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प्रश्न
Answer the following question in your own words.
What is meant by ‘chromosome’?
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उत्तर
The structure in the nucleus of cells that carries the hereditary characteristics is called the chromosome. It is made up mainly of nucleic acids and proteins. During cell division chromosomes can be clearly seen under the compound microscope. ‘Genes’ which contain the information about hereditary characteristics in coded form are located on chromosomes. Each species has a specific number of chromosomes.
Each chromosome is made up of DNA and it appears dumbell-shaped midway during cell division. There is a constricted region on each chromosome. It is called the ‘Primary constriction’ or ‘Centromere’. This divides the chromosome into two parts. Each part is called an ‘arm’. The centromere has a specific position in each chromosome.
Organization of chromosome
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संबंधित प्रश्न
Name the sex chromosomes in human males and females
Correct the following statement if there is any mistake:
If there are 46 chromosomes in a cell, there will be 23 chromatin fibres inside the nucleus during interphase.
Choose the best option out of the four alternatives a, b, c and d
Question 1:
The number of chromosomes in a certain type of cell division is halved. This kind of cell
division occurs in.
(a) Only testis
(b) Only ovary
(c) Both ovary and testis
(d) All body cells
Humans have 46 chromosomes. Their sperms and eggs will have ______ chromosomes each.
State the difference between:
Chromosome and chromatid:
The component which is in the nuclei of cells and carries the hereditary characteristics is called ______.
Choose the correct answer:
Chromosomes number is halved in _____________
Choose the correct answer:
During mitosis which of the following disintegrate ___________
Mention the contribution of the scientist given below in the study of chromosome:
Sutton and Boveri
Explain the Term Leptotene
Give Technical Terms
The stage when sister chromosomes separate from their paired condition.
Name the following:
The number of chromosomes present in human gametes.
Name the following:
Pair of genes responsible for a particular characteristic.
Describe the structure of sex chromosomes with the help of labelled diagram.
Match the following.
| 1. Autosomes | - | Trisomy 21 |
| 2. Diploid condition | - | 9 : 3 : 3 : 1 |
| 3. Allosome | - | 22 pair of chromosome |
| 4. Down’s syndrome | - | 2n |
| 5. Dihybrid ratio | - | 23rd pair of chromosome |
Identify the TRUE statements with respect to aneuploidy.
- When the chromosome number is not the exact multiple of the haploid set, it is described as aneuploidy.
- Aneuploidy is only addition of one or more chromosome(s) to the total number of chromosomes in a cell.
- Aneuploidy is further classified as hypoploidy and hyperploidy.
In higher unisexual animals, one pair of chromosomes is not identical in two sexes. It is called as ______.
Which of the following is TRUE with respect to the genes which inherit together during crossing over?
