Genetics And Plant Breeding - Study Mode
[#661] The concept of physiological races was given by
Correct Answer
(A) Barrus (1911)
Explanation
Solution: The concept of physiological races was given by Barrus (1911). Physiological races are strains of a single pathogen species differing in their ability to attack different varieties of the same host species. The physiological race is a biotype or group of biotypes within a taxonomic group distinguished by some physiological peculiarity as host preference, chemical dependence, or pathogenicity used especially of economically important fungi, insects, or bacteria.
[#662] Dr. Har Govind Khurana was awarded the Nobel Prize in 1968 for his work on
Correct Answer
(C) Genetic code and in vitro synthesis of DNA
Explanation
Solution: Dr. Har Govind Khurana was awarded the Nobel Prize in 1968 for his work on Genetic code and in vitro synthesis of DNA. Har Gobind Khorana was an Indian American biochemist. While on the faculty of the University of Wisconsin-Madison, he shared the 1968 Nobel Prize for Physiology or Medicine with Marshall W. Nirenberg and Robert W. Holley for research that showed the order of nucleotides in nucleic acids, which carry the genetic code of the cell and control the cell's synthesis of proteins.
[#663] Protein synthesis takes place in
Correct Answer
(C) Ribosome
Explanation
Solution: Protein synthesis takes place in Ribosome. A ribosome is an intercellular structure made of both RNA and protein, and it is the site of protein synthesis in the cell. The ribosome reads the messenger RNA (mRNA) sequence and translates that genetic code into a specified string of amino acids, which grow into long chains that fold to synthesize proteins.
[#664] Which one of the following statements regarding selfing is correct
Correct Answer
(C) It reduces heterozygosity
Explanation
Solution: Selfing reduces heterozygosity. Selfing (self-pollination) is the ultimate form of inbreeding or mating among close relatives. It can create yield loss when inbreeding depression, defined as a lower survival and reproduction of inbred relative to outbred progeny, is present. Selfing increases homozygosity and reduces heterozygosity at a rate of 0.50 per generation. Increased homozygosity can uncover recessive deleterious variants and lead to inbreeding depression unless it is countered by the loss of these variants by genetic purging.
[#665] Wide crossing is also known as
Correct Answer
(A) Distant hybridization
Explanation
Solution: The wide crossing is also known as distant hybridization. Wide crossing refers to the process of undertaking a cross where one parent is from outside the immediate gene pool of the other. Wide hybridization or distant hybridization is crossing between two different species or genera and has been used successfully to move genes and to create new crop species.