Genetics And Plant Breeding - Study Mode
[#516] Production of DNA from m RNA is conducted by
Correct Answer
(D) Reverse Transcriptase
Explanation
Solution: Production of DNA from m RNA is conducted by Reverse Transcriptase. Reverse transcriptase (RT), also known as RNA-dependent DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into DNA. A reverse transcriptase (RT) is an enzyme used to generate complementary DNA (cDNA) from an RNA template, a process termed reverse transcription. This enzyme can synthesize a double helix DNA once the RNA has been reverse-transcribed in a first step into a single-strand DNA.
[#517] The force responsible for the movement of water across the root in passive absorption of water operates in
Correct Answer
(B) Leaves
Explanation
Solution: The force responsible for the movement of water across the root in the passive absorption of water operates in Leaves. Passive absorption occurs when the rate of transpiration is typically higher than normal. Rapid evaporation of water from the leaves during transpiration causes a buildup of water in the xylem of the leaves, which results in a buildup of pressure. Root pressure, in plants, is the force that helps to drive fluids upward into the water-conducting vessels (xylem). It is primarily generated by osmotic pressure in the cells of the roots and can be demonstrated by the exudation of fluid when the stem is cut off just aboveground.
[#518] Kranz type of anatomy is found in or is typical of
Correct Answer
(C) C 4 -plants
Explanation
Solution: Kranz type of anatomy is found in or is typical of C 4 -plants. C 4 plants include many tropical grasses and are among the world's most important crop species (maize, sugar cane). The main role, as well as the point of the importance of the Kranz Anatomy, is that it provides the perfect site for CO 2 or carbon dioxide to be concentrated. This happens to surround the RuBisCO. This helps in the continuous fixation of the carbon dioxide that keeps the levels of CO 2 more at any given point in time. The function that makes it all the more significant is that it helps in avoiding photorespiration.
[#519] The sudden change in DNA sequence is
Correct Answer
(B) Mutation
Explanation
Solution: The sudden change in the DNA sequence is Mutation. A mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. The mutation is the ultimate source of all genetic variation, providing the raw material on which evolutionary forces such as natural selection can act.
[#520] Pusa Arunima and Pusa Surya are new varieties of
Correct Answer
(A) Mango
Explanation
Solution: Pusa Arunima and Pusa Surya are new varieties of mangoes. Pusa Arunima is a hybrid, derived from the cross between Amrapali and Sensation. The plants are semi-vigorous and are suitable for closer planting (6 m × 6 m). It is a regular bearer and starts bearing after 4 th year of planting. It is suitable for domestic market. It can also be accepted in the international markets, because of its attractive red peel colour, fibreless pulp, mild flavour, medium TSS, excellent sugar: acid blend and long shelf-life. It was released in 2002. Pusa Surya is a regular bearer variety. Its plants are semi-vigorous. Therefore, it is suitable for closer planting (6 m × 6 m). It is less susceptible to mango malformation in comparison to Amrapali and other commercial cultivars of northern India. It ripens by 3 rd week of July. It is suitable for domestic and international markets. It was released in 2002.