Genetics And Plant Breeding - Study Mode
[#236] Disease resistance in barley is
Correct Answer
(B) Qualitative characteristic
Explanation
Solution: Disease resistance in barley is a Qualitative characteristic. Qualitative disease resistance is effective against a particular pathogen race. Qualitative plant resistance traits produce discrete classes of resistant and susceptible individuals and segregate them as simple Mendelian loci.
[#237] Hyaloplasm means
Correct Answer
(B) The cytoplasm with membranous structure
Explanation
Solution: Hyaloplasm means the cytoplasm with a membranous structure. The hyaloplasm, which refers to the clear, nongranular, fluid portion of the cytoplasm of the cell, contains water, minerals, ions, amino acids, sugars, etc. It is also used to refer to the clear layer along the front margin of the cytoplasm during the locomotion of cells.
[#238] The C 4 -plants differ from the C 3 -plants with reference to the
Correct Answer
(D) All of the above
Explanation
Solution: The C 4 -plants differ from the C 3 -plants concerning the Compound that accept CO 2 in carbon assimilation, the Type of the first stable product produced, and also the Number of ATP's required from starch. C 3 photosynthesis produces a three-carbon compound via the Calvin cycle while C 4 photosynthesis makes an intermediate four-carbon compound that splits into a three-carbon compound for the Calvin cycle. The first stable compound produced in the Calvin cycle is a 3-carbon compound, which is 3 phosphoglyceric acid (PGA). In the C 4 plant, the first stable product is a 4-carbon compound, which is Oxaloacetic Acid (OAA). In the C 4 cycle of photosynthesis, a total of 30 ATPs are needed whereas, For the C 3 cycle to repair 6CO 2 , 18 ATPs are needed.
[#239] The chemical used to double the chromosome number is
Correct Answer
(D) colchicine
Explanation
Solution: The chemical used to double the chromosome number is colchicine. Colchicine is an important mutagen that works by preventing the formation of microtubules and doubles the number of chromosomes. It is commonly used to develop polyploid plants and functions as a mitotic poison by producing many mutagenic effects on plants. The most commonly used chemical agent for chromosome doubling is colchicine, which disrupts mitosis by inhibiting the formation of spindle fibers and disturbing normal polar chromosomal migration, resulting in chromosome doubling.
[#240] Who made first intergeneric cross between bread wheat and rye
Correct Answer
(B) Rimpau (1928)
Explanation
Solution: Rimpau (1928) made the first intergeneric cross between bread wheat and rye. Triticale is a hybrid of wheat ( Triticum ) and rye ( Secale ) first bred in laboratories during the late 19th century in Scotland and Germany by Wihelm Rimpau. Triticale combines the yield potential and grain quality of wheat with the disease and environmental tolerance (including soil conditions) of rye. The resulting hybrid is sterile and must be treated with colchicine to induce polyploidy and thus the ability to reproduce itself.