1. Which country has developed a green chemical method using natural fatty acids from cooking oils to recover silver from e-waste?
[A] Finland
[B] Chile
[C] Denmark
[D] India
Show Answer
Correct Answer: A [Finland]
Notes:
Researchers in Finland have developed a green chemical method using natural fatty acids from cooking oils to recover silver from electronic waste (e-waste). This comes at a time when global silver demand is rising and e-waste is becoming a major issue, especially in countries like India. E-waste includes discarded devices like computers, phones, and TVs that are outdated or broken. India is the third-largest generator of e-waste in the world, after China and the United States.
2. In the context of genetic disorders and their treatments, consider the following statements:
- Maple syrup urine disease is caused by a deficiency in the enzyme that breaks down branched-chain amino acids.
- Phenylketonuria is treated by a diet low in phenylalanine and is unrelated to maple syrup urine disease.
- Cystic fibrosis is caused by mutations in the CFTR gene and is treated with enzyme replacement therapy.
How many of the above statements are correct?
[A] Only one
[B] Only two
[C] All three
[D] None
Show Answer
Correct Answer: B [Only two]
Notes:- Maple syrup urine disease is caused by a deficiency in the enzyme that breaks down branched-chain amino acids: This is correct. MSUD results from defects in the BCKDH enzyme complex.
- Phenylketonuria is treated by a diet low in phenylalanine and is unrelated to maple syrup urine disease: This is correct. PKU is a separate genetic disorder with its own dietary management.
- Cystic fibrosis is caused by mutations in the CFTR gene and is treated with enzyme replacement therapy: This is incorrect. CF is treated with therapies like CFTR modulators, not enzyme replacement.
3. Regarding the cultivation of cannabis and its historical significance, consider the following statements:
- Cannabis has been used for textile production for thousands of years.
- The United States was the first country to legalize cannabis for recreational use.
- Hemp, a variety of cannabis, is used in the production of biodegradable plastics.
- Cannabis seeds are a rich source of protein and essential fatty acids.
How many of the above statements are correct?
[A] Only one
[B] Only two
[C] Only three
[D] All four
Show Answer
Correct Answer: C [Only three]
Notes:- Cannabis has been used for textile production for thousands of years: Correct. Historical evidence shows that cannabis fibers have been used for making textiles since ancient times.
- The United States was the first country to legalize cannabis for recreational use: Incorrect. Uruguay was the first country to fully legalize cannabis for recreational use in 2013.
- Hemp, a variety of cannabis, is used in the production of biodegradable plastics: Correct. Hemp is increasingly being used as a sustainable alternative in biodegradable plastic production.
- Cannabis seeds are a rich source of protein and essential fatty acids: Correct. They are considered a superfood due to their high nutritional value.
4. With respect to the Lewis super-acids, consider the following statements:
- These are used as catalysts in chemistry to accelerate reactions.
- These are compounds that donates an electron pair.
- It enables non-biodegradable fluorinated hydrocarbons to be converted back into sustainable chemicals.
Which of the statements given above is/are correct?
[A] Only 2
[B] Only 1 & 3
[C] Only 1 & 2
[D] 1, 2 & 3
Show Answer
Correct Answer: B [Only 1 & 3]
Notes:- ‘Lewis super-acids are derived from Lewis acids, named after the chemist, G N Lewis.
- Lewis super-acids’ are used as catalysts in chemistry to accelerate reactions.
- These are compounds that add electron pairs.
- These can be used to break strong chemical bonds and speed up reactions.
- These are highly reactive reagents, thus difficult to produce and use.
- Significance – It enables non-biodegradable fluorinated hydrocarbons (similar to Teflon) to be converted back into sustainable chemicals.
- It can possibly even convert climate-damaging greenhouse gases, such as sulphur hexafluoride into sustainable ones.
