Plant tissue culture MCQ

Ans: b) in vitro maintaining and growing cells

Explanation: Plant tissue culture is the technique of in vitro maintaining and growing cells, tissues, organs, etc.; and their differentiation on an artificial medium under aseptic conditions inside suitable containers. It depends on the potential of plant cells called totipotency which imparts capability to the cells to grow and differentiate. Basic requirements for plant tissue culture are washing and storage facilities, culture media, culture room, incubator, etc.

Ans: b) Haberlandt

Explanation: Tissue culture technique was first practised by German botanist Gottlieb Haberlandt in 1902. He was able to culture isolated and fully differentiated cells in a nutrient medium containing glucose, peptone and Knop’s salt solution. But he failed to induce cell division in the culture. Later Hannig (1904) and Robbins (1922) solved the problem. Today, tissue culture is the fundamental bedrock on which almost the entire application of biotechnology, genetic engineering depends.

Ans: d) Skoog

Explanation: Embryoids are non-zygotic embryo-like structures produced in vitro culture and have the ability to form full adult plants. Discovery of formation of embryoids or somatic embryos is credited to Steward, Halperin and Wetherell. They studied somatic embryos in young anthers of Datura. Whereas Skoog and Miller found that growth and morphogenesis were controlled by hormones such as auxin and cytokinin.

Ans: b) It’s a part of plant or plant grown in a test tube

Explanation: Plant parts that are excised from the original and are used for initiating a culture in septic conditions are known as explants. Whole plant or parts of it can be regenerated from explants in suitable nutrient culture by controlling the nutrients, temperature, hormones, etc. Explants must be sterilised before putting them into the culture medium. Explants must be chosen from the healthy part of the plant and must be infection-free, to yield good results.

Ans: a) False

Explanation: The technique of producing thousands of genetically identical plants with desirable traits from a given sample plant or plant cells through tissue culture is called micropropagation. Whereas, the capacity to generate a whole new plant from any cell is due to totipotency. Totipotency in the inherent capacity of all plant cells and micropropagation is a type of technique in tissue culture that uses the totipotency of plant cells.

Ans: c) It should provide a carbon source

Explanation: Plants cells in culture lack autotrophic ability and therefore need external carbon for energy. So, an essential requirement of an artificial medium in which explant is being regenerated is that the medium must provide a carbon source such as sucrose and additionally inorganic salts, amino acids, vitamins and plant hormones like auxins, cytokinin, etc. Sometimes artificial lights, shakers are also needed.

Ans: d) Plants which are genetically identical to the source plant

Explanation: There are various copies of plants of tissue culture which are similar to the original plant by which they were grown and they are called somaclones. Many crucial food crops like tomato, banana and apple, etc., are produced on a commercial scale using this method. Soma clones are different from clones since clones are produced by asexual reproduction.

Ans: c) Meristem

Explanation: Stem, root and leaves are likely to be infected by virus but meristematic areas like apical meristem and axillary meristem are likely to be free of the virus because the cell division in meristematic region is faster than the rate of virus genetic material replication and multiplication. So, viruses being dependent on host cells and their cellular components can’t survive.

Ans: b) apple

Explanation: Since meristems are generally not infected by diseases, even rest parts are infected, meristems are used for recovery of healthy plants from diseased plants. Hence, we can remove the meristem and grow it in vitro to regenerate virus-free plants. So far, scientists succeeded in culturing meristems of banana, sugarcane and potato. Apple meristem culture is yet to be developed.

Ans: b) Plant cell – cell wall

Explanation: Protoplasts without a cell wall are called plant cells. Protoplasts are obtained after digesting their cell walls with enzymes. Protoplast is typically quite unstable structures since without structural integrity it is lost. Protoplast culture requires special care so the cells don’t break. Protoplast is developed for introducing foreign genetic elements easily into them during genetic engineering.

Ans. c) 2 and 3

Explanation: The growth of plants is indefinite. Plants grow throughout their life with the help of certain tissues located in certain regions of the body. i.e., meristematic tissues. The structural organization of plants is not complex as compared to that of animals. Plant tissues are also not much complicated as that animal tissues.

Ans. b) aerenchyma 

Explanation: In aquatic plants (hydrophytes) large air cavities are present in the parenchymatous tissue. These cavities store gases and provide buoyancy to aquatic plants to help them float. Such parenchyma are called aerenchyma.

Ans. b) Collenchyma

Explanation: Collenchyma is a living cell that gives mechanical strength to the plant.

Ans. b) Meristem

Explanation: Meristems are the sites or regions within the plant body where the formation of new meristematic cells takes place. For example, root and shoot tips.

Ans. a) Xylem

Explanation: Xylem (wood) is a complex permanent tissue forming a part of the vascular bundle. It is primarily responsible for the conduction of water and solutes from the roots up to the top of the plant. It is composed of cellular structures, such as tracheids, vessels, xylem parenchyma, and xylem fibers.

Ans. b) Meristem

Explanation: A meristem is a tissue in plants consisting of undifferentiated cells (meristematic cells). It is found in specific regions of a plant body where constant cell division takes place. 

Ans. b) Lateral meristem

Explanation: Lateral meristem brings about the outward growth of a plant by increasing its width and girth. Outward growth results in the thickness of the plant.

Ans. a) Collenchyma

Explanation: Collenchyma is a living tissue of the primary body. The cells are thin-walled but possess thickenings of cellulose and pectic substances at the corners where a number of cells join together. The tissue provides flexibility to soft aerial parts (e.g., leaves, young stems) of plants so that they can bend without breaking. The cells are compact and the inter-cellular spaces are absent.

Ans. d) Epidermis

Explanation: A xerophyte is an organism, which is able to survive in an ecosystem with little or no water (or moisture). To reduce transpiration the epidermal cells of xerophytes (plants) secrete a waxy (fatty) water-resistant layer of cutin.

Ans. d) Parenchyma

Explanation: Parenchyma cells store biochemicals. These are the familiar edible parts of plants. E.g., carbohydrates in a potato, ear of corn. These cells also store salts, pigments, organic acids, fragment oil, etc. E.g., Lemons and oranges store citric acid.