All Free Biology MCQs with Answers

• A. PCR and RAPD
• B. Northern blotting
• C. Electrophoresis and HPLC
• D. Microscopy.

Explanation: Clonal propagation can be characterized by PCR and RAPD. The polymerase chain reaction (PCR) technique generates microgram (ug) quantities of DNA copies (up to billion copies) of the desired DNA (or RNA) segment, present even as a single copy in the initial preparation, in a matter of few hours. RAPD stands for Random Amplification of Polymorphic DNA. It is a type of PCR, but the segments of DNA that are amplified are random. No knowledge of the DNA sequence for the targeted gene is required, as the primers will bind somewhere in the sequence, but it is not certain exactly where. Its resolving power is much lower than targeted, species specific DNA comparison methods, such as short tandem repeats.

• A. Apical meristem only
• B. Palisade parenchyma
• C. Both apical and axillary meristems
• D. Epidermis only

Explanation: Meristem is a localized group of cells, which are actively dividing and undifferentiated but ultimately giving rise to permanent tissue. Although the plant is infected with a virus, yet the meristem is free of virus. Therefore, meristem can be removed and grown in vitro to obtain virus free plants. Cultivation of axillary or apical shoot meristems is called meristem culture. The apical or axillary meristems are generally free from virus.

• A. Evaluation and selection of parents
• B. Germplasm collection
• C. Selection of superior recombinants
• D. Cross-­hybridisation among the selected parents.

Explanation: Germplasm of any crop species consists of (i) cultivated improved varieties, (ii) improved varieties that are no more in cultivation, (iii) old local or 'desi' varieties, (iv) pure lines and (v) wild species related to the crop species.

• A. Genetically uniform population identical to the original parent
• B. Homozygous diploid plants
• C. New species
• D. Variants through picking up somaclonal variations.

Explanation: Plant tissue culture, also called micro­ propagation, is the growth of plant cells outside the plant body in a suitable culture medium which contains a mixture of nutrients in solid or liquid form, under controlled environmental conditions. Tissue culture technique is based on the totipotent nature of plant cells or phenomenon of totipotency i.e., each and every plant cell has an inherent capacity to develop into a complete plant. The entirely vegetatively produced descendants of somatic cells are collectively called clone. They are genetically identical to their parents.

• A. 2, 6 dichlorophenol indophenols
• B. 2, 3, 5 triphenyl tetrazolium chloride
• C. DMSO
• D. Safranin

Explanation: Viability of seeds can be known by two methods: (i) ability to germinate, (ii) testing their ability to respire. All viable seeds respire. This can be tested by immersing a section of seed containing the embryo in 0.1% solution of triphenyl tetrazolium chloride. The viable embryo will turn pink due to conversion of colorless triphenyl tetrazolium chloride into insoluble colored dye called triphenyl formazone due to reduction.

• A. The pattern of development of a somatic embryo is comparable to that of a zygotic embryo.
• B. Somatic embryos can develop from microspores.
• C. Somatic embryo is induced usually by an auxin such as 2, 4­D.
• D. A somatic embryo develops from a somatic cell.

Explanation: Somatic embryos develop from somatic cells. Their development is comparable to that of a zygotic embryo. They are just like a normal embryo except that their development is induced from a diploid somatic cell. Somatic embryo culture is induced by a high concentration of an auxin. Microspores are haploid cells that do not give rise to somatic embryo.

• A. Somatic hybridization­-Fusion of two diverse hybridization cells
• B. Vector DNA-Site for tRNA synthesis
• C. Micropropagation­-in vitro production of plants in large numbers
• D. Callus-Unorganised mass of cells produced in tissue culture.

Explanation: Vectors are DNA molecules that can carry a foreign DNA segment and replicate inside the host cell. They are used in recombinant DNA technology.

• A. Bark
• B. Vascular tissue
• C. Meristem
• D. Node

Explanation: Meristem is a localized group of cells, which are actively dividing and undifferentiated but ultimately giving rise to permanent tissue. Although the plant is infected with a virus, yet the meristem is free of virus. Therefore, meristem can be removed and grown in vitro to obtain virus free plants. Cultivation of axillary or apical shoot meristems is called meristem culture. The apical or axillary meristems are generally free from virus.

• A. 1960's
• B. 1970's
• C. 1980's
• D. 1950's.

Explanation: The development and usage of several high yield varieties of wheat and rice, better irrigation facilities, fertilizer application, weed, pest and pathogen control and better agricultural management in the 1960s increased the yields per unit area. This phase is often called the Green Revolution. In India, it was witnessed during the mid-1960s. Norman E. Borlaug is known as the Father of the Green Revolution as he developed the semi­dwarf varieties of wheat. In 1963, many lines like Sonalika and Kalyan Sona were selected from these and introduced all over India. Semi­-dwarf varieties of rice were developed from IR-­8 at International Rice Research Institute (IRRI), Philippines and Taichung Native ­-1 from Taiwan which were introduced in 1966 to India. Dr. M.S. Swaminathan, pioneer mutation breeder produced Sharbati Sonora, a variety of wheat by mutation, which is responsible for the Green Revolution in India. Dr. Swaminathan is called the Father of Green Revolution in India.

• A. Herbarium
• B. Germplasm
• C. Gene library
• D. Genome.

Explanation: The entire collection (of plants/seeds) having all the diverse alleles for all genes in a given crop is called germplasm collection.