Advertisements
Advertisements
प्रश्न
Describe the structure of sex-chromosomes.
Advertisements
उत्तर
Structure of X and Y chromosomes
- X chromosomes are longer than Y chromosomes.
- X chromosome contains large amount of euchromatin and small amount of
heterochromatin, whereas the Y chromosome contains small amount of euchromatin
and large amount of heterochromatin. - Non-homologous region of X-chromosome contains more genes than that of nonhomologous region of Y chromosome.
- Non-homologous region of X-chromosome contains X-linked genes while nonhomologous region of Y chromosome contains Y-linked genes.
APPEARS IN
संबंधित प्रश्न
A male honeybee has 16 chromosomes whereas its female has 32 chromosomes. Give one reason.
Distinguish between X andY chromosomes. (Mention any 'two' points.)
Answer the following question.
Compare in any three ways the chromosomal theory of inheritance as proposed by Sutton and Bovery with that of experimental results on pea plant presented by Mendel.
Mention the name of man-made cereal. How it is formed?
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 |
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.
According to the Chromosomal Theory of Inheritance, what are the specific positions on chromosomes where genes are located called?
According to the Chromosomal Theory of Inheritance, what is the source of one chromosome in each homologous pair of diploid organisms?
In what year did Walter Sutton publish the formal paper "The Chromosomes in Heredity" that linked Mendel's laws to chromosome behaviour?
