10 Questions
What are chromosomes composed of?
Chromatin fibers
Who first described chromosomes in 1875?
Strausberger
What makes chromosomes visible during cell division?
Folding and coiling of chromatin fibers
What does the term 'chromosome' mean?
Colour body
When are chromosomes most easily counted?
During mitotic metaphase
Chromosomes are visible in active nucleus due to their high water content.
False
The term 'chromosome' was first used by Strausberger in 1875.
False
Chromosomes were given the name chromosome due to their marked affinity for acidic dyes.
False
Closely related species usually have different chromosome numbers.
False
Chromatin fibers undergo folding, coiling, and supercoiling during prophase to become thinner and larger.
False
Study Notes
What are Chromosomes?
- Chromosomes are rod-shaped, filamentous bodies present in the nucleus.
- They become visible during cell division.
- Chromosomes are carriers of genes or units of heredity.
Characteristics of Chromosomes
- Chromosomes are not visible in an active nucleus due to their high water content.
- Chromosomes can be seen clearly during cell division.
History of Chromosomes
- Chromosomes were first described by Strausberger in 1875.
- The term "Chromosome" was first used by Waldeyer in 1888.
- Chromosomes were named due to their affinity for basic dyes (Chromo = colour; Soma = body).
Composition and Structure
- Chromosomes are composed of thin chromatin threads called Chromatin fibers.
- Chromatin fibers undergo folding, coiling, and supercoiling during prophase, making chromosomes thicker and smaller.
Number of Chromosomes
- The number of chromosomes can be counted easily during mitotic metaphase.
- Normally, all individuals of a species have the same number of chromosomes.
- Closely related species usually have similar chromosome numbers.
Test your knowledge about chromosomes with this quiz! Learn about the structure, function, and history of chromosomes, the carriers of genetic information.
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