Biology (Part-IV) (Railway)

Total Questions: 50

31. Identify the water-soluble vitamin from the following. [RRB NTPC CBT-1 Exam, 07.04.2021 (Shift-I)]

(1) Vitamin A
(2) Vitamin B₁
(3) Vitamin D
(4) Vitamin E

Correct Answer: (2) Vitamin B₁

Solution:Vitamins are classified as either fat soluble (vitamins A, D. E and K) or water soluble (vitamins B and C).

• The B-group vitamins are a collection of eight water-soluble vitamins essential for various metabolic processes.

32. What is Karl Landsteiner known for? [ RRB NTPC CBT-1 Exam, 07.04.2021 (Shift-I)]

(1) Identified the Zika Virus
(2) Discovery of blood group classification
(3) Isolated the DNA
(4) Studies the nervous system

Correct Answer: (2) Discovery of blood group classification

Solution:Karl Landsteiner distinguished the main blood groups in 1900, having developed the modern system of classification of blood groups.

• He laid the foundation for the modern medical practice of blood transfusion.

33. Which cell organelle utlizes light energy during photosynthesis? [RRB NTPC CBT-1 Exam, 07.04.2021 (Shift-I)]

(1) Mitochondria
(2) Chloroplasts
(3) Ribosome
(4) Golgi body

Correct Answer: (2) Chloroplasts

Solution:Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.

• Photosynthesis in green plants takes place in chloroplasts.

• The energy of light captured by pigment molecules, called chlorophylls, in chloroplasts is used to generate high-energy electrons with great reducing potential.

34. Which action taking place in the digestive system of humans is similar to the emulsifying action of soaps on dirt? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-II)]

(1) Bile salts breaking large fat globules into smaller ones
(2) Bile juice enzymes helping in digestion of starch
(3) Bile juice providing acidic medium
(4) Bile juice providing alkaline medium

Correct Answer: (1) Bile salts breaking large fat globules into smaller ones

Solution:Fats are present in the intestine in the form of large globules which makes it difficult for enzymes to act on them.

• The bile juice secreted by the liver contains bile salts that break down large fat globules into smaller globules, increasing the surface area for the action of lipase.

• It is similar to the cleansing action of soap due to emulsification and micelle formation.

35. The presence of which bacteria is an indicator of water pollution? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-II)]

(1) Salmonella typhi
(2) Vibrio cholerae
(3) E.Coli Coliform
(4) Mycobacterium tuberculosis

Correct Answer: (3) E.Coli Coliform

Solution:The presence of coliform bacteria, such as E. coli, in surface water, is a common indicator of fecal contamination and water pollution.

• If tests suggest that coliform bacteria are present in numbers in excess of the Coliform Index, fecal contamination is suspected.

• E. coli is a member of the faecal coliform group and is a more specific indicator of faecal pollution than other faecal coliforms.

36. Which of the following parts helps in exchange of gases in plants? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-II)]

(1) Cell membrance
(2) Nucleus
(3) Stomata
(4) Guard cells

Correct Answer: (3) Stomata

Solution:In plants, the stomata helps in the exchange of gases by opening and closing of pores.

• It allows the carbon dioxide to enter and oxygen to leave the surface of a leaf.

• Stomata also regulates the loss of water vapor in transpįration.

37. Formation of urine in the kidneys Involves the given three processes in which of the following sequences? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-II)]

(1) Filtration, elimination, selective reabsorption
(2) Filtration, selective reabsorption, Elimination
(3) Selective reabsorption, filtration, elimination
(4) Selective reabsorption, elimination, filtration

Correct Answer: (2) Filtration, selective reabsorption, Elimination

Solution:Urine is formed in three main steps- glomerular filtration, reabsorption, and secretion.

• These processes ensure that only waste and excess water are removed from the body.

• Urine comprises 95 % water and 5% wastes such as ions of sodium, potassium and calcium, and nitrogenous wastes such as creatinine, urea, and ammonia.

38. Which of the following is NOT an example of asexual reproduction? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-II)]

(1) Budding
(2) Fragmentation
(3) Grafting
(4) Binary Fission

Correct Answer: (3) Grafting

Solution:Grafting is an artificial method of asexual reproduction used to produce plants combining favorable stem characteristics with favorable root characteristics.

• The stem of the plant to be grafted is known as the scion, and the root is called the stock.

• Grafting is widely used in viticulture (grape growing) and the citrus industry.

39. During adolescence, several changes occur in the human body. Which of the following changes is associated with sexual maturation only in girls? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-II)]

(1) Oily skin with pimples
(2) Growth of hair on different parts of the body
(3) Conscious of their looks
(4) Growth of mammary glands

Correct Answer: (4) Growth of mammary glands

Solution:In girls, breast budding, or the growth of mammary glands is the first sign of sexual maturation, followed closely by the start of the growth spurt.

• Shortly after that, pubic and armpit hair appears.

• Menstruation typically begins about 2 years after breast development starts.

40. Which of the following substances are selectively reabsorbed from the initial filtrate by the tubular portion of the nephron in human kidney? [RRB Group 'D' CBT Exam, 17.08.2022 (Shift-III)]

(1) Salts, glucose, fats and water
(2) Glucose, water, amino acids and proteins
(3) Glucose, water, salts and amino acids
(4) Water, glucose, salts and proteins

Correct Answer: (3) Glucose, water, salts and amino acids

Solution:Multiple substances are selectively reabsorbed from the filtrate that enters the nephron through Bowman's capsule. Most of the reabsorption takes place in the proximal convoluted tubule.

• Some of the substances that are selectively reabsorbed from the filtrate are water, slats, amino acids and glucose.

• Amino acids and glucose are both essential components of the body which is why it needs to be brought back to the blood plasma.

• From the tubule of the nephron, the glucose (CHO) and amino acids again enter the system so that they can be metabolized and used for the production of energy.

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