shock, trauma, and other medical emergencies.

 The proteins and antibodies in plasma are also used in therapies for rare chronic conditions. These include autoimmune disorders and haemophilia. People with these conditions can live long and productive lives because of the treatments. In fact, some health organisations call plasma "the gift of life."
If you want to donate plasma to help others in need, you will go through a screening process. This is to make sure your blood is healthy and safe. If you qualify as a plasma donor, you'll spend about an hour and a half at a clinic on every follow-up visit.

 During the actual blood donation process, your blood is drawn through a needle placed in a vein in one arm. A special machine separates the plasma and often the platelets from your blood sample. This process is called plasmapheresis. The remaining red blood cells and other blood components are then returned to your body, along with a little saline (salt) solution.

 People with the blood type AB are in the greatest demand for plasma donation. They make up just 2 in 50 people, their plasma is universal. This means their plasma can be used by anyone.

Plasma donation requires a commitment both in the amount of time for each donation and frequency of donation. Typically, it takes between one and three hours to donate source plasma, and plasma can be donated twice within a seven-day period. Whole blood donation takes less time—under 30 minutes—and donors donate less frequently—no more than once in eight weeks. The programs may fit into a donor's life differently at various times in the donor's life, and are equally important in helping to fulfill a vital medical need.

All of the following statements weaken the author's understanding of plasma donation EXCEPT:

The passage below is accompanied by a set of questions. Choose the best answer to each question.

Plasma is the often-forgotten part of blood. White blood cells, red blood cells, and platelets are important to body function. But plasma also plays a key role. This fluid carries the blood components throughout the body.

Plasma is the largest part of your blood. It makes up more than half (about 55%) of its overall content. When separated from the rest of the blood, plasma is a light-yellow liquid. Plasma carries water, salts and enzymes.

The main role of plasma is to take nutrients, hormones, and proteins to the parts of the body that need it. Cells also put their waste products into the plasma. The plasma then helps remove this waste from the body. Blood plasma also carries all parts of the blood through your circulatory system.

Plasma is a critical part of the treatment for many serious health problems. This is why there are blood drives asking people to donate blood plasma.

 Along with water, salt, and enzymes, plasma also contains important components. These include antibodies, clotting factors, and the proteins albumin and fibrinogen. When you donate blood, healthcare providers can separate these vital parts from your plasma. These parts can then be concentrated into various products. These products are then used as treatments that can help save the lives of people suffering from burns, shock, trauma, and other medical emergencies.

 The proteins and antibodies in plasma are also used in therapies for rare chronic conditions. These include autoimmune disorders and haemophilia. People with these conditions can live long and productive lives because of the treatments. In fact, some health organisations call plasma "the gift of life."
If you want to donate plasma to help others in need, you will go through a screening process. This is to make sure your blood is healthy and safe. If you qualify as a plasma donor, you'll spend about an hour and a half at a clinic on every follow-up visit.

During the actual blood donation process, your blood is drawn through a needle placed in a vein in one arm. A special machine separates the plasma and often the platelets from your blood sample. This process is called plasmapheresis. The remaining red blood cells and other blood components are then returned to your body, along with a little saline (salt) solution.

 People with the blood type AB are in the greatest demand for plasma donation. They make up just 2 in 50 people, their plasma is universal. This means their plasma can be used by anyone.

Plasma donation requires a commitment both in the amount of time for each donation and frequency of donation. Typically, it takes between one and three hours to donate source plasma, and plasma can be donated twice within a seven-day period. Whole blood donation takes less time—under 30 minutes—and donors donate less frequently—no more than once in eight weeks. The programs may fit into a donor's life differently at various times in the donor's life, and are equally important in helping to fulfill a vital medical need.

Which one of the following comes closest in meaning to the author's understanding of plasma?

There is a sentence that is missing in the paragraph below. Look at the paragraph and decide in which blank (option 1, 2, 3, or 4) the following sentence would best fit.

Sentence: This doesn't mean you won't ever be able to access it

ChatGPT is still free to use. (1)__________. Because of the stir its advanced capabilities have made, many people are flocking to use it. (2)___________. The website operates using a server, and when too many people hop onto the server, it overloads and can't process your request. (3)___________. It just means you should try visiting the site at a later time when fewer people are trying to access the server. (4)__________. You can also keep the tab open and just refresh it periodically.

There is a sentence that is missing in the paragraph below. Look at the paragraph and decide in which blank (option 1, 2, 3, or 4) the following sentence would best fit.

Sentence: Therefore, over time, there will be more copies of these mutants than other molecules.

 (1)____________.The “RNA world” hypothesis suggests that early life may have used RNA as material for both genes and replication before the emergence of DNA and proteins. (2)___________. Once an information system can make copies of itself, natural selection kicks in. (3)_________. Some of the new copies of these molecules (which some would call “genes”) will have errors, or mutations, and some of these new mutations will improve the replication ability of the molecules. (4) __________. Some of these will accumulate further new mutations making them even faster and more abundant, and so on.