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प्रश्न
Briefly mention the contribution of T.H. Morgan in genetics.
उत्तर
Thomas Hunt Morgan (1866-1945), an American geneticist and Nobel Prize winner in 1933, is recognised as the "Father of Experimental Genetics" for his work on and discovery of linkage, crossing over, sex linkage, criss-cross inheritance, linkage maps, gene mutability, and so on. He is known as the fly man of genetics because he used fruit flies (Drosophila melanogaster) as research subjects in experimental genetics. Genetics was mainly acknowledged as a unique discipline of biology as a result of his book "The Theory of Gene". In 1910, he identified linkage and discriminated between linked and unlinked genes. Morgan and Castle's (1911) "Chromosomal Theory of Linkage" argued that genes are located on chromosomes and ordered in linear order. Morgan and Sturtevant (1911) discovered that the frequency of crossover (recombination) between two connected genes is exactly proportional to their distance. 1% recombination is equivalent to 1 centi Morgan (cM) or 1 map unit. He researched on sex-linked inheritance and discovered a white-eyed male Drosophila in a red-eyed population, proving that the gene for eye colour is situated on the X-chromosome. The man passed genes on X-chromosomes to the daughter, whereas the son receives genes on X-chromosomes from the mother. It is known as criss-cross inheritance.
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संबंधित प्रश्न
If centromere is situated in the middle of the chromosome, it is called ________.
(a) Metacentric
(b) Acrocentric
(c) Submetacentric
(d) Telocentric
What is gene pool?
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Genes G S L H are located on the same chromosome. The recombination percentage is between L and G is 15%, S and L is 50%, H and S are 20%. The correct order of genes is
Write the salient features of the Sutton and Boveri concept.
Telocentric chromosome differs from acrocentric chromosome in that ____________.
Which of the following is a primary constriction?
During cell division, spindle fibres get attached to the disc shaped structures present on the centromere are known as ______.
From the following identify the INCORRECT statement/s with respect to the chromosomes.
i. Chromosomes are capable of self replication and play vital role in heredity, mutation, variation, and evolutionary development of eukaryotic species.
ii. Chromosomes are visible during cell division.
iii. Chemically eukaryotic chromosomes are made of mRNA, histone and non-histone proteins.
iv. The number of chromosomes varies within the population of a particular species.
Which of the following does NOT agree with chrotnosomal theory of inheritance?
A plant having the genotype AABbCC will produce ______ kinds of gametes.
Two or more independent genes present on different chromosomes which determine nearly same phenotype are called ______.
Experimental verification of ‘chromosomal theory of inheritance’ was done by ______.
Which of the following statements indicates parallelism in genes and chromosomes?
- They occur in pairs.
- They segregate during gamete formation.
- They show linkage.
- Independent pairs segregate independently.
What would be the genotype of the parents if the offspring have the phenotypes in 1:1 proportion?
Which of the following phase follows S and G2 phases of interphase?
Discuss in detail the contributions of Morgan and Sturvant in the area of genetics.
Which of the following is sex chromosomal disorder?
Consider the following information and answer the question that follows:
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Make a single pedigree chart using the above information to show the pattern of inheritance of phenylketonuria (PKU) in the family of Reshma.
