Genetics And Plant Breeding - Study Mode
[#476] Match the following columns: Column I (Name of the scientist) Column II (Area of the work) a. Jones 1. Law of homologous series in variation b. Tysdal 2. Poly cross test c. Muller 3. Double cross maize hybride d. Vavilov 4. X-ray induced mutations
Correct Answer
(B) a-3, b-2, c-4, d-1
Explanation
Solution: a. Jones worked in the area of double cross maize hybrid. Donald Forsha Jones (16 th April 1890 - 19 th June 1963) was a United States maize geneticist and practical corn breeder at the Connecticut Agricultural Experiment Station, New Haven. Beginning at the station in 1914, he made high-yielding hybrid corn practical with his invention of the double-cross hybrid. b. Tysdal proposed the technique of the Poly cross test. Poly cross is a cross in which the female parent is known but the male may belong to any of several available strains and which is used in the production of new lines of some economic plants. c. Muller gave his contribution to X-ray-induced mutations. Muller concluded that the x-ray exposure caused lethal mutations in the offspring of the x-ray-treated flies. He also found that mutations occurred in both the male and female flies when exposed to x-rays, indicating that both sexes were vulnerable to radiation-induced mutations. d. Vavilov worked on the Law of homologous series in variation. Species and genera are characterized by similar homologous series in their genetic variability. It is possible that by knowing a series of characters in the variability of one species, one may foresee parallel homologous characters for other related species and genera.
[#477] RNA & Protein synthesis takes place during which phase of cell cycle?
Correct Answer
(D) Both A and B
Explanation
Solution: RNA & Protein synthesis takes place during the G1 and G2 phases of the cell cycle. The primary function of RNA is to create proteins via translation. RNA carries genetic information that is translated by ribosomes into various proteins necessary for cellular processes. mRNA, rRNA, and tRNA are the three main types of RNA involved in protein synthesis. In G1 phase, the cell grows physically and increases the volume of both protein and organelles. And G2 phase involves further cell growth and organization of cellular contents.
[#478] Consider the following statements associated with self-incompatibility in crop plants 1. Heteromorphic system shows only gemetophytic control of self-incompatibility. 2. Both sporophytic and gametophytic controls of self-incompatibility are found in homomorphic system. Which of the statements given above is/are correct?
Correct Answer
(B) Only 2
Explanation
Solution: The following statements that are correct associated with self-incompatibility in crop plants are both sporophytic and gametophytic controls of self-incompatibility found in the homomorphic system. Self-incompatibility is a widespread mechanism in flowering plants that prevents inbreeding and promotes outcrossing. The self-incompatibility response is genetically controlled by one or more multi-allelic loci and relies on a series of complex cellular interactions between the self-incompatible pollen and pistil.
[#479] Sometimes the homologous chromosomes fail to pair in prophase of meiosis the situation is known as
Correct Answer
(C) Asynapsis
Explanation
Solution: Sometimes the homologous chromosomes fail to pair in the prophase of meiosis the situation is known as Asynapsis. Asynapsis is the complete failure of homologous chromosomes to pair or synapse during the first meiotic division. Both asynapsis and desynapsis have been found to play a significant role in the origin of polyploids via the formation of 2n gametes.
[#480] The fruit developed from single ovary is called as
Correct Answer
(B) Simple fruit
Explanation
Solution: The fruit developed from a single ovary is called Simple fruit. A type of fruit that develops from a single or compound ovary with only one pistil (of a single flower) is called a simple fruit. Such as Peach, tomato etc. Simple fruits are either fleshy or dry: Fleshy fruits are those fruits in which part or all of the pericarp is fleshy at maturity.