Genetics And Plant Breeding - Study Mode

[#311] The term recurrent selection was coined by
Correct Answer

(D) Hull (1945)
(E) Hull (1945)

Explanation

Solution: The term recurrent selection was coined by Hull (1945). It was HULL who first used the term “recurrent selection” in 1945. He proposed a breeding method that was termed "recurrent selection for specific combining ability." Recurrent selection means repeated cycles of selection and breeding aimed at the gradual genetic improvement of a few key traits in a single species.

[#312] Inhibitors to mRNA synthesis (Transcription) are
Correct Answer

(D) All of the above

Explanation

Solution: Inhibitors to mRNA synthesis (Transcription) are Actinomycin-D, Rifampicin, also 5-Bromouracil. Transcription inhibition is accompanied by notable changes in the biochemical properties of nuclear proteins such as histones and hnRNPs. Actinomycin D is a transcription inhibitor that intercalates into DNA. Actinomycin D forms a very stable complex with DNA, preventing the unwinding of the DNA double-helix, thus inhibiting the DNA-dependent RNA polymerase activity. Rifamycin inhibits bacterial DNA transcription into mRNA by inhibiting DNA-dependent RNA polymerase by binding its beta-subunit. 5-Bromouracil is used to treat neoplasms in the form of its nucleoside, 5-Bromo-2-deoxy-uridine. 6-Mercaptopurine is an analog of hypoxanthine and inhibits purine nucleotide synthesis and metabolism.

[#313] Heterosis results due to
Correct Answer

(D) None of these

Explanation

Solution: Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. Heterosis is due to the superiority per se of the heterozygous genotype compared to either parental homozygous genotype at individual loci, not due to Dominance, Over Dominance, or Epistasis.

[#314] Modification of proteins and packaging take place in
Correct Answer

(C) Golgi bodies

Explanation

Solution: Modification of proteins and packaging take place in Golgi bodies. Part of the endomembrane system in the cytoplasm packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination. It resides at the intersection of the secretory, lysosomal, and endocytic pathways. It is of particular importance in processing proteins for secretion, containing a set of glycosylation enzymes that attach various sugar monomers to proteins as the proteins move through the apparatus.

[#315] Match the following columns: Column I (International Institute) Column II (Location) a. International Board for Plant Genetic Resources 1. Ibadan (Nigeria) b. International Institute of Tropical Agriculture 2. Rome (Italy) c. International Laboratory for Research on Animal Disease 3. Hyderabad (India) d. ICRISAT 4. Nairobi (Kenya)
Correct Answer

(C) a-2, b-1, c-4, d-3

Explanation

Solution: a. International Board for Plant Genetic Resources located in Rome (Italy). The International Board for Plant Genetic Resources (IBPGR) is an international scientific organization under the aegis of the Consultative Group on International Agricultural Research (CGIAR) and was established by them in 1974. b. International Institute of Tropical Agriculture is located in Ibadan (Nigeria). The International Institute of Tropical Agriculture (IITA) is a nonprofit organisation that works with partners to enhance crop quality and productivity, reduce producer and consumer risks, and generate wealth from agriculture, with the ultimate goal of reducing hunger, malnutrition and poverty. c. International Laboratory for Research on Animal Disease is located in Nairobi (Kenya). It was established in Nairobi in 1973 by an agreement between the Government of Kenya and the Rockefeller Foundation acting for the Consultative Group on International Agricultural Research. d. ICRISAT is located in Hyderabad (India). The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) is an international organization that conducts agricultural research for rural development, headquartered in Patancheru (Hyderabad).