11. Which of the following is the largest cell in mammalian blood?
[A] Erythrocytes
[B] Monocytes
[C] Lymphocytes
[D] Basophils
Show Answer
Correct Answer: B [Monocytes]
Notes:
Monocytes are a type of white blood cell that fights off bacteria, viruses and fungi. Monocytes are the biggest type of white blood cell in the immune system. Originally formed in the bone marrow, they are released into our blood and tissues. When certain germs enter the body, they quickly rush to the site for attack.
12. Niacin is the chemical name of which vitamin?
[A] Vitamin B1
[B] Vitamin B3
[C] Vitamin B2
[D] Vitamin C
Show Answer
Correct Answer: B [Vitamin B3]
Notes:
The chemical name of Vitamin B3 is Niacin which is a water soluble vitamin. It is an important nutrient. In fact, every part of your body needs it to function properly. As a supplement, niacin may help lower cholesterol, ease arthritis and boost brain function, among other benefits.
13. Which of the following is responsible for giving colour to human skin?
[A] Haemoglobin
[B] Melanin
[C] Luciferin
[D] Flavonoids
Show Answer
Correct Answer: B [Melanin]
Notes:
Melanin is a pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes.
14. Due to which of the following reasons the scratching eases itching? (UPSC Prelims 1993)
[A] it removes the outer dust in the skin
[B] it kills the germs
[C] it stimulates certain nerves which direct the brain to increase the production of antihistaminic chemicals
[D] it suppresses the production of enzymes which cause itching
Show Answer
Correct Answer: C [it stimulates certain nerves which direct the brain to increase the production of antihistaminic chemicals]
Notes:
Scratching helps to relieve an itch because it reduces the sensations of pain sent to the brain, a new study has found. Scientists found that skin cells in that part of the body tended to respond more to itchy substances than those in other areas.
15. Which vitamin is also called as retinol?
[A] Vitamin A
[B] Vitamin C
[C] Vitamin D
[D] Vitamin K
Show Answer
Correct Answer: A [Vitamin A]
Notes:
Vitamin A is also called as retinol deficiency of which results in xeropthalmia. Chemical formula for Vitamin A is C20H30O.
16. Which is the world’s smallest bird?
[A] Red-cheeked Cordon-Bleu
[B] Costa’s Hummingbird
[C] Bee Hummingbird
[D] Goldcrest
Show Answer
Correct Answer: C [Bee Hummingbird]
Notes:
Bee Hummingbird is the smallest bird in the world. It is only 2 to 2.4 inches long and weighs 0.056 to 0.071 ounces. This bird is also known as zunzuncito or Helena Hummingbird. This bird is native to Cuba. It is endemic to the entire Cuban archipelago. It is “Nearly Threatened” bird species according to IUCN Red List of Threatened Species.
17. Which branch of biology is known for the study of developmental process of organisms?
[A] Genetics
[B] Evolution
[C] Histology
[D] Heredity
Show Answer
Correct Answer: B [Evolution]
Notes:
In branch of biology, the study of developmental process of organisms is known as Evolution. The theory of evolution is based on the idea that all species are related and change slowly over time. Charles Darwin’s theory of evolution states that evolution occurs by natural selection.
18. Which branch of biology is deal with the study of seeds?
[A] Embryology
[B] Spermatology
[C] Gerontology
[D] Histology
Show Answer
Correct Answer: B [Spermatology]
Notes:
The study of seeds is known as spermatology. It involves the study in terms of morphology, characteristics and interactions with the environment.
19. Which of the following is involved in the synthesis of phospholipids?
[A] Mitochondria
[B] Cytoplasm
[C] Endoplasmic Reticulum
[D] Smooth Endoplasmic Reticulum
Show Answer
Correct Answer: D [Smooth Endoplasmic Reticulum]
Notes:
The smooth endoplasmic reticulum serves as part of many metabolic processes. It synthesizes lipids, phospholipids on the plasma membrane and steroids.
20. Which of the following compounds is not found in protein?
[A] Carbon
[B] Hydrogen
[C] Sulfur
[D] Helium
Show Answer
Correct Answer: D [Helium]
Notes:
Protein is made up of amino acids and is the main bodybuilding biomolecule of our body. 75% of the body is made up of protein, The main compounds of protein are carbon, hydrogen, oxygen, nitrogen, and sulfur.
