Tag: botany

Questions Related to botany

Chemical composition of chromosome : 

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. DNA and lipids

  2. DNA and carbohydrates

  3. Proteins and lipids

  4. DNA and proteins

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Correct Option: D
Explanation:

The chemical composition of a chromosome is DNA and proteins(histone). Because chromosome is a supercoiled structure made up by coiling of DNA on the proteins like histone

So the correct option is"DNA and Proteins".

How many sets are represented in the species with 156 chromosomes ?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. 12

  2. 78

  3. 39

  4. 19

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Correct Option: B
Explanation:

The single set of chromosome consists of half the total number of chromosomes, also called a haploid set. Here, a total of 156 chromosomes is there so one set will have 78 chromosomes.


So, the correct answer is ' B '

Chromosome have an ability of?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Autophagosis

  2. Self-replication

  3. Self-destruction

  4. None of these

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Correct Option: A

Study of _________ helps in the determination of phylogeny and taxonomy.

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Chromosomes

  2. Cytoplasm

  3. Nucleoplasm

  4. Sarcoplasm

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Correct Option: A

Who proposed that chromosomes carried a different set of heritable elements?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Walther Flemming

  2. Wilhelm Roux

  3. Robert Remark

  4. Virchow

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Correct Option: A

Who hypothesised that individuals of the same species have the same number of chromosomes?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Augustus Weisemann

  2. Theodor Boveri

  3. Wilhelm Roux

  4. Robert Remark

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Correct Option: A

Sometimes a few chromosomes have non staining secondary constriction at a constant location. This gives the appearance of a small fragment, called : 

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. NOR

  2. Satellite

  3. Telomere

  4. kinetochore

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Correct Option: A

Which of the following statements is incorrect?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Every chromosomes essentially has a secondary constriction

  2. The interphase nucleus has a loose and indistinct network of nucleoprotein fibres called chromatin

  3. A single human cell has approximately $2.2$ metre long thread of DNA distributed among its forty six chromosomes

  4. Chromatin contains DNA and some basic proteins called histone, some non histone proteins and also RNA

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Correct Option: A

What would be the number of chromosomes of the aleurone cells of a plant with $42$ chromosomes in its root tip cells?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. $21$

  2. $42$

  3. $63$

  4. $84$

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Correct Option: A

Chromosome consists of

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. DNA only

  2. DNA and histone protein

  3. DNA, histone proteins and non-histones proteins

  4. DNA and non-histones protein

Show answer
Correct Option: C
Explanation:

Chromosomes are made up of DNA and protein. Histone and non-histones proteins are associated with chromosomal DNA. Histone participate as structural components and provide strength and stability and protect DNA from shearing and breakage while the non-histones act as functional or regulatory components either in activation or repression of genes.

So, the correct answer is option C.