Railway Science (Biology – Cell : Basic Unit of Life) (Part-II)

Total Questions: 45

31. ______is the source of information necessary to make proteins in the cell. [RRB Group D 13/12/2018 (Morning)]

Correct Answer: (a) cellular DNA
Solution:

Cellular DNA, or deoxyribonucleic acid, carries the genetic instructions that determine the structure and function of all proteins in the cell. This information is transcribed into RNA (cellular RNA), which then serves as the template for protein synthesis.

32. The girth of the stem or root in plants increases due to: [RRB ALP Tier - I (09/08/2018) Afternoon]

Correct Answer: (c) Lateral meristem
Solution:

Meristematic tissue - Growing regions of the plants. Types : Apical Meristems - These tissues are found in root and stem apex and it is responsible for the initial growth of the plants.
Intercalary meristems - found at the base of nodes or internodes in some plants. They are responsible for the growth in the intercalary regions, such as the elongation of grass blades at their base.

33. What is a tissue ? [RRB ALP Tier - I (09/08/2018) Evening]

Correct Answer: (b) Cells which are similar in origin, form and function
Solution:

Groups of tissues make organs. The study of tissue - Histology. Histopathology - Study of disease-related tissue. There are 4 basic types of tissue: Connective tissue, Epithelial tissue, Muscle tissue and Nervous tissue.

34. The process of taking up a permanent shape, size and function to form a permanent tissue is called: [RRB ALP Tier - I (10/08/2018) Evening]

Correct Answer: (a) differentiation
Solution:

Differentiation is the natural process through which a cell with less specificity develops and matures to become more distinct in terms of form and function. Examples - Nerve cells, muscle cells and blood cells that develop through the regulation of specific genes and molecular signals during the development of an organism. Calcification happens when calcium builds up in body tissue, blood vessels or organs. Calcium is transported through the bloodstream. It is present in every cell.

35. In which of the following tissues are the cells living, elongated and irregularly thickened at the corners? [RRB ALP Tier - I (13/08/2018) Morning]

Correct Answer: (a) Collenchyma
Solution:

Collenchyma - Elongated living cell with thick cell wall at corner due to cellulose and pectin; Located at the base of leaf, branches, stems; Function - Flexibility to various parts.
Parenchyma - Living cell with thin cell wall and intercellular space; Located at all parts; Function - To store and absorb food. Sclerenchyma - Dead and fibrous cells with tapering ends, cell wall contains lignin;
Location - It is present in stems, in the veins of leaves and in the hard covering of seeds; Function - Give strength and rigidity to the parts of the plants.

36. A fungal cell wall is made of: [RRB ALP Tier - I (13/08/2018) Evening]

Correct Answer: (a) chitin
Solution:

Fungal cell wall has a dynamic structure which protects the fungi from environmental stress. Feature - Biosynthesis. Major Composition: Glucans, Glycoproteins and Chitin.
Cellulose is a Complex carbohydrate consisting of oxygen, carbon and hydrogen. It is to provide shape and rigidity to the cell wall of a plant.
Lignin - Complex oxygen-containing organic polymer that, with cellulose, forms the chief constituent of wood.
Hemicellulose - Important component of plant cell walls, which is mainly used in biofuels and bioproducts.

37. What is the name of the point at which the chromatids are attached in a chromosome? [RRB ALP Tier - I (13/08/2018) Evening]

Correct Answer: (a) Centromere
Solution:

Centromere - Links a pair of sister chromatids together during cell division. Centrosome - This cell organelle is only found in animal cells and it is composed of two centrioles. It also regulates the cell cycle.
Nucleosome - A structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones.
Gene - Fundamental unit of heredity. It is a segment of DNA that has information coded in it in the form of a nucleotide sequence.

38. Name the stage of mitosis during which the chromosomes of a dividing cell lies at the equatorial plate? [RRB ALP Tier - I ( 14/08/2018 )Afternoon]

Correct Answer: (a) Metaphase
Solution:

Metaphase - It is the second stage of cell division, between prophase and anaphase, during which the chromosomes become attached to the spindle fibers. Prophase, the first stage of cell division, where chromosomes thicken, condense and become visible.
Anaphase, the third stage of cell division occurs when the spindle separates during reproduction. Telophase is the final stage in both meiosis and mitosis in a eukaryotic cell. Cell discovered by Robert Hooke in 1665, Robert Brown Discovered cell nucleus.

39. Which permanent tissue makes a plant hard and stiff? [RRB ALP Tier - I (17/08/2018) Morning]

Correct Answer: (a) Sclerenchma
Solution:

Sclerenchyma - These are composed of dead cells, which have thickened walls containing lignin and cellulose. Function of Sclerenchyma - Provide mechanical support and strength to the plants, form protective coverings around nuts and seeds.
Functions of other tissues: Aerenchyma - facilitate the movement of gases (O₂ , CO₂ , ethylene, and methane) in and out of tissues. Parenchyma - store food and provide turgidity to organs. Collenchymas - Provides flexibility to the petiole, leaf veins, and stem of young plants.

40. ______ are the carriers of heredity material. [RRB ALP Tier - I (20/08/2018) Morning]

Correct Answer: (d) Genes
Solution:

Genes (section of DNA that provides information for one protein) - Functional unit of heredity which is transferred from a parent to offspring and it is made up of DNA. William Bateson coined the term genetics in 1905.
Wilhelm Johannes was the first one who coined the term “GENE” in 1909. Replication of genes is essential for cell division. Function of Gene - Control the functions of DNA and RNA, control the structure and metabolism of the body.