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Question
What are genes?
Solution
Gene is a structural and functional unit of heredity and variations. Genes are specific sequences
of nucleotides on a chromosome that encode particular proteins which express in the form of
some particular feature of the body. In other words, gene is the DNA segment of the
chromosome and it controls the expression of characteristics
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RELATED QUESTIONS
What is the number of chromosomes in the gametes of human beings?
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 |
Humans have 46 chromosomes. Their sperms and eggs will have ______ chromosomes each.
Choose the correct answer:
Centromere is related to ________
Mention the contribution of the scientist given below in the study of chromosome:
Strasburger
Mention the contribution of the scientist given below in the study of chromosome:
Sutton and Boveri
Give Reasons for the following
The meiosis is called reductional division
Identify the stages of meiosven below and label them.
(i) Draw a neat labeled diagram to show the metaphase stage of mitosis in an animal cell having ‘6’ chromosome.
(ii) How many daughter cells are formed at the end of mitosis and at the end of meiosis?
(iii) With reference to cell division explain the following terms:
(Chromatid, Centromere, Haploid).
(iv) Name the type of cell division that occurs during:
1. Growth of shoot 2. Formation of pollen grains.
3. Repair of worn out tissues.
Complete the following sentence with appropriate word :
The spindle fibers are made of _______.
Name the following:
Pairs of chromosomes, present in human egg cells.
Give Technical Term:
Transmission of characters through generations.
Complete the following sentence with appropriate word:
The chromosomal theory of inheritance was proposed by ____________in 1902.
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 |
A male gorilla has 48 chromosomes in each of its body cells. How many chromosomes will each of the sperms have?
The chromosomes are duplicated in ______.
Distinguish between the following pair:
Karyotype and Karyokinesis
