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प्रश्न
Who had proposed the chromosomal theory of the inheritance?
उत्तर
Sutton and Boveri independently proposed the chromosomal theory of inheritance in 1902. The two workers found a distinctive connection between the transmission of Mendelian hereditary elements (genes) and chromosome activity during gamete production and fertilisation. They proposed that Mendelian factors were carried on chromosomes. During meiosis, the chromosome, not the genes, segregates and assorts independently before recombining in the zygote during fertilisation. Morgan, Sturtevant, and Bridges enlarged upon the chromosomal theory of inheritance.
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संबंधित प्रश्न
If the number of chromosomes in an endosperm cell is 27, what will be the chromosome number in the definitive nucleus?
- 9
- 18
- 27
- 36
Describe the structure of chromosomes with a suitable diagram.
Classify the chromosomes on the basis of position of centromere.
Distinguish between X and Y chromosomes.
Give an account of artificial chromosomes in the transfer of genetic material.
The A and B genes are 10 cm apart on a chromosome. If an AB/ab heterozygote is test crossed to ab/ab, how many of each progeny class would you expect out of 100 total progeny?
A B B C C D E F G H I
From the above figure identify the type of mutation and explain it.
When two different genes came from the same parent they tend to remain together.
Write the observed phenotypic ratio.
Match the column I (Type of chromosome) with column II (name of chromosome).
| Type of chromosome | Name of chromosome | ||
| i. |  |
P. | Acrocentric |
| ii. |  |
Q. | Telocentric |
| iii. |  |
R. | Metacentric |
| iv. |  |
S. | Sub-metacentric |
From the following identify the statements that are CORRECT with respect to homologous and non-homologous region of X and Y chromosomes.
i. Non-homologous region of X chromosome is longer and contains more genes than that of non-homologous region of Y chromosome.
ii. X-linked genes are present on nonhomologous region of X-chromosome.
iii. Y-linked genes are present on homologous region of Y-chromosome.
iv. Crossing over occurs only between homologous regions of X and Y chromosomes.
Extra nuclear chromosomes occur in ______.
Extranuclear inheritance is a consequence of presence of genes in ______.
In a certain taxon of insects some have 17 chromosomes and the others have 18 chromosomes. The 17 and 18 chromosome-bearing organisms are ______.
Two or more independent genes present on different chromosomes which determine nearly same phenotype are called ______.
Chromosome maps/genetic maps were first prepared by ______.
A couple has two daughters. What is the probability that the third child will also be a female?
Which of the following phase follows S and G2 phases of interphase?
How do genes and chromosomes share similarity from the point of view of genetical studies?
A haemophilic man marries a carrier woman and they have a daughter. What is the probability of their daughter being haemophilic?
