Advertisements
Advertisements
प्रश्न
State how does meiosis maintains chromosome number in a species.
उत्तर
The gametes are formed by meiosis. During meiosis the number of chromosomes is reduced to half i.e. the gametes contain haploid number of chromosomes. The male and female gametes fuse to form a diploid zygote. In this way meiosis maintains chromosome number in a species.
APPEARS IN
संबंधित प्रश्न
Give appropriate biological or technical terms for the following :
The condition in which a pair of chromosomes carries similar alleles of a particular character.
Match the events given in column A with the phase in mitotic cell division in column B.
| Column ‘A’ | Column ‘B’ | ||
| 1. | Chromosomes get arranged in a horizontal plane at the equator. |
a. | Anaphase |
| 2. | Daughter chromosomes move to the opposite poles of a spindle |
b. | Prophase |
| 3. | Chromosomes become visible as fine, long threads. |
c. | Telophase |
| 4. | Chromosomes lose their distinctiveness and gradually become transformed into a chromatin network. |
d. | Metaphase |
Answer the following question in your own words.
What is meant by ‘chromosome’?
Choose the correct answer:
In an interphase cell chromosome are as _____________
Choose the correct answer:
Chromosomes appear at equator in ____________
Choose the correct answer:
Minimum coiling in chromosome is at ______________
Choose the correct answer:
Chromosomes number is halved in ____________
Choose the correct answer:
Minimum coiling in chromosome is at ________________
Mention the contribution of the scientist given below in the study of chromosome:
Waldeyer
Give a reason for the following:
Gametes must be produced by meiosis for sexual reproduction.
Explain the Term Zygotene
Give Technical Terms
The stage at which the formation of chiasmata occurs.
Give Technical Terms
The phase of meiosis at which homologous chromosomes are separated.
Complete the following sentence with appropriate word :
Polytene chromosomes are found in _________ of fly larvae.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Chromosomes are the thickest and shortest in telophase.
Multiple Choice Question:
After mitotic cell division, a female human cell will have
Give Reason:
The Law of independent assortment holds good for the gene pairs that occur in different pairs of chromosomes.
Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with a suitable idea given in Column ‘I’.
| Column I | Column II |
| Genetics | Chromosomes are similar in size and shape. |
| Autosomes | The alternative forms of a gene. |
| Recessive gene | Study of laws of inheritance of characters |
| Allele | A gene that can express only when in a similar pair. |
| Homologous chromosomes | Chromosomes are other than the pair of sex chromosomes. |
Identify the odd one:-
Some of the chromosomes have an elongated knob-like appendages known as telomere.
