Genetics And Plant Breeding - Study Mode
[#541] The method recommended for germination test for small sized seeds are
Correct Answer
(C) Top of paper
Explanation
Solution: The method recommended for the germination test for small-sized seeds is Top of paper. In this method, seeds are placed directly on one or more layers of moist filter or blotter papers in Petri dishes or plastic boxes which are in turn kept for incubation. This method is used for small-sized crop seeds like ragi, jute, onion, tomato, etc.
[#542] The four stages of development of genetics upto 20 th century are
Correct Answer
(A) Lamarckism, Weismannism, Darwinism, Mendelism
Explanation
Solution: The four stages of development of genetics up to the 20 th century are Lamarckism, Weismannism, Darwinism and Mendelism. Lamarckism, also known as Lamarckian inheritance or neo-Lamarckism, is the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime. It is also called the inheritance of acquired characteristics or more recently soft inheritance. Weismannism's main contribution at one time also known as Weismannism, according to inheritance (in a multicellular animal) only takes place using the germ cells and the gametes such as egg cells and sperm cells. Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809 - 1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce. Mendelism is a term that refers to the single-gene trait's theoretical principles of heredity, which are taken from Gregor Mendel's principles, also known as Mendel's laws. Gregor Mendel conducted several experiments on pea plants for seven years and then postulated the laws of inheritance.
[#543] Multiplines are the mixture of
Correct Answer
(B) Isogenic lines
Explanation
Solution: Multiplines are the mixture of Isogenic lines. Multiline variety is a mixture of several pure lines of similar phenotype (height, seed colour flowering time, maturity time and various other agronomic characteristics) but has different genes for the character under consideration the disease resistance means these are isogenic lines. Isogenic lines are defined as individuals that possess the same genotype irrespective of their homo- or heterozygous nature.
[#544] The synthetic variety of maize was producesd by combining 10 lines the loss in vigour in F 2 generation is
Correct Answer
(C) 1 / 10
Explanation
Solution: The synthetic variety of maize was produced by combining 10 lines the loss in vigour in F 2 generation is 1 / 10 .
[#545] Brassica juncea is an amphidiploid between
Correct Answer
(B) B. nigra and B. campestris
Explanation
Solution: Brassica juncea is an amphidiploid between B. nigra and B. compestris. Brassica juncea L. belongs to the mustard family and has numerous common names used, e.g., brown mustard, Chinese mustard, or oriental mustard. Brassica juncea is an amphidiploid with 18 chromosomes having in its genetic system the A genome (Brassica campestris) and the 8-chromosome B genome (Brassica nigra). Considerable natural variability exists under the A genome.