Biology

271. Which of the following induces souring of milk?

1. Acetic Acid
2. Citric Acid
3. Ascorbic Acid
4. Lactic Acid

Option “4” is correct
Milk contains a sugar called lactose. It also contains harmless bacteria called lactobacillus, which uses lactose for energy and creates lactic acid as a by-product. It is the lactic acid which makes milk taste sour.
272. Which of the following is essential to regulate the heart beat?

1. Iron
2. Sulphur
3. Potassium
4. None of these

Option “3” is correct
Potassium (K) plays a role in every heart beat. A hundred thousand times a day, it helps trigger the heart to squeeze blood through the body. It also helps your muscles to move, nerves to work and kidneys to filter blood. Phosphorus is good for the development of bones whereas iron deficiency leads to anaemia.
273. Which hormone controls the quantity of urine from kidney?

1. TSH
2. ACTH
3. FSH
4. ADH

Option “4” is correct
ADH (Antidiuretic) hormone is released form pituitary gland which is responsible for controlling secretion of urine from kidney.
274. Cobalt-60 is generally used in radiation treatment because it ejects–

1. α rays
2. β rays
3. γ rays
4. X-rays

Option “3” is correct
Coblat-60 is a synthetic isotope of cobalt. Gamma rays are ejected after the bombing of neutrons on cobalt. This is the reason, why it is used in radiation treatment.
275. The thymus gland produces a hormone called –

1. Thyroxine
2. Thymosin
3. Thyronine
4. Calcitonin

Option “2” is correct
The thymus gland is located behind sternum and between lungs. Thymosin is the hormone of the Thymus. Thymosin stimulates the development of T cells.
276. The body of all complex animals consist of only _______ basic types of tissue(s).

1. 4000
2. 400
3. 40
4. 4

Option “4” is correct
The term tissue is used to describe a group of cells found together in the body. There are four types of tissues in complex animals,they are connective, muscle, nervous, and epithelial.
277. Which is the longest bone in human body?

1. Febula
2. Tibia
3. Stapes
4. Femur

Option “4” is correct
Femur, or thighbone, is the largest bone in your body. The head of femur fits into your hip socket and the bottom end connects to knee. The two bones beneath knee that make up shin are your tibia and fibula. Your upper and lower legs are connected by a hinge joint.
278. Which among the following carries impure blood from human heart?

1. Aorta
2. Pulmonary vein
3. Pulmonary arteries
4. Vena Cava

Option “3” is correct
The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
279. UV rays coming from Sun, majorly causes which cancer?

1. Lungs cancer
2. Liver cancer
3. Mouth cancer
4. Skin cancer

Option “4” is correct
Ultraviolet (UV) radiation from the sun or sunbeds is the main cause of skin cancer.
280. Which of the following is the largest mammal?

1. Whale
2. Rhinoceros
3. Elephant
4. Human

Option “1” is correct
Blue Whale is the largest known mammal