5. Consider the following statements:- Omega-3 fatty acids are polyunsaturated
- Unsaturated fats are healthier than saturated fats
- Dairy products mostly contain saturated fats
- Trans Fats generally raise both LDL and HDL
Which of the above is/are correct?
[A] 1, 3 and 4
[B] 2, 3 and 4
[C] 1, 2 and 3
[D] 1, 2, 3 and 4
Show Answer
Correct Answer: C [1, 2 and 3]
Notes:
Trans fats raise LDL (bad cholesterol) and lower HDL (good cholesterol). Saturated fats, found in dairy and red meat, are unhealthy straight-chain fatty acids without double bonds. Trans fats are unhealthy triglycerides with one or more double bonds, commonly found in baked goods and microwave popcorn. Monounsaturated fatty acids, healthier than trans and saturated fats, have one double bond and are found in peanut oil, olive oil, and nuts. Polyunsaturated fatty acids contain multiple double bonds and are present in nuts, fish, and soybean oil.
6. Which of the following is/are true for tooth decay?
- It causes severe toothache and in extreme cases results in tooth loss.
- These bacteria break down the sugars present from the left over food and release acids.
Select the correct answer from the codes given below:
[A] Only 1
[B] Only 2
[C] Both 1 and 2
[D] None of the above
Show Answer
Correct Answer: C [Both 1 and 2]
Notes:
Normally bacteria are present in our mouth but they are not harmful to us. However, if we do not clean our teeth and mouth after eating, many harmful bacteria also begin to live and grow in it. These bacteria break down the sugars present from the leftover food and release acids (see Chapter 5 to know what an acid is). The acids gradually damage the teeth. This is called tooth decay. If it is not treated in time, it causes severe toothache and in extreme cases results in tooth loss. Chocolates, sweets, soft drinks and other sugar products are the major culprits of tooth decay.
7. Which of the following acids is present in ant bites?
[A] Formic acid
[B] Malic acid
[C] Perchloric acid
[D] Nitric acid
Show Answer
Correct Answer: A [Formic acid]
Notes:
Formic acid (HCO2H) occurs naturally, most notably in some ants. The word ‘‘formic’’ comes from the Latin word for ant, formica, referring to its early isolation by the distillation of ant bodies. It is this compound that causes most of the irritation that occurs immediately following an ant bite or a bee sting.
8. Antacids are found in drugs that give relief to:
[A] Eye sight
[B] Stomach ache
[C] Acne
[D] Headache
Show Answer
Correct Answer: B [Stomach ache]
Notes:
An antacid is a substance which neutralizes stomach acidity. Antacids such as magnesium hydroxide are taken by mouth to relieve heartburn, the major symptom of gastro-esophageal reflux disease, or acid indigestion which are a few of the common terms used to describe digestive upset.
9. Which of the following statement(s) is/are correct?
- Acids are sour in taste and generate H+ ions.
- Acids are sour in taste and generate OH– ions.
- Bases are bitter in taste and generate OH– ions.
Select the correct answer from the codes given below:
[A] Only 1 and 3
[B] Only 1 and 2
[C] Only 2 and 3
[D] All of the above
Show Answer
Correct Answer: A [Only 1 and 3]
Notes:
Acids are sour in taste, turn blue litmus to red, dissolve in water to release H+ or hydrogen ions. Acids include compounds such as HCl, HCN, and H2SO4 that ionize in water to give the H+ ion. Bases produce hydroxyl ions (OH-) when mixed with water.
10. Consider the following statements:
- It is a major constituent of biological membranes, nucleic acids and cellular energy transfer systems.
- It is needed to make shells, bones and teeth.
Which of the following elements has been described in above statements?
[A] Carbon
[B] Nitrogen
[C] Phosphorus
[D] Sulphur
Show Answer
Correct Answer: C [Phosphorus]
Notes:
Phosphorus is a major constituent of biological membranes, nucleic acids and cellular energy transfer systems. Many animals also need large quantities of this element to make shells, bones and teeth.
