Daily Quiz – 19th Apr 2024

Exp) Option b is the correct answer

Genes are located on the DNA present in the chromosome. Thus, DNA is a carrier of genetic information. A number of genetic/chromosomal disorders in human beings have been traced to the inheritance of changed or altered genes or chromosomes.

Pair 1 is correct: Sickle cell anaemia is one of a group of inherited disorders and it affects the shape of red blood cells, which carry oxygen to all parts of the body. Red blood cells are usually round and flexible, so they move easily through blood vessels. These sickle shaped RBCs become rigid and sticky, which can slow or block blood flow.

Pair 2 is incorrect: Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small packages of genes in the body and they determine how a baby’s body forms and functions. People with Down syndrome usually have a low IQ and are slower to speak than others.

Pair 3 is correct: Thalassemia is a genetic disorder due to which a patient cannot make enough haemoglobin found in Red Blood Cells (RBC’s). It affects the clotting of blood and leads to anaemia and patients also require blood transfusions every two to three weeks to survive.

Pair 4 is incorrect: Duchenne Muscular Dystrophy (DMD) is not caused due to the mutation in sperm or egg cells. It is marked by progressive muscle degeneration and weakness due to alterations of a protein called dystrophin that helps keep muscle cells intact. It is the most common and fatal type of muscular dystrophy,

Exp) Option b is the correct answer.

Gastrin is not a digestive enzyme in the human system. It is a hormone secreted by specialized cells in the stomach (G cells) and the duodenum in response to the presence of food. Gastrin plays a role in regulating gastric acid secretion, gastric motility, and the growth of gastric mucosa. While it influences digestive processes, it is not an enzyme involved in the actual breakdown of food components like the other options (Trypsin, Ptyalin, and Pepsin).

1) Trypsin is a digestive enzyme produced by the pancreas. It plays a crucial role in breaking down proteins into smaller peptides and amino acids, facilitating their absorption in the small intestine.

2) Ptyalin, also known as salivary amylase, is an enzyme found in saliva. It starts the digestion of carbohydrates by converting starches into simpler sugars like maltose in the mouth.

3) Pepsin is a gastric enzyme produced by the stomach lining. It’s responsible for breaking down proteins into smaller peptide fragments, aiding in the digestion of dietary proteins in the stomach’s acidic environment.

Exp) Option c is the correct answer.

Living beings constantly require energy to perform various functions. Respiration breaks down glucose and other nutrients from food into a molecule called ATP (adenosine triphosphate). The main purpose of ATP is to store and transport energy within the cell for various cellular functions and processes. Hence respiration aids in the transport of energy throughout the body.

While aerobic respiration takes place in the presence of oxygen, the anaerobic respiration takes place in the absence of oxygen.

Option 1 is correct: Yeast is both aerobic and anaerobic, meaning it can survive and thrive both in the presence and absence of oxygen. In the presence of oxygen, they undergo aerobic respiration for more energy, but when oxygen is absent, they switch to anaerobic fermentation (producing alcohol or CO2).

Option 2 is correct: Lactobacillus bacteria can also survive in the absence of oxygen. In fact, these bacteria are obligate anaerobes, meaning they absolutely require the absence of oxygen for their metabolism. Oxygen is toxic to them, and they die in its presence.

Option 3 is incorrect: Earthworms require oxygen to survive, without oxygen they suffocate and die. They breathe through their skin, absorbing oxygen from the air in the soil.

Option 4 is correct: Certain parasites can survive in environments with low or no oxygen. For example Platyhelminthes (flatworms) exhibit both aerobic and anaerobic metabolism depending on the availability of oxygen in their environment, thus respire and survive without oxygen.

Exp) Option c is the correct answer.

Antioxidants play a crucial role in maintaining health and promoting longevity by neutralizing harmful free radicals in the body. Free radicals are highly reactive molecules produced during metabolism, and they can damage cells and DNA, contributing to various diseases and the aging process. Antioxidants counteract this damage by donating electrons to stabilize free radicals, preventing cellular harm. Thus, a diet rich in antioxidants, primarily found in fruits and vegetables, helps protect cells, reduce oxidative stress, and supports overall health and longevity.

Exp) Option c is the correct answer.

The immune system plays a pivotal role in safeguarding the body against various pathogens and foreign invaders. Among the key players in this defense mechanism are B-cells and T-cells, two types of lymphocytes (white blood cells).

Statement 1 is correct: B-cells are responsible for producing antibodies, which are proteins that play a crucial role in the immune response by binding to and neutralizing pathogens such as viruses and bacteria. T-cells, on the other hand, do not themselves produce antibodies but contribute to the immune response by recognizing and attacking infected cells.

Statement 2 is correct: Vaccines are designed to stimulate the immune system, and many vaccines induce responses from both B-cells and T-cells. B-cells are activated to produce antibodies, while T-cells are triggered to recognize and eliminate infected cells. Thus, by stimulating response from both the cells, vaccination enhances the immune system's ability to effectively combat future infections.